NOVAVAX INC

Note 1 –Organization & Business

Novavax, Inc. (“Novavax,” and together with its wholly owned subsidiaries, the “Company”) tackles some of the world’s most pressing health challenges with its scientific expertise in vaccines and its proven technology platform, including its Matrix-M™adjuvant and protein-based nanoparticles.

The Company’s corporate growth strategy focuses on maximizing the impact of its cutting-edge technology by forging partnerships for its Matrix-M adjuvant and research and development (R&D) assets while maintaining a lean and focused operating model.

All references to “NuvaxovidTM” or “COVID-19 Vaccine” refer to the Company’s Nuvaxovid™ COVID-19 vaccine; all references to "JN.1 COVID-19 Vaccine" refer to the Company’s NuvaxovidTM COVID-19 Vaccine for the 2025-2026 vaccination season.

Currently, the Company significantly depends on its supply agreement with Serum Institute of India Pvt. Ltd. (“SII”) and its subsidiary, Serum Life Sciences Limited (“SLS” and together with SII, “Serum”), for co-formulation, filling, and finishing of its COVID-19 Vaccine.

Note 2 –Summary of Significant Accounting Policies

Basis of Presentation

The consolidated financial statements include the accounts of Novavax, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated in consolidation.

Reclassifications

Certain amounts reported in prior periods have been reclassified to conform to current period financial statement presentation. These reclassifications have no material effect on previously reported financial position and cash flows. The Company reclassified $23.0 million and $16.5 million of revenue previously reported as License, royalties, and other revenue to Product sales for the years ended December 31, 2024 and December 31, 2023, respectively, related to adjuvant supply sales and other supply sales. This presentation aligns with the Company’s enhanced focus on supply sales to partners.

Liquidity and Going Concern

The consolidated financial statements have been prepared assuming that the Company will continue as a going concern within one year after the date that the financial statements are issued and contemplates the realization of assets and satisfaction of liabilities in the ordinary course of business. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of the uncertainty described below.

As of December 31, 2025, the Company had $240.6 million in cash and cash equivalents, $494.5 million in marketable securities, and working capital of $518.3 million. During the year ended December 31, 2025, the Company recognized net income of $440.3 million and had net cash flows used in operating activities of $244.6 million.

In accordance with Accounting Standards Codification (“ASC”) Topic 205-40, Presentation of Financial Statements - Going Concern, the Company evaluated its ability to continue as a going concern within one year after the date that the consolidated financial statements are issued. Based on the Company’s current cash, cash equivalents, and marketable securities balances and the Company's current cash flow forecast for the one-year going concern look forward period, the Company has concluded that it expects to have sufficient capital available to fund its operations for the one-year period from the date that these financial statements are issued.

Use of Estimates

The preparation of the consolidated financial statements in conformity with generally accepted accounting principles in the United States (“U.S. GAAP”) requires management to make estimates and assumptions that affect the reported amounts

F- 9 of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Actual results could differ materially from those estimates.

Revenue Recognition

At contract inception, the Company analyzes its revenue arrangements to determine the appropriate accounting under U.S. GAAP. Currently, the Company’s revenue arrangements represent customer contracts within the scope of ASC Topic 606, Revenue from Contracts with Customers(“ASC 606”). The Company recognizes revenue from arrangements within the scope of ASC 606 following the five-step model: (i) identify the contract(s) with a customer; (ii) identify the performance obligation(s) in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligation(s) in the contract; and (v) recognize revenue when (or as) it satisfies a performance obligation. The Company only recognizes revenue under the five-step model when it is probable that it will collect the consideration it is entitled to in exchange for the goods or services it transfers to its customer.

Product Sales - APAs and Supply Sales

Product sales include sales associated with COVID-19 Vaccine supply agreements, sometimes referred to as advanced purchase agreements (“APAs”), with various international governments and commercial sales of COVID-19 Vaccine, adjuvant sales, and sale of other materials to the Company’s partners. The Company recognizes revenue from product sales related to these APAs and supply sales to the Company’s partners based on the transaction price per dose or other unit sold calculated in accordance with ASC 606 at the point in time when control of the product transfers to the customer and customer acceptance has occurred, unless such acceptance provisions are deemed perfunctory, or expiry of optional dose order quantities. The APAs typically contain terms that include upfront payments, which are reflected in Deferred revenue. The Company constrains the transaction price for APA’s until it is probable that a significant reversal in revenue recognized will not occur. Specifically, if an APA or partner supply agreement includes a provision whereby the customer may request a discount, return, or refund, or includes a term that may have the effect of decreasing the price per dose of previously delivered shipments, revenue is constrained based on an estimate of the impact of the transaction price until it is probable that a significant reversal in revenue recognized will not occur.

Product Sales - U.S. Commercial

In the fourth quarter of 2023, the Company commenced sales of COVID-19 Vaccine to the U.S. commercial market. Product sales in the U.S. are primarily made through large pharmaceutical wholesale distributors at the wholesale acquisition cost (“WAC”). The Company recognizes revenue upon title transfer (which is typically at time of delivery), provided all other revenue recognition criteria have been met. The transaction price includes estimates of variable consideration for which reserves are established that primarily result from invoice discounts for prompt payment, wholesale distributor fees, chargebacks, and product returns (collectively, “gross-to-net deductions”). These estimates are based on the amounts earned or to be claimed for related sales and are classified as either reductions of gross accounts receivable or a current liability based on the nature of the estimate, the expected settlement method, and net position by individual customer. Where appropriate, these estimates are based on factors such as industry data and forecasted customer buying and payment patterns, the Company’s experience, current contractual and statutory requirements, specific known market events, and trends. Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. If actual results vary from estimates, the Company will adjust the estimates, which would affect product sales in the period such variances become known.

Gross-to-net deductions include the following:

•Wholesale distributor fees, discounts, and chargebacks: The Company has arrangements under which indirect customers such as retailers, healthcare providers, and others receive discounts to the WAC. The chargeback represents the difference between the WAC and this negotiated discounted price. For distribution and related services, the Company incurs service fees to its wholesale distributors. In addition, the Company typically offers wholesale distributor customers invoice discounts on product sales for prompt payments. The Company estimates chargebacks, discounts, and fees it will owe and deducts these amounts from gross product sales at the time the revenue is recognized based on the contractual terms and the Company’s expectations regarding future customer behaviors.

•Product returns: The Company offers wholesale distributors and indirect customers the right to return expired doses. Estimated returns for COVID-19 Vaccine are determined considering levels of inventory in the distribution channel,

F- 10 projected market demand, utilization data, returns claims received, and product shelf life. The estimated amount for product returns is deducted from gross product sales in the period the related product sales are recognized.

•Other: Fees payable to retailers, healthcare providers, and buying groups, including certain patient assistance programs, are deducted from gross product sales in the period the related product sales are recognized.

Licensing, royalties, and other

The Company also has various arrangements that include a right for a customer to use the Company's intellectual property as a functional license, where the Company’s performance obligation is satisfied at the point in time at which the license is granted. These licensing arrangements include sales-based royalties and certain development and commercial milestone payments. Because certain development milestone payments are contingent on the achievement of milestones, such as regulatory approvals, that are not within the Company or licensee's control, the payments are not considered probable of being achieved and are excluded from the transaction price until the milestone is achieved, at which point the Company recognizes revenue. For arrangements that include sales-based royalties related to a previously granted license, including milestone payments based upon the achievement of a certain level of product sales, the license is deemed to be the sole or predominant item to which the royalties relate and the Company recognizes revenue when the related sales occur.

The Company allocates the transaction price to each performance obligation based on a relative stand-alone selling price (“SSP”) basis. The Company develops assumptions that require judgment to determine the stand-alone selling price for each performance obligation in consideration of applicable market conditions and relevant entity-specific factors, including factors that were contemplated in negotiating the agreement with the customer.

Revenue Recognition, Licensing, Transition Services, and Technology Transfer

The terms of the Company’s third-party licensing agreements may contain multiple performance obligations, including licenses, transition services, and technology transfer. The Company evaluates licensing agreements under ASC 606 to determine the distinct performance obligations. Prior to recognizing revenue, the Company estimates the transaction price, including variable consideration that is subject to a constraint. Amounts of variable consideration are included in the transaction price to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur and when the uncertainty associated with the variable consideration is subsequently resolved. Total consideration may include nonrefundable upfront license fees, transition service fees, technology transfer fees, other payments based upon the achievement of specified milestones, and royalty payments based on product sales from licensed products.

For multiple performance obligation arrangements, the Company allocates the transaction price to each distinct performance obligation based on its SSP. The SSP is generally determined for each performance obligation based on the prices charged to customers, discounted cash flows, or using expected cost-plus margin. For stand-alone selling prices determined using discounted cash flows, the Company considers discounted, probability-weighted cash flows related to the performance obligation transferred. In developing such estimates, the Company applies judgment in determining the forecasted revenue, expected margins, and the discount rate. These estimates are subjective and require the Company to make assumptions about future cash flows. Revenue related to performance obligations satisfied at a point in time is recognized when the customer obtains control of the promised asset. For performance obligations recognized over time, the Company recognizes revenue using an input method to measure progress by utilizing costs incurred to-date relative to total expected costs. Under this process, the Company considers the costs that have been incurred to-date, as well as projections to completion using various inputs and assumptions, including, but not limited to, progress towards completion, labor costs and level of effort, material and subcontractor costs, and indirect administrative costs. Estimating the total cost at completion of the Company’s performance obligation under a contract is subjective and requires the Company to make assumptions about future activity and cost drivers. Changes in these estimates can occur for a variety of reasons and may impact the timing of revenue recognition on the Company’s contracts. Changes in estimates related to the process are recognized in the period when such changes are made on a cumulative catch-up basis.

Grants

Grant revenue included revenue from government contracts. The Company performed research and development under government funding, grant, license, and clinical development agreements. The revenue primarily consisted of funding under U.S. government contracts to advance the clinical development and manufacturing of COVID-19 Vaccine.

Under U.S. government contracts, the Company was entitled to receive funding on a cost-reimbursable or cost-reimbursable-plus-fixed-fee basis, to support certain activities related to the development, manufacture, and delivery of

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COVID-19 Vaccine to the U.S. government. The Company analyzed these contracts and determined that they are within the scope of ASC 606. The obligations under each of the contracts was not distinct in the context of the contract as they were highly interdependent or interrelated and, as such, they were accounted for as a single performance obligation. The transaction price under these arrangements was the consideration the Company expected to receive and consisted of the funded contract amount and the unfunded variable amount to the extent that it was probable that a significant reversal of revenue would not occur. The Company recognized revenue for these contracts over time as the Company transferred control over the goods and services and satisfied the performance obligation. The Company measured progress toward satisfaction of the performance obligation using an Estimate-at-Completion (“EAC”) process, which is a cost-based input method that reviews and monitors the progress towards the completion of the Company’s performance obligation. Under this process, management considered the costs that had been incurred to-date, as well as projections to completion using various inputs and assumptions, including, but not limited to, progress towards completion, labor costs and level of effort, material and subcontractor costs, indirect administrative costs, and other identified risks. Estimating the total allowable cost at completion of the performance obligation under a contract is subjective and required the Company to make assumptions about future activity and cost drivers. Allowable contract costs included direct costs incurred on the contract and indirect costs that were applied in the form of rates to the direct costs. Progress billings under the contracts were initially based on provisional indirect billing rates, agreed upon between the Company and the U.S. government. These indirect rates were subject to review on an annual basis. The Company records the impact of changes in the indirect billing rates in the period when such changes are identified. These changes reflect the difference between actual indirect costs incurred compared to the estimated amounts used to determine the provisional indirect billing rates agreed upon with the U.S. government. The Company recognized revenue on the U.S. government contracts based on reimbursable allowable contract costs incurred in the period up to the transaction price. For cost-reimbursable-plus-fixed-fee contracts, the Company recognized the fixed-fee based on the proportion of reimbursable contract costs incurred to total estimated allowable contract costs expected to be incurred on completion of the underlying performance obligation as determined under the EAC process. The Company recognizes changes in estimates related to the EAC process in the period when such changes are made on a cumulative catch-up basis. The Company includes the transaction price comprising both funded and unfunded portions of customer contracts in this estimate.

