Vaxart, Inc.

Previous wording

In June 2025, we reported positive topline results from a Phase 1 clinical trial (Study VXA-109) evaluating our second-generation bivalent norovirus vaccine constructs head-to-head against our first-generation bivalent norovirus vaccine constructs. The open-label, Phase 1 trial was conducted in 60 healthy volunteers who were randomized to receive the first-generation vaccine constructs, an equivalent dose of the second-generation GI.1 and GII.4 vaccine constructs, or a lower dose of the second-generation vaccine constructs (n=20 for each group). The primary immunological endpoint was norovirus blocking antibody assay (NBAA) titer at Day 0 and Day 28. In a Phase 2 challenge study of the first-generation vaccine constructs, these functional NBAA titers were identified as correlates of protection against norovirus infection. Although the study was not powered to determine superiority by statistical methods, the increase in NBAA titers with the second-generation vaccine candidates was sufficiently large (141% for the GI.1 vaccine candidate and 94% for the GII.4 vaccine candidate) to demonstrate statistical significance at the equivalent dose. Further support for the second-generation bivalent norovirus vaccine was provided by the fecal IgA data from the VXA-109 Study. The data showed a 25-fold increase in the GII.4 fecal IgA response and a 10-fold increase in the GI.1 fecal IgA response over baseline with the high dose of the second-generation vaccine candidates after a single tablet administration for each strain. The data also showed an 8-fold increase in the GII.4 fecal IgA response and a 7-fold increase in the GI.1 fecal IgA response over baseline with the low dose of the second-generation vaccine candidates after a single tablet administration for each strain. While the Phase 1 study was not powered to determine superiority by statistical methods, the fecal IgA increases observed with the second-generation constructs compared favorably to the increases observed with the first-generation constructs at the same high dose level and in the same study (13-fold GII.4 and 6-fold GI.1 over baseline).

Current wording

In June 2025, we reported positive topline results from a Phase 1 clinical trial (Study VXA-109) evaluating our second-generation bivalent norovirus vaccine constructs head-to-head against our first-generation bivalent norovirus vaccine constructs. The open-label, Phase 1 trial was conducted in 60 healthy volunteers who were randomized to receive the first-generation vaccine constructs, an equivalent dose of the second-generation GI.1 and GII.4 vaccine constructs, or a lower dose of the second-generation vaccine constructs (n=20 for each group). The primary immunological endpoint was norovirus blocking antibody assay (NBAA) titer at Day 0 and Day 28. In a Phase 2 challenge study of the first-generation vaccine constructs, these functional NBAA titers were identified as correlates of protection against norovirus infection. Although the study was not powered to determine superiority by statistical methods, the increase in NBAA titers with the second-generation vaccine candidates was sufficiently large (164% for the GI.1 vaccine candidate and 114% for the GII.4 vaccine candidate) to demonstrate statistical significance at the equivalent dose. Further support for the second-generation bivalent norovirus vaccine was provided by the fecal IgA data from the VXA-109 Study. The data showed a 25-fold increase in the GII.4 fecal IgA response and a 10-fold increase in the GI.1 fecal IgA response over baseline with the high dose of the second-generation vaccine candidates after a single tablet administration for each strain. The data also showed an 8-fold increase in the GII.4 fecal IgA response and a 7-fold increase in the GI.1 fecal IgA response over baseline with the low dose of the second-generation vaccine candidates after a single tablet administration for each strain. While the Phase 1 study was not powered to determine superiority by statistical methods, the fecal IgA increases observed with the second-generation constructs compared favorably to the increases observed with the first-generation constructs at the same high dose level and in the same study (13-fold GII.4 and 6-fold GI.1 over baseline).

Previous wording

In June 2024, we entered into an agreement (as modified or amended from time to time, the “2024 ATI-RRPV Contract”) with Advanced Technology International (“ATI”), the Rapid Response Partnership Vehicle’s Consortium Management Firm funded by HHS BARDA for a Phase 2b clinical study. This Phase 2b clinical study is designed as a double-blind, multi-center, randomized, comparator-controlled study to determine the relative efficacy, safety, and immunogenicity of Vaxart’s oral pill COVID-19 vaccine candidate against an approved mRNA COVID-19 injectable vaccine in adults previously immunized against COVID-19 infection. The 2024 ATI-RRPV Contract initially provided for funding of up to $460.7 million to conduct this Phase 2b study, manufacture a COVID-19 vaccine candidate, and acquire an approved mRNA vaccine targeting a homologous strain.

Current wording

In June 2024, we entered into an agreement (as modified or amended from time to time, the “2024 ATI-RRPV Contract”) with Advanced Technology International (“ATI”), the Rapid Response Partnership Vehicle’s Consortium Management Firm funded by HHS BARDA for a Phase 2b clinical study. This Phase 2b clinical study is designed as a double-blind, multi-center, randomized, comparator-controlled study to determine the relative efficacy, safety, and immunogenicity of Vaxart’s oral pill COVID-19 vaccine candidate against an approved mRNA COVID-19 injectable vaccine in adults previously immunized against COVID-19 infection. The 2024 ATI-RRPV Contract initially authorized to receive total funding of up to $460.7 million to conduct this Phase 2b study, manufacture a COVID-19 vaccine candidate, and acquire an approved mRNA vaccine targeting a homologous strain.

Previous wording

In the second half of 2024, we initiated and completed enrollment of the 400-participant sentinel cohort of our Phase 2b study comparing our XBB COVID-19 vaccine candidate to an approved mRNA XBB comparator, and in January 2025 the independent data safety monitoring board recommended the study proceed without modifications based on 30-day sentinel cohort data, with 12-month follow-up data expected in the first half of 2026. Following a February 2025 ATI stop work order on the 2024 ATI-RRPV Contract (lifted in April 2025), we received HHS BARDA approval in May 2025