Cost of Sales

Cost of sales includes cost of raw materials, production, and manufacturing overhead costs associated with the Company’s product sales during the period. Cost of sales also includes adjustments for excess, obsolete, or expired inventory; idle capacity; and losses on firm purchase commitments to the extent the cost cannot be recovered based on estimates about future demand. Cost of sales does not include certain expenses related to raw materials, production, and manufacturing overhead costs that were expensed prior to regulatory authorization as described under the caption “Inventory.”

Research and Development Expenses

Research and development expenses include salaries; stock-based compensation; laboratory supplies; consultants and subcontractors, including external contract research organizations (“CROs”), contract manufacturing organizations (“CMOs”), and contract development and manufacturing organizations (“CDMOs”); and other expenses associated with the Company’s process development, manufacturing, clinical, regulatory, and quality assurance activities for its clinical development programs. In addition, related indirect costs such as fringe benefits and overhead expenses are also included in research and development expenses.

The Company estimates its research and development expense related to services performed under its contracts with external service providers based on an estimate of the level of service performed in the period. Research and development activities are expensed as incurred.

Accrued Research and Development Expenses

The Company accrues research and development expenses, including clinical trial-related expenses, as the services are performed, which may include estimates of those expenses incurred, but not invoiced. The Company uses information provided by third-party service providers and CRO, CMO, and CDMO invoices and internal estimates to determine the progress of work performed on the Company’s behalf. Assumptions based on clinical trial protocols, contracts, and participant enrollment data are also used to estimate these accruals.

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Advertising Costs

Advertising costs are expensed as incurred. The Company had advertising costs of $1.9 million, $33.7 million, and $91.5 million and during the years ended December 31, 2025, 2024 and 2023, respectively.

Stock-Based Compensation

The Company accounts for stock-based compensation related to grants of stock options, stock appreciation rights (“SARs”), and restricted stock awards (“RSUs”), and purchases under the Company’s Employee Stock Purchase Plan (“ESPP”), at fair value. The Company recognizes compensation expense related to such awards on a straight-line basis over the requisite service period (generally the vesting period) of the equity awards, based on the award's fair value at the grant date. The requisite service period is typicallyone tofour years. Forfeitures for all awards are recognized as incurred. The Company settles stock-based awards with newly issued shares.

The fair value of stock options and SARs is measured on the date of grant using the Black-Scholes option pricing model. The expected term of stock options and SARs is based on the Company’s historical option exercise experience and post-vesting forfeiture experience using the historical expected term from the vesting date, and the expected term for purchases under the ESPP is based on the purchase periods included in the offering. The expected volatility is determined using historical volatilities based on stock prices over a look-back period corresponding to the expected term. The risk-free interest rate is determined using the yield available for zero-coupon U.S. government issues with a remaining term equal to the expected term. The Company has never paid a dividend and the Company does not intend to pay dividends in the foreseeable future, and as such, the expected dividend yield is zero.

Cash and Cash Equivalents

Cash and cash equivalents consist of highly liquid investments with maturities of three months or less from the date of purchase. Cash equivalents are recorded at cost, which approximates fair value due to their short-term nature.

Marketable Securities

The Company invests its excess cash balances in marketable debt securities with readily determinable fair values that can be converted to cash to fund operations, as required. Investments with maturities greater than three months from the date of purchase are recorded in Current assets and are classified as “available-for-sale.”

Available-for-sale securities are measured at fair value in the consolidated balance sheets. Marketable securities are evaluated for impairment considering multiple factors including whether a decline in value below the amortized cost basis is due to credit-related factors. Management reviews criteria, such as the magnitude and duration of the decline, as well as the Company’s ability to hold the securities, including whether the Company will be required to sell a security prior to recovery of its amortized cost basis, the investment issuer’s financial condition and business outlook. A credit-related impairment is recognized as an allowance against the value of the investment on the balance sheet with a corresponding adjustment to Other income, net in the consolidated statements of operations. Unrealized gains and noncredit-related losses on marketable securities are reported as a separate component of stockholders’ deficit until realized.

Interest and dividend income is recorded when earned and included in Other income, net in the consolidated statements of operations. Premiums and discounts, if any, on marketable securities are amortized or accreted to maturity and included in Other income, net in the consolidated statements of operations. The specific identification method is used in computing realized gains and losses on the sale of the Company’s marketable securities.

Fair Value Measurements

The Company applies ASC Topic 820, Fair Value Measurements and Disclosures (“ASC 820”), for financial and non-financial assets and liabilities. ASC 820 discusses valuation techniques, such as the market approach (comparable market prices), the income approach (present value of future income or cash flow), and the cost approach (cost to replace the service capacity of an asset or replacement cost). ASC 820 utilizes a fair value hierarchy that prioritizes the inputs to valuation techniques used to measure fair value into three broad levels. The following is a brief description of those three levels:

•Level 1: Observable inputs such as quoted prices (unadjusted) in active markets for identical assets or liabilities.

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•Level 2: Inputs other than quoted prices that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active.

•Level 3: Unobservable inputs that reflect the reporting entity’s own assumptions.

Restricted Cash

The Company’s current and non-current restricted cash includes payments received under grant agreements and cash collateral accounts under letters of credit that serve as security deposits for certain facility leases. Payments received under grant agreements become unrestricted as the Company incurs expenses for services performed under these agreements.

Accounts Receivable

The Company recognizes amounts due from customers as accounts receivable when its right to payment is unconditional. Gross-to-net deductions are classified as reductions of gross accounts receivable if settlement is expected to occur through a reduction in the amount paid to the Company by its customer. Account receivables are recorded net of any allowance for credit losses. The Company’s estimate for the allowance for credit losses, which has not been significant to date, is determined based on the credit risk of its customers based on historical loss experience, economic conditions, the aging of receivables, and customer-specific risks.

Concentration of Risk

Financial instruments expose the Company to concentration of credit risk and consist primarily of cash and cash equivalents and marketable securities. The Company’s investment policy limits investments to certain types of instruments, including asset-backed securities, high-grade corporate debt securities, and money market funds; places restrictions on maturities and concentrations in certain industries; and requires the Company to maintain a certain level of liquidity. At times, the Company maintains cash balances in financial institutions that may exceed federally insured limits. The Company has not experienced any losses relating to such accounts and believes it is not exposed to a significant credit risk on its cash and cash equivalents and marketable securities.

The Company's accounts receivable arise from revenue arrangements with customers. The Company's revenue is primarily due to product sales; royalties, milestones, license fees, and reimbursements from its collaboration and license partners; and grants made by government-sponsored organizations. The following customers accounted for more than 10% of total revenue or accounts receivable for the periods presented:

*Amounts represent less than 10%

(1) Including the USG Agreement (as defined in Note 3).

The Company currently depends significantly on one supplier, SII and its subsidiary, SLS, for co-formulation, filling, and finishing of COVID-19 Vaccine. The loss of this supplier could prevent or delay the Company’s delivery of customer orders.

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Inventory

Inventory is recorded at the lower of cost or net realizable value under the First In, First Out methodology, taking into consideration the expiration of the inventory item. The Company determines the cost of raw materials using moving average costs and the cost of semi-finished and finished goods using a standard cost method adjusted on a periodic basis to reflect the deviation in the actual cost from the standard cost estimate. Standard costs consist primarily of the cost of manufacturing goods, including direct materials, direct labor, and the services and products of third-party suppliers. Manufacturing overhead costs are applied to semi-finished and finished goods based on expected production levels. The Company utilizes third-party CMOs, CDMOs, and other suppliers and service organizations to support the procurement and processing of raw materials, management of inventory, packaging, and the delivery process. Adjustments to reduce the cost of inventory to its net realizable value, if required, are made for estimated excess, obsolete, or expired inventory through cost of sales. At each reporting period, the Company assesses whether there are excess firm, non-cancelable, purchase commitment liabilities, resulting from supply agreements with third-party CMOs and CDMOs. The determination of net realizable value of inventory and firm purchase commitment liabilities requires judgment, including consideration of many factors, such as estimates of future product demand, current and future market conditions, potential product obsolescence, expiration and utilization of raw materials under firm purchase commitments, and contractual minimums.

Prior to initial regulatory authorization for its product candidates, the Company expenses costs relating to raw materials, production, and manufacturing overhead costs as Research and development expenses in the consolidated statements of operations, in the period incurred. Subsequent to initial regulatory authorization for a product candidate, the Company capitalizes the costs of production for a particular supply chain as inventory when the Company determines that it has a present right to the economic benefit associated with the product.

Property and Equipment

Property and equipment are stated at cost, net of accumulated depreciation. and are depreciated using the straight-line method over the estimated useful lives of the assets. Repairs and maintenance costs are expensed as incurred. The estimated useful lives of property and equipment are described below:

Lease Accounting

The Company enters into non‑cancelable lease agreements for facilities and certain equipment. For leases with a term greater than 12 months at the commencement date, the Company recognizes right‑of‑use (“ROU”) assets and corresponding lease liabilities based on the present value of fixed future lease payments over the lease term. The Company determines the present value of future payments using the discount rate implicit in the lease, if readily determinable, or the Company’s incremental borrowing rate.

For operating leases, the Company recognizes lease expense related to fixed payments on a straight-line basis from the lease commencement date through the end of the lease term and lease expense related to variable payments as incurred based on performance or usage in accordance with the contractual agreements. For finance leases, the Company recognizes the amortization of the ROU asset over the shorter of the lease term or useful life of the underlying asset. The Company expenses ROU assets acquired for research and development activities under ASC Topic 730, Research and Development, if they do not have an alternative future use, in research and development projects or otherwise.

The Company uses assumptions and judgment in evaluating its lease contracts and other agreements under ASC Topic 842, Leases (“ASC 842”),, including the determination of whether an agreement is or contains a lease; whether a change in the terms and conditions of a lease contract represent a new or modified lease; whether a lease represents an operating or finance lease; the discount rate used to determine the present value of lease obligations; and the Company’s incremental borrowing rate, which is determined using estimates such as the estimated value of the underlying leased asset and financial profile of comparable companies.

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Impairment of Long-Lived Assets

Long-lived assets, including property and equipment, internal-use software, and ROU assets, are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset (or asset group) may not be recoverable based on the criteria for accounting for the impairment or disposal of long-lived assets under ASC Topic 360, Property, Plant and Equipment(“ASC 360”). If such events or changes in circumstances occur, the Company assesses the recoverability of the long-lived assets (or asset group) by comparing their projected future undiscounted net cash flows over their remaining lives against their respective carrying amounts. If the cash flows are not expected to be sufficient to recover the carrying amount of the assets (or asset group), they are written down to their estimated fair values.

Restructuring

The Company recognizes restructuring charges when such costs are incurred. The Company’s restructuring charges consist of employee severance and other termination benefits related to the reduction of its workforce, as well as other costs related to the consolidation of facilities and infrastructure. Termination benefits are expensed on the date the company notifies the employee, unless the employee must provide future service, in which case the benefits are expensed ratably over the future service period. Ongoing benefits are expensed when restructuring activities are probable and the benefit estimable. Facility consolidation activities may include lease termination and related costs.

When the Company commits to a plan to sell a disposal group and meets the criteria for classification as held for sale under ASC 360, the disposal group is classified as held for sale. Upon classification, the disposal group is measured at the lower of its carrying amount or fair value less cost to sell, depreciation and amortization cease on included long‑lived assets (including ROU assets), and any resulting impairment loss is recognized immediately within Impairment of assets held for sale in the consolidated statements of operations. Any subsequent decreases in fair value less costs to sell are recognized in the period of change; subsequent increases are recognized not in excess of previously recognized losses. The assets and any associated liabilities are presented separately as current assets and current liabilities on the consolidated balance sheets, if the Company expects to divest the disposal group within 12 months.

Goodwill

Goodwill is subject to impairment tests annually or more frequently should indicators of impairment arise. The Company has determined that because its only business is an in-house early-stage R&D business to build a pipeline of high-value assets using its proven technology along with seeking to enter into partnerships to drive value creation for its assets, it operates as a single operating segment and hasone reporting unit. The one-step impairment test, which requires a comparison of the fair value of a reporting unit to its carrying value, including goodwill, is required to be applied to all reporting units including reporting units with zero or negative carrying value. A reporting unit with a zero or negative carrying value likely will not have an impairment. If the carrying value of the reporting unit exceeds its fair value, step two of the impairment analysis is performed. In step two of the analysis, an impairment loss is recorded equal to the excess of the carrying value of the reporting unit’s goodwill over its implied fair value, should such a circumstance arise.

As of December 31, 2025 and 2024, the Company had a negative carrying value and didnot have any impairment of goodwill.

Income Taxes

The Company accounts for income taxes in accordance with ASC Topic 740, Income Taxes. Under the liability method, deferred income taxes are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax basis and operating loss carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which those temporary differences are expected to be recovered or settled. The effect of changes in tax rates on deferred tax assets and liabilities is recognized in income in the period such changes are enacted. A valuation allowance is established when necessary to reduce net deferred tax assets to the amount expected to be realized.

The Global Intangible Low-Taxed Income (“GILTI”) provisions under the Tax Cuts and Jobs Act of 2017 impose U.S. tax on certain foreign income in excess of a deemed return on tangible assets of foreign corporations. The Company has elected to treat any potential GILTI inclusions as period costs.

Tax benefits associated with uncertain tax positions are recognized in the period in which one of the following conditions is satisfied: (1) the more-likely-than-not recognition threshold is satisfied; (2) the position is ultimately settled

F- 16 through negotiation or litigation; or (3) the statute of limitations for the taxing authority to examine and challenge the position has expired. Tax benefits associated with an uncertain tax position are reversed in the period in which the more-likely-than-not recognition threshold is no longer satisfied.

The Company has historically generated significant federal, state, and foreign tax net operating losses, which may be subject to limitation in future periods. Management has fully reserved the related deferred tax assets with a valuation allowance in the current reporting period as it is more likely than not that the related benefit will not be realized. The Company is currently subject to examination in all open tax years.

Net Income (Loss) per Share

Basic net income (loss) per share is computed by dividing net income (loss) by the weighted-average number of shares of common stock outstanding for the period and excludes the effects of any potentially dilutive securities.

Diluted net income per share (“Diluted EPS”) reflects the potential dilution from common stock equivalents and is computed using (i) the treasury stock method for stock options, SARs, and RSUs, and (ii) the if‑converted method for the Company’s convertible notes, in each case to the extent the effect is dilutive. When the Company issues new convertible notes and repays or otherwise extinguishes existing convertible notes in the same period, the retired notes are reflected in Diluted EPS, if dilutive, from the beginning of the period up to the repayment/extinguishment date and the new notes are reflected, if dilutive, from the issuance date through period‑end, each on a weighted‑average basis using the if‑converted method. Any gain or loss recognized upon extinguishment is reflected in net income for the period and included in the Diluted EPS numerator consistent with the income statement presentation, if the impact is dilutive.

As of December 31, 2025, the Company's 2031 Notes and the remaining portion of 2027 Notes (see Note 12) would have been convertible into approximately 22 million shares of the Company's common stock assuming the initial conversion price specified in their respective indentures. These shares, along with the related add‑back of interest expense, and amortization of discounts and debt issuance costs on the Notes, are included in Diluted EPS when their effect is dilutive and are excluded when their effect is antidilutive under the if‑converted method. For periods in which the Company reports a net loss, stock options, SARs, RSUs, and convertible notes are considered antidilutive and are excluded from diluted net income per share.

Foreign Currency

The consolidated financial statements are presented in U.S. dollars. The functional currency of the Company’s international subsidiaries is generally the local currency. The financial statements of international subsidiaries are translated to U.S. dollars using the exchange rate in effect at the consolidated balance sheet dates for assets and liabilities, historical rates for equity accounts, and average exchange rates for the consolidated statements of operations. Cash flows from operations are translated at the average exchange rate in effect for the period, while cash flows from investing and financing activities are translated at the exchange rate in effect at the date of the underlying transaction. Translation gains and losses are recognized as a component of accumulated other comprehensive income (loss) in the consolidated balance sheets. The foreign currency translation adjustment balance included in accumulated other comprehensive income (loss) was $2.0 million of income and $22.6 million of loss at December 31, 2025 and 2024, respectively. The aggregate foreign currency transaction gains and losses resulting from the conversion of the transaction currency to functional currency were $16.7 million of losses, $4.4 million of losses, $7.9 million of gains for the years ended December 31, 2025, 2024, and 2023, respectively, which are reflected in Other income (expense), net.

Segment Information

The Company manages its business asone operating segment, an in-house early-stage R&D business to build a pipeline of high-value assets using its proven technology along with seeking to enter into partnerships to drive value creation for its assets. Accordingly, it does not have separately reportable segments as defined by ASC Topic 280, Segment Reporting(“ASC 280”). The Company’s Chief Executive Officer (“CEO”) is its chief operating decision-maker (“CODM”). The accounting policies of this segment are described in Note 21.

Recent Accounting Pronouncements

Not Yet Adopted

In October 2023, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update 2023-06, Disclosure Improvements: Codification Amendments in Response to the SEC’s Disclosure Update and Simplification Initiative

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(“ASU 2023-06”), to clarify or improve disclosure and presentation requirements of a variety of topics and align the requirements in the FASB ASC with the SEC's regulations. The effective date for each amendment in the Update is the effective date that the SEC removes the disclosure requirement from its regulations. The Company is currently evaluating ASU 2023-06, however, as the ASU codifies SEC regulations, the Company does not anticipate that its implementation will have a material effect on the Company's consolidated financial statements and disclosures.

In November 2024, the FASB issued ASU 2024-03, Income Statement-Reporting Comprehensive Income-Expense Disaggregation Disclosures (Subtopic 220-40) (“ASU 2024-03”). The ASU includes enhanced disclosure requirements, which mandate transparency in financial statements by requiring detailed disclosures of specific expenses like inventory purchases, employee compensation, depreciation, and intangible asset amortization. ASU 2024-03 is effective for annual reporting periods beginning after December 15, 2026, and interim reporting periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of adopting this pronouncement on the Company’s consolidated financial statements and disclosures.

In September 2025, the FASB issued ASU 2025-06, Targeted Improvements to the Accounting for Internal-Use Software (“ASU 2025-06”). This standard is intended to improve the operability and application of guidance related to capitalized software development costs and becomes effective January 1, 2028. The Company is assessing the potential impact this ASU may have on the Company’s consolidated financial statements and disclosures upon adoption.

In December 2025, the FASB issued ASU 2025-11, Interim Reporting: Narrow-Scope Improvements (“ASU 2025-11”). The ASU is intended to improve the navigability of the guidance in ASC 270, Interim Reporting, and clarify when it applies. The amendments in this Update clarify interim disclosure requirements and the applicability of Topic 270. The ASU also includes a disclosure principle that requires entities to disclose events since the end of the last annual reporting period that have a material impact on the entity. The ASU is required to be adopted for interim periods within annual reporting periods beginning after December 15, 2027. Early adoption is permitted. The Company is currently evaluating the impact of adoption on the financial disclosures.

Adopted

In November 2023, the FASB issued ASU 2023-07, Segment Reporting (Topic 280): Improvements to Reportable Segment Disclosures (“ASU 2023-07”), which expands disclosures for reportable segments made by public entities and requires more detailed information about expenses within each reportable segment. Entities with a single reportable segment are required to provide on both an interim and annual basis, all segment disclosures required in ASC 280, including the new disclosures for reportable segments under the amendments in ASU 2023-07. The amendments do not change the existing guidance on how a public entity identifies and determines its reportable segments. The ASU is effective for the Company’s annual period ended December 31, 2024 and interim periods thereafter and has been adopted by the Company (see Note 21).

In December 2023, the FASB issued ASU 2023-09, Improvements to Income Tax Disclosures (“ASU 2023-09”). The standard enhances transparency in income tax disclosures by requiring, on an annual basis, certain disaggregated information about a reporting entity’s effective tax rate reconciliation and income taxes paid. The ASU also requires disaggregated disclosure related to pre-tax income (or loss) and income tax expense (or benefit) and eliminates certain disclosures related to the balance of an entity’s unrecognized tax benefit and the cumulative amount of certain temporary differences. The ASU is effective for the Company beginning on January 1, 2025 and has been prospectively adopted by the Company (see Note 17).

Note 3 –Revenue

The Company's accounts receivable, net, included $95.6 million and $102.9 million related to amounts that were billed to customers and $10.8 million and $5.4 million related to amounts which had not yet been billed to customers as of December 31, 2025 and 2024, respectively. During the years ended December 31, 2025 and 2024, changes in the Company's

F- 18 accounts receivables and deferred revenue balances and during the years ended December 31, 2025, 2024, and 2023, changes in the Company’s allowance for credit losses were as follows (in thousands):

(1) There wasno allowance for credit losses recorded during the year ended December 31, 2025 or 2024. In 2023, there was a $6.2 million reversal of a credit loss allowance due to the collection of a previously recognized allowance for credit losses. To estimate the allowance for credit losses, the Company evaluates the credit risk related to its customers based on historical loss experience, economic conditions, the aging of receivables, and customer-specific risks.

(2) Deductions from Deferred revenue generally relate to the recognition of revenue once performance obligations on a contract with a customer are met. During the year ended December 31, 2025, deductions include $555.7 million related to the Canada APA termination, discussed below. During the year ended December 31, 2024, additions included a $225.0 million reclassification of an upfront payment from Other current liabilities to Deferred revenue related to the settlement with Gavi as discussed below.

As of December 31, 2025, the aggregate amount of the transaction price allocated to performance obligations that were unsatisfied (or partially unsatisfied), excluding amounts related to sales-based royalties and constrained variable consideration, was $0.6 billion, of which $0.5 billion is included in Deferred revenue. Failure to meet regulatory milestones, obtain timely supportive recommendations from governmental advisory committees, or achieve product volume or delivery timing obligations may require the Company to refund portions of upfront and other payments or result in reduced future payments, which could adversely impact the Company’s ability to realize revenue from its unsatisfied performance obligations. The timing and the Company’s ability to fulfill performance obligations related to APAs will depend on the timing of product manufacturing, receipt of marketing authorizations for its COVID-19 Vaccine, delivery of doses based on customer demand, and the ability of the customer to request the Company’s updated vaccine under certain of the Company’s APAs. In the first quarter of 2025, the Company received written notice of a $23.0 million claim related to certain performance obligations under an APA agreement with a customer. The Company believes it has fulfilled the requirements related to this matter and is evaluating the merits of the claim. The timing to fulfill performance obligations related to the Sanofi Collaboration and License Agreement (“Sanofi CLA”) will depend on the timing of research and development transition services that support further regulatory approval and development of the COVID-19 Vaccine (“Sanofi Transition Services”) and services related to the technology transfer of the existing manufacturing process for the COVID-19 Vaccine products and Matrix-M™ adjuvant (the “Sanofi Technology Transfer”) and delivery of doses and other materials based on Sanofi demand.

Under an APA with Gavi, the Vaccine Alliance (“Gavi”), entered into in May 2021 (the “Gavi APA”), and a Termination and Settlement Agreement with Gavi, entered into in February 2024, (the “Gavi Settlement Agreement”) terminating the Gavi APA, the Company is responsible for deferred payments, in equal annual amounts of $80 million payable each calendar year through a deferred payment term ending December 31, 2028. The deferred payments are due in variable quarterly installments and total $400 million during the deferred payment term. Such deferred payments may be reduced through Gavi’s use of an annual vaccine credit equivalent to the unpaid balance of such deferred payments each year, which may be applied to qualifying sales of any of the Company’s vaccines for supply to certain low-income and lower-middle income countries. The Company has the right to price the vaccines offered to such low-income and lower-middle income countries in its discretion, and, when utilized by Gavi, the Company will credit the actual price per vaccine paid against the applicable credit. The Company intends to price vaccines offered via the tender process, consistent with its shared goal with Gavi to provide equitable access to those countries. Also, pursuant to the Gavi Settlement Agreement, the Company granted Gavi an additional credit of up to $225 million that may be applied against qualifying sales of any of the Company’s vaccines

F- 19 for supply to such low-income and lower-middle income countries that exceed the $80 million deferred payment amount in any calendar year during the deferred payment term. In total, the Gavi settlement agreement is comprised of $700 million of potential consideration, consisting of the $75 million initial settlement payment, deferred payments of up to $400 million that may be reduced through annual vaccine credits, and the additional credit of up to $225 million that may be applied for certain qualifying sales.

As of December 31, 2025, the remaining amounts included on the Company’s consolidated balance sheet were $225.0 in non-current Deferred revenue for the additional credit that may be applied against future qualifying sales, $80.0 million in Other current liabilities, and $195.0 million in Other non-current liabilities. In addition, the Company and Gavi entered into a security agreement pursuant to which Novavax granted Gavi a security interest in accounts receivable from SII under the SII R21 Agreement (see Note 4), which will continue for the deferred payment term of the Gavi Settlement Agreement.

Product Revenue

During the year ended December 31, 2025, 2024, and 2023, the categories of Product sales were as follows (in thousands):

(1)Nuvaxovid sales are sales of the Company’s COVID-19 Vaccine associated with APAs with governments and commercial markets, where the Company is the commercial lead for sales and distribution, made through pharmaceutical wholesale distributors.

(2)Supply sales include commercial sales of COVID-19 Vaccine, adjuvant sales, and other material sales to the Company’s partners.

During the years ended December 31, 2025 and 2024, changes in the Company’s gross-to-net deductions balances were as follows (in thousands):

(1) For the year December 31, 2025 and 2024, amounts charged against Product sales include $4.0 million and $14.4 million of adjustments made to prior period Product sales due primarily to changes in the estimate of product returns.

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As of December 31, 2025, there wereno gross-to-net deductions remaining on the consolidated balance sheet. As of December 31, 2024, $77.1 million of gross-to-net deductions were included in Accrued expenses, $10.1 million were included in Accounts payable, and $50.6 million were included in and reduced Accounts receivable on the consolidated balance sheet.

The Company has an APA with the Commonwealth of Australia (“Australia”) for the purchase of doses of COVID-19 Vaccine (the “Australia APA”). In December 2024, the Company entered into an amendment to the Australia APA pursuant to which, among other things, the Company acknowledged the cancellation by Australia of the delivery of certain doses of the Company’s COVID-19 Vaccine scheduled for delivery between the fourth quarter of 2023 and the fourth quarter of 2025 and the Company agreed to credit approximately $31 million of the advanced payment paid by Australia to the Company against outstanding invoices and invoices for the future delivery of approximately three million doses of COVID-19 Vaccine without requiring additional cash payments. In addition, the amendment provides for certain remedies for Australia, including return of unused credit, cancellation of doses, or termination of the Australia APA, in the event the Company is unable to gain regulatory approval of a variant COVID-19 Vaccine or supply doses per the terms of the agreement Specifically, Australia did not take delivery of doses that were due to be delivered in 2025 and may seek to cancel the future delivery of the 2025 as well as 2026 doses. If the Company is unable to provide doses per the supply schedule as amended, after six months, Australia may seek to terminate the APA. The amendment also provides Australia with the right to cancel doses if the Company fails to timely notify Australia of changes to the Company’s commercialization plans. In the event that the Company does not, on or before the relevant contractual deadlines, receive regulatory approval for, and deliver, the seasonally updated COVID-19 Vaccine, up to $92.5 million of deferred revenue may become refundable. As of December 31, 2025, $48.4 million was classified as current Deferred revenue and $85.4 million was classified as non-current Deferred revenue with respect to the Australia APA on the consolidated balance sheet, which will be recognized in product revenue as doses are delivered to Australia. In the third quarter of 2025, the Company withdrew its application for its COVID-19 Vaccine based on recommendations made by the TGA. The parties are in ongoing discussions and have agreed to a meeting to discuss outstanding issues and obligations under the APA. In light of these developments, the Company may seek to further amend the Australian APA, which amendment may not be achievable on acceptable terms or at all.

The Company had an APA with His Majesty the King in Right of Canada as represented by the Minister of Public Works and Government Services, as successor in interest to Her Majesty the Queen in Right of Canada, as represented by the Minister of Public Works and Government Services (the “Canadian government”), for the purchase of doses of COVID-19 Vaccine (the “Canada APA”). In March 2025, the Company received a communication (the “Notice”) terminating, with immediate effect, the Canada APA on the basis of the Company not receiving regulatory approval for its COVID-19 Vaccine using bulk antigen produced at Biologics Manufacturing Centre Inc. on or before December 31, 2024, pursuant to the terms of the Canada APA. As a result of the Notice, the Company has no remaining obligations to the Canadian government under the Canada APA. Therefore, during the first quarter of 2025, the Company recognized$575.7 million, previously recorded in Deferred revenue and Other current liabilities, as Product sales. As of December 31, 2024, the Company had$555.7 million of current deferred revenue and$48.0 million of other current liabilities related to advanced payments, and other commitments previously made under the Canada APA. Under the terms of the Canada APA,$28.0 million in advanced purchase payments previously received by the Company were refundable to the Canadian government within 30 days of receipt of the Notice. The Company repaid the$28.0 million in March 2025. The Canada APA, as amended in 2023, also contemplated the Company and the Canadian government would endeavor to enter into a memorandum of understanding (the “MOU”) related to certain in-country commitments, including a$20.0 million escrow funding. The Notice also acknowledged that such MOU is no longer feasible and that the related funds may be released to the Company.

In March 2025, the Pharmaceutical Management Agency (“Pharmac”), a New Zealand Crown entity, and the Company executed a Deed of Settlement and Release (“New Zealand Settlement Agreement”) of its APA (the “New Zealand APA”). As part of the New Zealand Settlement Agreement, the Company paid Pharmac a refund of previously received upfront payments of$4.0 million. Under the New Zealand Settlement Agreement, the Company has no remaining obligation to Pharmac under the New Zealand APA. Therefore, during the first quarter of 2025, the Company recognized$27.3 million, previously in other current liabilities, as Product sales. As of December 31, 2024, the Company had$31.3 million included in Other current liabilities in the Company’s consolidated balance sheet related to the New Zealand APA.

Licensing, Royalties, and Other

Licensing, royalties, and other includes licensing payments, transition services revenue, and technology transfer revenue from the Sanofi CLA; royalty and milestone payments; and sales-based royalties.

Licensing, royalties, and other by license partner for the year ended December 31, 2025, 2024, and 2023 were as follows (in thousands):

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(1)Other partners revenue includes royalties and license fees associated with agreements with other partners such as Serum and SK bioscience, Co., Ltd.

Sanofi licensing, royalties, and other revenue were comprised of the following (in thousands):

(1)Upfront fee amortization and Milestones amortization represent revenue recognized during the period related to a portion of the $500 million upfront payment and the $50 million milestone for database lock of an existing Phase 2/3 clinical trial in 2024 that were deferred upon achievement and are recognized in revenue over time. During the year ended December 31, 2025, the Company recognized a change in estimate to cumulative revenue recognized for the Sanofi Transition Services performance obligation of $21.7 million as further described in Note 4.

Takeda licensing, royalties, and other revenue were comprised of the following (in thousands):

(1)Upfront fee includes $14.5 million of nonrefundable upfront payments associated with the Amended Takeda CLA as defined below and $4.0 million of previously unrecognized consideration from the Original Takeda CLA.

Grants

The Company’s U.S. government agreement consists of a Project Agreement (the “Project Agreement”) and a Base Agreement with Advanced Technology International, the Consortium Management Firm acting on behalf of the Medical CBRN

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Defense Consortium in connection with the partnership formerly known as Operation Warp Speed (the Base Agreement together with the Project Agreement, the “USG Agreement”).

The original USG Agreement required the Company to conduct certain clinical, regulatory, and other activities, including a pivotal Phase 3 clinical trial to determine the safety and efficacy of the Company’s COVID-19 Vaccine, and to manufacture and deliver to the U.S. government 100 million doses of the vaccine candidate. Funding under the USG Agreement was payable to the Company for various development, clinical trial, manufacturing, regulatory, and other activities. The USG Agreement contained terms and conditions that were customary for U.S. government agreements of this nature, including provisions giving the U.S. government the right to terminate the Base Agreement or the Project Agreement based on a reasonable determination that the funded project would not produce beneficial results commensurate with the expenditure of resources and that termination would be in the U.S. government’s interest. If the Project Agreement was terminated prior to completion, the Company was entitled to be paid for work performed and costs or obligations incurred prior to termination and consistent with the terms of the USG Agreement. As of December 31, 2023, the Company recognized the full $1.8 billion funding in revenue.

Note 4 –Collaboration, License, and Supply Agreements

As of December 31, 2025, the Company’s material collaborations, license and supply agreements were as follows:

Sanofi

In May 2024, Novavax entered into the Sanofi CLA, to co-commercialize the Company’s COVID-19 Vaccine, including future updated versions that address seasonal COVID-19 variants. Under the terms of the agreement, the Company continued to commercialize its COVID-19 Vaccine through the end of the 2024-2025 vaccination season. Beginning in 2025 and continuing during the term of the Sanofi CLA, the Company and Sanofi will commercialize the COVID-19 Vaccine worldwide in accordance with a commercialization plan agreed by the parties, under which Novavax will continue to supply certain of its existing APA customers and strategic partners, including Takeda and SII. Upon completion of the existing APAs, the Company and Sanofi will jointly agree on commercialization activities of each party in each jurisdiction. Sanofi has the right to develop novel influenza-COVID-19 combination vaccines utilizing the Company’s COVID-19 Vaccine and Sanofi’s seasonal influenza vaccine, combination products containing the Company’s COVID-19 Vaccine and one or more non-influenza vaccines, and multiple new vaccines utilizing the Company’s Matrix-M™ adjuvant. The Company is also responsible for performing services related to Sanofi Technology Transfer. Until the successful completion of such transfer, the Company will supply Sanofi with both COVID-19 Vaccine products and Matrix-M™ intermediary components for Sanofi’s use and is eligible for reimbursement of such costs from Sanofi. In addition, the Company is responsible for Sanofi Transition Services and, in certain cases, is eligible for reimbursement of such costs from Sanofi.

Pursuant to the Sanofi CLA, the Company is eligible to receive development, technology transfer, launch, and sales milestone payments for COVID-19 Vaccine products, COVID-19-Influenza (“CIC”) products, and Adjuvant products. The Company is also eligible to receive royalty payments on Sanofi’s sales of such licensed products.

The Company is eligible to receive milestone payments totaling up to $350 million in the aggregate with respect to the COVID-19 Vaccine products, of which $75 million due upon completion of the technology transfer of the Company’s manufacturing process for the COVID-19 Vaccine products to Sanofi remains outstanding, and royalty payments in the high teens to low twenties percent on Sanofi’s sales of such licensed products. During the year ended December 31, 2025, the Company recognized $5.8 million of royalties on Sanofi sales of COVID-19 Vaccine products. The Company achieved the $50 million milestone for database lock of an existing Phase 2/3 clinical trial in 2024 and the $175 million milestone for the U.S. Food and Drug Administration (“U.S. FDA”) approval of the Biologics License Application (“BLA”) for the Company’s COVID-19 Vaccine product in a pre-filled syringe in 2025, both of which have been received from Sanofi. The Company also achieved the $25 million milestone for the transfer of the European Medicines Agency approval to Sanofi and the $25 million milestone for the transfer of the U.S. marketing authorization to Sanofi in 2025. As of December 31, 2025, the Company received $25 million in cash and included $25 million in Accounts receivable, net on the consolidated balance sheet.

The Company is eligible to receive milestone payments totaling up to $125 million with respect to CIC products upon achievement of certain CIC Product-related development milestones and $225 million in CIC Product-related launch milestones. The Company is eligible to receive royalty payments in the high teens to low twenties percent on Sanofi’s sales of such licensed products.

The Company is also eligible to receive development, launch, and sales milestone payments of up to $200 million for each of the first four Adjuvant Products and $210 million for each Adjuvant Product thereafter, and mid-single digit sales

F- 23 royalties for 20 years on Sanofi’s sales of all such licensed products. In addition, a portion of the technology transfer costs and R&D costs incurred by the Company will be reimbursed by Sanofi in accordance with agreed upon plans and budgets.

The Sanofi Transition Services and Sanofi Technology Transfer are recognized in revenue over time using an input method to measure progress by utilizing costs incurred to-date relative to total expected costs. Revenue recognized related to Sanofi Transition Services and Sanofi Technology Transfer for the years ended December 31, 2025 and 2024 was $155.6 million and $69.7 million, respectively. The Company’s consolidated balance sheet as of December 31, 2025 includes a deferred revenue balance of $35.6 million ($33.4 million included in Deferred revenue, current portion and $2.2 million included in Deferred revenue, non-current portion) related to Sanofi Transition Services and Sanofi Technology Transfer. The Company recognized a cumulative catch-up adjustment related to changes in estimates, which resulted in an increase to revenue of $21.7 million for the year ended December 31, 2025. These changes in estimates resulted from a change in both the total expected costs and the amount of variable consideration for Sanofi Transition Services, driven by a letter agreement with Sanofi executed in the third quarter of 2025 related to the postmarking commitment to conduct a Phase 4 prospective, randomized, double-blinded, placebo-controlled efficacy and safety trial in individuals aged 50 through 64 without high-risk conditions for severe COVID-19 requested as part of the FDA’s BLA approval. The Company also updated its estimates of expected costs and total variable consideration for additional manufacturing development activities related to the 2026-2027 vaccination season to be performed in support of Sanofi Transition Services.

The Company recognized an asset for $35.0 million of direct costs incurred to obtain the Sanofi CLA. These costs are amortized to expense over the expected period of the benefit in a manner that is consistent with the transfer of the related goods and services in the Sanofi CLA. The Company recognized $3.6 million and $29.1 million of amortization expense related to the asset in Selling, general, and administrative expense for the year ended December 31, 2025 and 2024, respectively. As of December 31, 2025, $2.3 million of these costs remain to be amortized in Prepaid expenses and other current assets on the consolidated balance sheet.

Takeda Pharmaceutical Company Limited

In April 2025, the Company entered into a collaboration and exclusive license agreement, as amended (“Amended Takeda CLA”), with Takeda which amended and superseded its collaboration and exclusive license agreement with Takeda, dated February 24, 2021 (“Original Takeda CLA”). The Original Takeda CLA, which granted Takeda an exclusive license to develop, manufacture, and commercialize the COVID-19 Vaccine in Japan, has been amended so that Takeda may develop and commercialize a strain for the COVID-19 Vaccine that is different from the strain that the Company selects for the year, provided such Takeda selected strain must be procured from the Company. Under the Amended Takeda CLA, Takeda will continue to purchase the Company’s Matrix-M™ adjuvant to manufacture doses of finished COVID-19 Vaccine with updated adjuvant forecast and other supply terms.

In connection with the Amended Takeda CLA, in April 2025, the Company entered into a release agreement with Takeda under which the Company released Takeda and Takeda released the Company from all claims that were asserted or could have been asserted by either party against the other party that related to the Original Takeda CLA and the activities thereunder.

The Company has determined that the Amended Takeda CLA represents a new contract under ASC 606 with the following performance obligations: the (i) delivery of an updated license to develop, manufacture, and commercialize the Company’s COVID-19 Vaccine in Japan, including the ability for Takeda to develop and commercialize a strain for the COVID-19 Vaccine that is different from the strain that the Company selects for the year (“Updated Takeda License”), and (ii) annual support services for Takeda’s regulatory and commercialization activities (“Takeda Support Services”). The Company will recognize revenue on optional purchases of Matrix-M™ adjuvant upon delivery to Takeda.

The Updated Takeda License performance obligation is considered functional intellectual property and distinct from other promises under the contract as Takeda can benefit from the license on its own or together with other readily available resources. The Takeda Support Services provide a distinct benefit to Takeda within the context of the contract, separate from the license, as the services could be provided by Takeda or another third party without the Company’s assistance.

The Company determined the initial transaction price at inception of the Amended Takeda CLA to be $27.5 million, consisting of (i) $19.5 million of the non-refundable upfront payment and royalties, (ii) $4.0 million of non-cancelable annual support payments within the 18-month notice period for contract termination, and (iii) $4.0 million of previously unrecognized consideration from the Original Takeda CLA. The transaction price excludes annual milestone payments and annual support payments that are not due in the event that the Amended Takeda CLA is terminated by Takeda after the 18-month notice period. Sales-based royalties and annual milestones relate to the Updated Takeda License performance obligation for which the

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Company will recognize revenue in the period that sales are made or annual milestones are achieved pursuant to the sales-based royalty exception under ASC 606. The Company will re-evaluate the transaction price in each reporting period as uncertain events are resolved or other changes in circumstances occur. The Company allocated $26.9 million of fixed consideration to the Updated Takeda License performance obligations and $0.6 million to Takeda Support Services.

The Company recognized revenue of $40.9 million related to the Updated Takeda License in 2025. The Takeda Support Services are recognized as revenue over time using an input method to measure progress by utilizing costs incurred to-date relative to total expected costs. Revenue recognized related to Takeda Support Services for the year ended December 31, 2025 was $0.8 million.

Under the Amended Takeda CLA, the Company received a non-refundable upfront payment of $19.5 million of which $5.0 million was creditable against royalties owed by Takeda for its fiscal year 2024. In addition, on an annual basis, the Company will receive $2.0 million to compensate it for services provided by the Company under the Amended Takeda CLA. If Takeda receives marketing approval of the COVID-19 Vaccine in that year or such approval is not necessary for such year, the Company will receive an additional $8.0 million annual milestone payment, of which $5.0 million is creditable against royalties owed by Takeda in its fiscal year 2025 or thereafter. The parties have also updated the financial terms to replace the share of operating profits and, instead, provide the Company with a tiered royalty as a percentage of Takeda’s, its affiliates’ and sublicensees’ total net sales in the mid to high-teen percentages (subject to certain capped royalty reductions), commencing on April 1, 2024 and will continue until the later of (a) twenty years after April 29, 2025, (b) all the Company’s know-how licensed under the Amended Takeda CLA has become publicly available through no fault of Takeda, and (c) the expiration of the last valid claim in the intellectual property rights licensed by the Company to Takeda under the Amended Takeda CLA covering COVID-19 Vaccine in Japan.

Serum

The Company previously granted SII exclusive and non-exclusive licenses for the development, co-formulation, filling and finishing, registration, and commercialization of its COVID-19 Vaccine and its CIC vaccine candidate. SII agreed to purchase the Company's Matrix-M™ adjuvant and the Company granted SII a non-exclusive license to manufacture the antigen drug substance component of the Company’s COVID-19 Vaccine in SII’s licensed territory solely for use in the manufacture of COVID-19 Vaccine. The Company and SII equally split the revenue from SII’s sale of COVID-19 Vaccine in its licensed territory, net of agreed costs. In May 2024, the Company and SLS entered into a supply agreement (the “SLS Supply Agreement”) under which SLS agreed to supply the Company with antigen drug substance and finished COVID-19 Vaccine doses. The SLS Supply Agreement includes the general terms and conditions of supply orders between the Company and SLS. The Company and SLS execute firm purchase orders, which include specific quantities to be delivered under the SLS Supply Agreement. The Company agreed to supply SLS with all Matrix-M™ adjuvant needed to manufacture finished COVID-19 Vaccine doses. In August 2022, the Company and SII entered into an influenza license agreement under which the Company granted SII licenses to develop, manufacture, and commercialize certain vaccine products including influenza vaccine products and influenza and CIC and is obligated for the purchase up to approximately $34 million of certain raw materials under related agreements with SII. In June 2025, the Company announced results of the initial cohort of its clinical study for its influenza and CIC vaccine candidates with the intent of partnering these programs. In March 2020, the Company entered into an agreement with SII that granted SII a non-exclusive license for the use of Matrix-M™ adjuvant supplied by the Company to develop, manufacture, and commercialize R21/Matrix-M™ adjuvant (“SII R21 Agreement”), a malaria vaccine created by the Jenner Institute, University of Oxford (“R21/Matrix-M™”). In December 2023, R21/Matrix-M™ received prequalification by the World Health Organization (“WHO”). Under the SII R21 Agreement, SII purchases the Company's Matrix-M™ adjuvant for use in development activities at cost and for commercial purposes at a tiered commercial supply price, and pays a royalty in the single-to low- double-digit range based on vaccine sales for a period of 15 years after the first commercial sale of the vaccine in each country.

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Note 5 –Earnings per Share

Basic and diluted net income (loss) per share were calculated as follows (in thousands, except per share data):

Note 6 –Cash, Cash Equivalents, and Restricted Cash

The following table provides a reconciliation of cash, cash equivalents, and restricted cash reported on the consolidated balance sheets that sum to the total of the same such amounts shown in the consolidated statement of cash flows (in thousands):

(1) Classified as Other non-current assets as of December 31, 2025 and 2024.

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Note 7 –Marketable Securities

Marketable securities classified as available-for-sale comprised of (in thousands):

As of December 31, 2025, investments in marketable securities comprised of $220.3 million of treasury securities, of which $162.4 million mature in 2026 and $57.9 million mature in 2027, $260.2 million of corporate debt securities, of which $250.9 million mature in 2026 and $9.3 million mature in 2027 and $14.0 million of agency securities maturing in 2027. Marketable securities are classified as Current assets in the consolidated balance sheets as of December 31, 2025 and 2024.

During the year ended December 31, 2025, 2024 and 2023, the Company recognized interest income of $29.5 million, $37.2 million, and $20.1 million respectively, from its investments in securities. Based on the Company’s policy under the expected credit loss model, including an assessment of the investment portfolio as of December 31, 2025, the Company concluded that any unrealized losses for its marketable securities were not attributable to credit and therefore an allowance for credit losses has not been recorded as of December 31, 2025. As of December 31, 2025, the Company heldno securities that were in an unrealized loss position for more than 12 months.

Note 8 –Fair Value Measurements

The following table represents the estimated fair value of the Company’s financial assets and liabilities (in thousands):

(1)Classified as cash and cash equivalents as of December 31, 2025 and 2024.

(2) Includes $34.8 million classified as cash and cash equivalents as of December 31, 2024.

Fixed-income investments categorized as Level 2 are valued at the custodian bank by a third-party pricing vendor’s valuation models that use verifiable observable market data, such as interest rates and yield curves observable at commonly quoted intervals and credit spreads, bids provided by brokers or dealers, or quoted prices of securities with similar

F- 27 characteristics. Pricing of the Company’s convertible notes has been estimated using observable inputs, including the price of the Company’s common stock, implied volatility, interest rates, and credit spreads.

During the years ended December 31, 2025 and 2024, the Company did not have any transfers between Levels.

The amount in the Company’s consolidated balance sheets for accounts payable and accrued expenses approximates its fair value due to its short-term nature.

Note 9 –Inventory

Inventory consisted of the following (in thousands):

Inventory write-downs as a result of excess, obsolescence, expiry, or other reasons, and losses on firm purchase commitments, offset by recoveries of such commitments, are recorded as a component of cost of sales in the Company’s consolidated statements of operations. For the year ended December 31, 2025, inventory write-downs were $1.9 million and losses on firm purchase commitments were $0.3 million. For the year ended December 31, 2024, inventory write-downs were $21.0 million and losses on firm purchase commitments, net of recoveries were $6.7 million.

Note 10 –Goodwill

The Company hasone reporting unit, which has a negative carrying amount as of December 31, 2025 and 2024. The change in the carrying amounts of goodwill was as follows (in thousands):

Note 11 –Leases

The Company has operating and finance leases for its research and development and manufacturing facilities, corporate headquarters and offices as well as embedded leases related to manufacturing supply agreements with CMOs. During the year ended December 31, 2025, as part of it’s global restructuring and cost reduction plan (“Restructuring Plan”), the Company classified its corporate headquarters facility at 700 Quince Orchard, Gaithersburg, Maryland (“700QO”), together with its related finance lease obligation, certain related property and equipment and land parcel adjacent to the facility (collectively referred to as the "Disposal Group"), as held for sale (see Note 19). As of December 31, 2025, the assets and liabilities of the Disposal Group were classified as held for sale and were presented separately in Current assets and Current liabilities on the consolidated balance sheet. As a result of this classification, the 700QO ROU asset and lease liability balance as of December 31, 2025, are excluded from the lease balances and related disclosures presented in the Supplemental balance sheet information table below.

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Supplemental balance sheet information related to leases as of December 31, 2025 and 2024 was as follows (in thousands, except weighted-average remaining lease term and discount rate):

Lease expense for the operating, short-term and finance leases for the years ended December 31, 2025, 2024, and 2023 was as follows (in thousands):

(1) During the year ended December 31, 2024 and 2023, the Company recognized a short-term lease benefit of $26.6 million and $48.0 million, respectively, due to gains on the settlement of manufacturing supply agreements with CMOs and CDMOs that included embedded leases.

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Supplemental cash flow information related to leases for the year ended December 31, 2025, 2024, and 2023 was as follows (in thousands):

As of December 31, 2025, maturities of lease liabilities were as follows (in thousands):

Note 12 –Long-Term Debt

The Company’s long-term debt consisted of the following (in thousands):

As of December 31, 2025 and December 31, 2024, the effective interest rate of the Convertible Senior Notes due 2027 is 6.2%. As of December 31, 2025, the effective interest rate of the Convertible Senior Notes due 2031 is 5.3%.

The interest expense incurred in connection with the convertible notes payable consisted of the following (in thousands):

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2031 Convertible Notes

In August 2025, the Company issued $225.0 million aggregate principal amount of its 4.625% Convertible Senior Notes due 2031 (the “2031 Notes”) consisting of (a) $175.3 million principal amount of 2031 Notes issued in exchange for $148.8 million principal amount of the Company’s 5.00% Convertible Senior Notes due 2027 (the “2027 Notes”), and (b) approximately $49.7 million principal amount of 2031 Notes issued for cash, in each case, pursuant to exemptions from registration under the Securities Act of 1933, as amended (the “Securities Act”), and the rules and regulations thereunder.

The 2031 Notes were issued pursuant to, and are governed by, an indenture (the “2031 Indenture”), dated as of August 27, 2025, between the Company and The Bank of New York Mellon Trust Company, N.A. as trustee.

The 2031 Notes are senior, unsecured obligations of the Company and accrue interest at a rate of 4.625% per annum, payable semi-annually in arrears on March 1 and September 1 of each year, beginning on March 1, 2026. The 2031 Notes will mature on September 1, 2031, unless earlier repurchased, redeemed or converted. Before June 1, 2031, noteholders have the right to convert their 2031 Notes only upon the occurrence of certain events. From and including June 1, 2031, noteholders may convert their 2031 Notes at any time at their election until the close of business on the second scheduled trading day immediately before the maturity date. The Company will settle conversions by paying cash, shares of its common stock or a combination of cash and shares of its common stock, at its election, based on the applicable conversion rate. The initial conversion rate is 89.7384 shares of common stock per $1,000 principal amount of 2031 Notes, which represents an initial conversion price of approximately $11.14 per share of common stock. The initial conversion price represents a premium of approximately 28% over the last reported sale price of the Company’s common stock on August 20, 2025. The conversion rate and conversion price will be subject to customary adjustments upon the occurrence of certain events. In addition, if certain corporate events that constitute a “Make-Whole Fundamental Change” (as defined in the 2031 Indenture) occur, then the conversion rate will, in certain circumstances, be increased for a specified period of time. The initial maximum conversion rate is 114.4164 shares of common stock per $1,000 principal amount of 2031 Notes.

The 2031 Notes are redeemable, in whole or in part (subject to certain limitations), for cash at the Company’s option at any time, and from time to time, on or after September 5, 2028 and before the 41st scheduled trading day immediately before the maturity date, but only if the last reported sale price per share of the Company’s common stock exceeds 130% of the conversion price for a specified period of time. However, the Company may not redeem less than all of the outstanding 2031 Notes unless at least $50.0 million aggregate principal amount of 2031 Notes are outstanding and not called for redemption as of the time the Company sends the related redemption notice. The redemption price is equal to the principal amount of the 2031 Notes to be redeemed, plus accrued and unpaid interest, if any, to, but excluding, the relevant redemption date.

Holders of the 2031 Notes will have the right to require the Company to repurchase all or part of their 2031 Notes for cash in the event of certain Fundamental Changes (as defined in the 2031 Indenture), at a repurchase price equal to 100% of the principal amount of the 2031 Notes to be repurchased, plus accrued and unpaid interest, if any, to, but excluding, the relevant repurchase date.

In accordance with ASC 470-50 Modification and Extinguishments, the Company determined that the modified terms of the $175.3 million principal amount of the 2031 Notes were substantially different than the terms of $148.8 million principal amount of the 2027 Notes they were exchanged for, and therefore, the exchange was accounted for as an extinguishment of the 2027 Notes and Issuance of 2031 Notes. The Company recorded a loss on debt extinguishment of $28.7 million related to the exchange.

The initial purchasers’ fees and the Company’s issuance costs related to the issuance of the 2031 Notes totaled $7.1 million, which were recorded as a reduction to the 2031 Notes on the consolidated balance sheet and is being amortized and recognized as additional interest expense over thesix-year contractual term of the 2031 Notes using the effective interest rate of 5.3%

2027 Convertible Notes

In December 2022, the Company issued $175.3 million aggregate principal amount of 5.0% Convertible Senior Notes that will mature on December 15, 2027 (the “2027 Notes”), unless earlier converted, redeemed, or repurchased. In August 2025, the Company exchanged $175.3 million aggregate principal amount of newly issued 2031 Notes for $148.8 million aggregate principal amount of 2027 Notes, as discussed above, after which $26.5 million aggregate principal amount of 2027 Notes remained outstanding. The 2027 Notes were issued in a private placement to qualified institutional buyers pursuant to Rule 144A under the Securities Act of 1933, as amended, and pursuant to an indenture dated December 20, 2022 (the “2027 Indenture”) between the Company and The Bank of New York Mellon Trust Company, N.A., as trustee. Concurrently with the

F- 31 issuance of the 2027 Notes, the Company completed a public offering of shares of its common stock. The Company received $166.4 million in net proceeds from the issuance of the 2027 Notes after deducting the initial purchasers’ fees and the Company’s offering expenses. The 2027 Notes bear cash interest at a rate of 5.0% per year, payable semiannually in arrears on June 15 and December 15 of each year, beginning on June 15, 2023.

The 2027 Notes are convertible at the option of the holders at any time prior to the close of business on the business day immediately preceding September 15, 2027, only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on March 31, 2023 (and only during such calendar quarter), if the last reported sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price for the 2027 Notes on each applicable trading day; (2) during thefive business day period after anyten consecutive trading day period (the “measurement period”) in which the trading price (as defined in the 2027 Indenture) per $1,000 principal amount of the 2027 Notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of the Company’s common stock and the conversion rate for the 2027 Notes on each such trading day; (3) if the Company calls such 2027 Notes for redemption, at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date, but only with respect to the 2027 Notes called (or deemed called) for redemption; and (4) upon the occurrence of specified corporate events as set forth in the 2027 Indenture. On or after September 15, 2027, until the close of business on the business day immediately preceding the maturity date (December 15, 2027), holders of the 2027 Notes may convert all or any portion of their 2027 Notes at any time, regardless of the foregoing conditions. Upon conversion, the Company may satisfy its conversion obligation by paying or delivering, as the case may be, cash, shares of the Company’s common stock, or a combination of cash and shares of the Company’s common stock, at the Company’s election, in the manner and subject to the terms and conditions provided in the 2027 Indenture.

The conversion rate for the 2027 Notes will initially be 80.0000 shares of the Company’s common stock per $1,000 principal amount of 2027 Notes, which is equivalent to an initial conversion price of $12.50 per share of common stock. The initial conversion price of the 2027 Notes represents a conversion premium of 25% of the public offering price in the Company’s concurrent common stock offering that closed on December 20, 2022. The conversion rate for the 2027 Notes is subject to adjustment under certain circumstances in accordance with the terms of the 2027 Indenture. In addition, following certain corporate events that occur prior to the maturity date of the 2027 Notes or if the Company delivers a notice of redemption in respect of the 2027 Notes, the Company will, under certain circumstances, increase the conversion rate of the 2027 Notes for a holder who elects to convert its 2027 Notes (or any portion thereof) in connection with such a corporate event or convert its 2027 Notes called (or deemed called) for redemption during the related redemption period (as defined in the 2027 Indenture), as the case may be.

The Company may not redeem the 2027 Notes prior to December 22, 2025. The Company may redeem for cash all or any portion of the 2027 Notes, at its option, on or after December 22, 2025, if the last reported sale price of the common stock has been at least 130% of the conversion price for the 2027 Notes then in effect for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period (including the last trading day of such period) ending on, and including, the trading day immediately preceding the date on which the Company provides notice of redemption at a redemption price equal to 100% of the principal amount of the 2027 Notes to be redeemed, plus accrued and unpaid interest, to, but excluding, the redemption date. If the Company redeems less than all the outstanding 2027 Notes, at least $50 million aggregate principal amount of 2027 Notes must be outstanding and not subject to redemption as of the date of the relevant notice of redemption. No sinking fund is provided for the 2027 Notes.

If the Company undergoes a Fundamental Change (as defined in the 2027 Indenture), holders may require, subject to certain conditions and exceptions as set forth in the 2027 Indenture, the Company to repurchase for cash all or any portion of their 2027 Notes at a Fundamental Change repurchase price equal to 100% of the principal amount of the 2027 Notes to be repurchased, plus accrued and unpaid interest, to, but excluding, the Fundamental Change repurchase date. If a holder of the 2027 Notes converted upon a Make-Whole Fundamental Change (as described in the 2027 Indenture), they may be eligible to receive a make-whole premium through an increase to the conversion rate up to a maximum of 20.0000 shares per $1,000 principal amount of 2027 Notes (subject to other adjustments as described in the 2027 Indenture).

In accounting for the issuance of the 2027 Notes, the Company determined that the scope exceptions provided under ASC Topic 815-40, Derivatives and Hedging – Contracts in Entity’s Own Equity (“ASC 815-40”) apply to all but one of the conversion features embedded in the 2027 Notes. This remaining conversion feature, which is associated with a Fundamental Change of the Company, was determined to have a de minimis value as of December 31, 2025, 2024, and 2023.

F- 32

The initial purchasers’ fees and the Company’s issuance costs related to the 2027 Notes totaled $8.8 million, which were recorded as a reduction to the 2027 Notes on the consolidated balance sheet. The $8.8 million of debt issuance costs is being amortized and recognized as additional interest expense over thefive-year contractual term of the 2027 Notes using an effective interest rate of 6.2%.

Note 13 –Stockholders’ Deficit

In August 2023, the Company entered into an At Market Issuance Sales Agreement (the “August 2023 Sales Agreement”), which allows it to issue and sell up to $500 million in gross proceeds of shares of its common stock, and terminated its then-existing At Market Issuance Sales agreement entered in June 2021 (the “June 2021 Sales Agreement”). As of December 31, 2025, the remaining balance available under the August 2023 Sales Agreement was approximately $51 million.

During the year ended December 31, 2024, the Company sold 12.2 million shares of its common stock under its August 2023 Sales Agreement, resulting in net proceeds of approximately $188 million. No shares were sold during the year ended December 31, 2025.

In May 2024, the Company also entered into the Sanofi Subscription Agreement, pursuant to which the Company sold and issued to Sanofi, in a private placement,6.9 million shares of the Company’s common stock, par value $0.01 per share at a price of $10.00 per share, for aggregate gross proceeds to the Company of $68.8 million.

Note 14 –Stock-Based Compensation

Equity Plans

In January 2023, the Company established the 2023 Inducement Plan (the “2023 Inducement Plan”), which provides for the granting of share-based awards to individuals who were not previously employees, or following a bona fide period of non-employment, as an inducement material to such individuals entering into employment with the Company. The Company reserved 1.0 million shares of common stock for grants under the 2023 Inducement Plan. As of December 31, 2025, there were 0.1 million shares available for issuance under the 2023 Inducement Plan.

The 2015 Stock Incentive Plan, as amended (“2015 Plan”), was approved at the Company’s annual meeting of stockholders in June 2015. Under the 2015 Plan, equity awards may be granted to officers, directors, employees, and consultants of and advisors to the Company and any present or future subsidiary.

The 2015 Plan authorizes the issuance of up to 27.5 million shares of common stock under equity awards granted under the 2015 Plan. All such shares authorized for issuance under the 2015 Plan have been reserved. The 2015 Plan will expire on March 30, 2033. As of December 31, 2025, there were 6.7 million shares available for issuance under the 2015 Plan.

The Amended and Restated 2005 Stock Incentive Plan (“2005 Plan”) expired in February 2015 and no new awards may be made under such plan, although awards will continue to be outstanding in accordance with their terms.

The 2023 Inducement Plan and the 2015 Plan permit, and the 2005 Plan permitted, the grant of stock options (including incentive stock options), restricted stock, stock appreciation rights (“SARs”), and restricted stock units (“RSUs”). In addition, under the 2023 Inducement Plan and the 2015 Plan, unrestricted stock, stock units, and performance awards may be granted. Stock options and SARs generally have a maximum term often years and may be or were granted with an exercise price that is no less than 100% of the fair market value of the Company’s common stock at the time of grant. Grants of share-based awards are generally subject to vesting over periods ranging from one toone tofour years.

F- 33

The Company recorded stock-based compensation expense in the consolidated statements of operations as follows (in thousands):

During the year ended December 31, 2023, total stock-based compensation capitalized in inventory was $0.5 million. No stock-based compensation was capitalized in inventory during the year ended December 31, 2025 and 2024.

As of December 31, 2025, there was approximately $42 million of total unrecognized compensation expense related to unvested stock options, SARs, RSUs, and the ESPP. This unrecognized non-cash compensation expense is expected to be recognized over a weighted-average period of approximately 1.1 years and will be allocated between cost of sales, research and development, and general and administrative expenses accordingly. This estimate does not include the impact of other possible stock-based awards that may be made during future periods.

The aggregate intrinsic value represents the total intrinsic value (the difference between the Company’s closing stock price on the last trading day of the period and the exercise price, multiplied by the number of in-the-money stock options and SARs) that would have been received by the holders had all stock option and SARs holders exercised their stock options and SARs on December 31, 2025. This amount is subject to change based on changes to the closing price of the Company’s common stock. The aggregate intrinsic value of stock options and SARs exercises and vesting of RSUs for the years ending December 31, 2025, 2024, and 2023 was approximately $20 million, $13 million, and $5 million, respectively.

Stock Options and Stock Appreciation Rights

The following is a summary of stock options and SARs activity under the 2023 Inducement Plan, 2015 Plan and the 2005 Plan for the year ended December 31, 2025:

F- 34

The fair value of stock options granted under the 2023 Inducement Plan and the 2015 Plan was estimated at the date of grant using the Black-Scholes option-pricing model with the following assumptions:

The total aggregate intrinsic value and weighted-average remaining contractual term of stock options and SARs outstanding under the 2023 Inducement Plan and 2005 Plan as of December 31, 2025 was less than$1.3 million and 7.5 years, respectively. The total aggregate intrinsic value and weighted-average remaining contractual term of stock options and SARs exercisable under the 2023 Inducement Plan and 2005 Plan as of December 31, 2025 was less than$0.7 million and 5.8 years, respectively.

Restricted Stock Units

The following is a summary of RSU activity for the year ended December 31, 2025:

Employee Stock Purchase Plan

The ESPP was approved at the Company’s annual meeting of stockholders in June 2013. The ESPP currently authorizes an aggregate of 2.3 million shares of common stock to be purchased, and the aggregate amount of shares will continue to increase 5% on each anniversary of its adoption up to a maximum of 3.5 million shares. The ESPP allows employees to purchase shares of common stock of the Company at each purchase date through payroll deductions of up to a maximum of 15% of their compensation, at 85% of the lesser of the market price of the shares at the time of purchase or the market price on the beginning date of an option period (or, if later, the date during the option period when the employee was first eligible to participate). At December 31, 2025, there were 0.5 million shares available for issuance under the ESPP.

Note 15 –Employee Benefits

The Company maintains a defined contribution 401(k) retirement plan, pursuant to which employees may elect to contribute up to 100% of their compensation on a tax deferred basis up to the maximum amount permitted by the Internal Revenue Code of 1986, as amended. The Company matches 100% of the first 3% of the participants’ deferral, and 50% on the next 2% of the participants’ deferral, up to a potential 4% Company match. The Company’s matching contributions to the 401(k) plan vest immediately. Under its 401(k) plan, the Company has recorded expense of $4.5 million, $5.5 million, and $7.0 million in 2025, 2024, and 2023, respectively.

The Company’s foreign subsidiaries have pension plans under local tax and labor laws and are obligated to make contributions to the plan. Contributions and other expenses related to these plans were $2.7 million, $2.6 million, and $3.0 million in 2025, 2024, and 2023, respectively.

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Note 16 –Other Financial Information

Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consist of the following as of (in thousands):

Property and Equipment, net

Property and equipment is comprised of the following as of (in thousands):

During the three months ended September 30, 2025, the Company classified its leasehold interest in 700QO, certain related property and equipment and land parcel adjacent to the facility, as held for sale. In October 2025, the Company executed an agreement to assign the lease, sell the adjacent land parcel, and transfer specified property and equipment for an aggregate consideration of $59.8 million (see Note 19). As a result of this classification, the related assets were not included in the Company’s December 31, 2025 property and equipment ending balances. In December 2024, the Company sold approximately $135 million of property and equipment, net, representing the Company’s biologics manufacturing campus and other moveable assets and equipment located in the Czech Republic (see Note 20). Depreciation and amortization expense was approximately $28 million, $48 million, and $41 million for the years ended December 31, 2025, 2024, and 2023, respectively.

Accrued Expenses

Accrued expenses consist of the following as of (in thousands):

F- 36

Other Current Liabilities

Other current liabilities consist of the following as of (in thousands):

Other Non-Current Liabilities

Other non-current liabilities consist of the following as of (in thousands):

(1) In November 2024, the Company and Secretary of State for Business, Energy and Industrial Strategy (as assigned to the UK Health Security Agency), acting on behalf of the government of the United Kingdom of Great Britain and Northern Ireland (the “UK Authority”) entered into a settlement agreement, which resolved disputes regarding the supply agreement with the UK Authority. Under the terms of the settlement agreement the Company agreed to repay previously received upfront payments in equal installment payments to the UK Authority. The remaining payments due to the UK Authority are classified as Other current liabilities and Other non-current liabilities on the Company’s consolidated balance sheet.

Note 17 –Income Taxes

The Company’s income (loss) before income tax expense by jurisdiction is as follows (in thousands):

Significant components of the current and deferred income tax expense (benefit) are as follows (in thousands):

A reconciliation of the provision for income taxes to the amount computed by applying the 21% statutory U.S. federal income tax rate to income before income taxes after the adoption of ASU 2023-09 is as follows:

(1) State and local income taxes in Maryland and Pennsylvania made up the majority (greater than 50 percent) of the tax effect in this category.

(2) Amounts in this category include the tax impact of share-based compensation windfalls, shortfalls and option cancellations.

A reconciliation of the provision for income taxes to the amount computed by applying the 21% statutory U.S. federal income tax rate to income (loss) before income taxes for years prior to the adoption of ASU 2023-09 is as follows:

The Company’s income taxes paid, net of refunds received by jurisdiction for the year ended December 31, 2025 is as follows (in thousands):

As of December 31, 2025, the Company has available federal, state, and foreign net operating losses of $2.6 billion, $824.1 million, and $10.9 million, respectively, that may be applied against future taxable income in the respective jurisdiction. The federal net operating losses of $2.6 billion may be carried forward indefinitely, except for $9.6 million which expires in 2037, limited to use equal to 80% of future annual federal taxable income. State net operating losses of $450.9 million have various expiration dates between 2028 and 2045. The remaining state and foreign net operating losses of $373.1 million and $10.9 million, respectively, can be carried forward indefinitely. The Company also has federal research tax credits of $50.9 million that will expire from 2026 through 2043 and a state research tax credit of $1.3 million that will expire from 2028 through 2030. Utilization of the federal and state net operating loss carryforwards and research tax credits may be subject to an annual limitation due to potential future ownership changes of the Company. As of December 31, 2025, the Company does not expect such limitation, if any, to impact the use of its net operating losses and research tax credits.

The Company files income tax returns in the U.S. federal jurisdiction and in various states, as well as in multiple foreign jurisdictions, including Sweden and the Czech Republic. The Company has U.S. federal and state net operating losses and credit carryforwards that are subject to examination from 2002 through 2024. The returns in Sweden are subject to examination from 2016 through 2025 and the returns for the Czech Republic are subject to examination from 2019 through 2025.

The significant components of the Company’s deferred tax assets and liabilities as of December 31 are as follows (in thousands):

The Company has evaluated the positive and negative evidence bearing upon the realization of its deferred tax assets, including its history of significant losses in every year since inception except the current year and, in accordance with U.S GAAP, has fully reserved the net deferred tax assets. The Company concluded that realization of its net deferred tax assets is not more-likely-than-not to be realized as of December 31, 2025 and 2024. The valuation allowance decreased by $109.8 million and increased by $6.6 million for the years ended December 31, 2025 and 2024, respectively. The net change was due to the income (loss) before taxes generated in each year.

The net deferred tax liability of $0.5 million and $0.4 million at December 31, 2025 and 2024, respectively, is included within Other non-current liabilities on the consolidated balance sheets.

The Company recognizes the effect of an income tax position when it is more likely than not, based on the technical merits, that the income tax position will be sustained upon examination. A reconciliation of the beginning and ending amounts of unrecognized tax benefits in the year ended December 31, 2025, 2024, and 2023 is as follows (in thousands):

The Company’s policy is to recognize interest and penalties related to income tax matters in income tax expense. As of December 31, 2025 and 2024, the Company had no accruals or expenses for interest or penalties. The total amount of unrecognized tax benefits that, if recognized, could affect the effective tax rate was $4.0 million and $4.1 million as of December 31, 2025 and 2024, respectively. However, the Company maintains a full valuation allowance as of December 31, 2025 and 2024 and the recognition of any unrecognized tax benefits would be offset with a change in the valuation allowance and therefore there would be no income statement impact. As of December 31, 2025, the Company does not expect a significant change in the recorded unrecognized tax benefits liability balance during the next twelve months. The unrecognized tax benefits are presented in the financial statements as a reduction to the deferred tax assets for all periods.

In December 2025, the Company received a notification that the Internal Revenue Service has initiated an examination of the Company’s U.S. federal income tax return for the 2023 tax year. The examination is in its early stages.

On July 4, 2025, President Trump signed into federal law H.R. 1 – One Big Beautiful Bill Act (the “Act”). Included in the Act are several corporate federal income tax considerations that will be relevant to the Company, specifically with respect to tax depreciation for specified fixed asset additions, capitalization of R&D costs, the deductibility of interest expense and certain federal tax rules with respect to the taxation of international operations. The Act has not had a significant impact on the Company’s effective income tax rate and its net deferred federal income tax assets as the Company maintains a full valuation allowance.

In 2021, the Organization for Economic Cooperation and Development (“OECD”) developed guidance on Base Erosion and Profit Shifting (“BEPS”) Pillar Two Model Rules (“Pillar Two”), which addresses corporate tax planning strategies used by some large multinational corporations to shift profits from higher-tax jurisdictions to lower-tax jurisdictions or zero-tax locations. This guidance imposes a 15% minimum tax on the earnings of large multinational corporations. Pillar Two is effective in 2024 for the jurisdictions in which the Company operates. These rules have not had a significant impact on the Company’s effective tax rate or its consolidated financial statements.

Note 18 –Commitment and Contingencies

Legal Matters

The Company is involved in various legal proceedings arising in the normal course of business. Although the outcomes of these legal proceedings are inherently difficult to predict, the Company does not expect the resolution of these legal proceedings to have a material adverse effect on its financial position, results of operations, or cash flows.

Purchase Commitments

The Company has entered into agreements in the normal course of business with CMOs and CDMOs supplying the Company with production capabilities, and with vendors for preclinical studies, clinical trials, and other goods or services. Certain agreements provide for termination rights subject to termination fees. Under such agreements, the Company is contractually obligated to make payments to vendors, mainly to reimburse them for their estimated unrecoverable expenses. The exact amount of such obligations are dependent on the timing of termination and the terms of the relevant agreement, and cannot be reasonably estimated. As of December 31, 2025, most of these agreements were active ongoing arrangements and the Company expects to receive value from these arrangements in the future. The Company recognizes fees related to obligations for terminated contracts where such fees are reasonably estimable. The Company did not accrue obligations that were not reasonably estimable. As of December 31, 2025, the Company had $2.7 million of non-cancelable purchase commitments with a remaining term of more than one year.

Note 19 –Restructuring

During the three months ended September 30, 2025, the Company classified its corporate headquarters facility at 700QO, together with its related finance lease obligation, certain related property and equipment and land parcel adjacent to the facility as held for sale, in accordance with its accounting policy defined in Note 2. The assets and liabilities of the Disposal Group were classified as held for sale and were presented separately in Current assets and Current liabilities on the consolidated balance sheet. In October 2025, the Company entered into an assignment of the lease with respect to the Disposal Group with AstraZeneca Pharmaceuticals LP (“AstraZeneca”). The effect of the agreement is to assign the lease agreement for 700QO, together with a parcel purchase agreement for the sale of a parcel of land adjacent to the 700QO facility and an asset purchase agreement for the sale of certain personal property and equipment, for an aggregate of $59.8 million payable by AstraZeneca to the Company. The fair value less cost to sell of the Disposal Group was $56.3 million, comprised of $59.8 million of sale

F- 37 consideration, less $3.5 million of costs to sell. The carrying value of the Disposal Group was determined to be greater than its fair value less costs to sell and, consequently, the Company recorded an impairment of assets held for sale of $97.8 million during the year ended December 31, 2025.

The initial net payment of $19.7 million related to the parcel purchase (land sale), was received in November 2025. The remaining $39.8 million payment was received in January 2026. The held for sale finance lease obligation of $47.9 million was derecognized on the assignment of the 700QO lease agreement in January 2026.

The other restructuring charge recorded by the Company consisted of the following (in thousands):

(1) Restructuring charges of $5.5 million and $7.1 million are included in Research and development and Selling, general, and administrative expenses, respectively, in the Company’s consolidated statement of operations in 2025. Restructuring charges of $1.0 million, $2.4 million and $13.6 million are included in Cost of sales, Research and development and Selling, general, and administrative expenses, respectively, in the consolidated statement of operations in 2024. Restructuring charges of $0.5 million, $2.3 million and $11.5 million are included in Cost of sales, Research and development and Selling, general, and administrative expenses, respectively, in the consolidated statement of operations in 2023. These charges reflect substantially all expected restructuring charges under the Restructuring Plan.

Severance and employee benefit costs

Employees affected by the reduction in force under the Restructuring Plan are entitled to receive severance payments and certain termination benefits. The Company recorded a severance and termination benefit cost in full for employees who were notified of their termination during the year ended December 31, 2025 and had no requirements for future service.

The following table summarizes the activity within the accrued severance and employee benefits liability, which is included in "Accrued expenses" in the Company’s consolidated balance sheets, for the years ended December 31, 2025, 2024, and 2023 (in thousands):

Impairment of long-lived assets

In connection with the Restructuring Plan, the Company also evaluated its long-lived assets, other than the Disposal Group classified as held for sale, for impairment. The Company performed an impairment evaluation for the applicable long-lived assets, which is subject to judgment and actual results may vary from the estimates, resulting in potential future adjustments to amounts recorded. During the year ended December 31, 2025, 2024 and 2023, the Company recorded an impairment charge of $4.9 million, $4.1 million and $10.1 million, respectively, related to the impairment of long-lived assets, including $5.9 million related to ROU assets for facility leases in 2023.

Note 20 –Disposition of Assets

In December 2024, Novavax CZ a.s. (“CZ”), a wholly-owned subsidiary of the Company, completed the sale of its biologics manufacturing campus located at Bohumil, Czech Republic (the “Facility”) to Novo Nordisk Production Czech s.r.o. (the “Purchaser”), pursuant to an asset purchase agreement, dated as of December 3, 2024 (the “Asset Purchase Agreement”). Under the Asset Purchase Agreement, CZ sold, transferred and assigned to the Purchaser: (i) land and properties that comprise

F- 38 the Facility, as well as certain moveable assets and equipment located at the Facility (the “Transferred Assets”); (ii) contracts related to the operation and management of the Transferred Assets (the “Transferred Contracts”); and (iii) certain employees providing services related to the Transferred Assets (the “Transferred Employees”).

The total purchase price for the sale was $202.6 million and the assumption by the Purchaser of liabilities (on a look-forward basis) pertaining to the Transferred Assets, Transferred Contracts and Transferred Employees. On the closing date, the Company received a cash payment of $180 million, net of the initial payment of $10 million made in October 2024 and $10 million placed in an escrow account released to the Company in 2025 following the closing date (subject to adjustment for any claims the Purchaser may have against the Seller under the Asset Purchase Agreement). Pursuant to the terms of the Asset Purchase Agreement, the Company was also reimbursed $2.6 million, subject to adjustments, for costs incurred in continuing to operate and maintain the Transferred Assets, Transferred Contracts and Transferred Employees between December 3, 2024 and the completion of the sale.

The Company recognized a gain on the sale of $51.9 million, which has been reflected in Other income in the Company's consolidated statement of operations for the year ended December 31, 2024. The disposition qualified as the sale of a business pursuant to ASC Topic 805, Business Combinations, and therefore, the Company allocation goodwill of $12.4 million to the sale on a relative fair value basis.

Note 21 –Segment Reporting

The Company manages its business asone reportable operating segment, an in-house early-stage R&D business to build a pipeline of high-value assets using its proven technology along with seeking to enter into partnerships to drive value creation for its assets. The Company has determined its reportable operating segment based on the management approach, which considers the internal organization and reporting used by the Company’s CODM to make decisions about allocating resources and assessing the Company’s performance. The Company’s CODM uses consolidated single-segment net loss as reported in the consolidated statements of operations to evaluate performance, forecast future period financial results, allocate resources, and set incentive targets.

The table below summarizes the significant expense categories regularly reviewed by the CODM (in thousands):

(1) Direct research and development expenses are comprised primarily of costs paid to third parties for clinical and product development activities. Direct coronavirus vaccines expenses include costs associated with the Phase 3 trial for the Company’s CIC and stand-alone influenza vaccine candidates.

(2) Facility and other research and development expenses consist of indirect costs incurred in support of overall research and development activities and non-specific programs, such as overhead costs, information technology and facility-based expenses not allocated to a specific program.

(3) Other segment income (expense) includes interest expense, impairment of assets held for sale, loss on debt extinguishment, gain on disposition of Novavax CZ assets, income tax expense (benefit), and other income, net.

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Total revenue by the Company’s customer’s or collaboration partner’s geographic location was as follows (in thousands):

Total long-lived assets of the Company by geographic location were as follows (in thousands):

Note 22 –Subsequent Events

In January 2026, the Company successfully completed the assignment of its leasehold interest in 700QO and sale of certain related property and equipment and received $39.8 million of the remaining consideration from AstraZeneca (Note 19). In connection with this closing, the Company was legally relieved of its primary obligation under the lease. The ROU asset and the related lease liability, classified as held for sale as of December 31, 2025, was derecognized from the consolidated balance sheet in the first quarter of 2026. No additional impairment adjustments are anticipated as a result of the closing of this transaction.

In January 2026, the Company entered into a License and Option Agreement with Pfizer Inc. (“Pfizer”) for use of the Company’s Matrix-M™. Under the terms of the agreement, Pfizer will obtain a non-exclusive license for Matrix-M™ for use with Pfizer's products in up totwo disease areas. The agreement provides for an upfront payment of $30 million, which was received in January 2026, and the Company has the potential to receive up to $500 million in development and sales milestone payments. In addition to milestone payments, the Company is eligible to receive tiered high mid-single digit percentage royalty payments on sales of any product by Pfizer that includes Matrix-M™.

In February 2026, the Company entered into a Credit, Security, and Guaranty Agreement (the “Credit Agreement”) with MidCap Financial Trust, as administrative agent. The Credit Agreement provides for a senior secured term loan facility of up to $330 million, available infour tranches. The first tranche of $130 million, of which $50 million was funded at closing, is available to be drawn, subject to customary conditions, through February 2028. Borrowings under the Credit Agreement bear interest, payable monthly in arrears, at a rate per annum equal to the secured overnight financing rate (“Term SOFR”) plus 5.00%, subject to a Term SOFR floor of 2.00%. The term loans mature in March 2031, at which time all outstanding principal and accrued interest are due and payable in full.

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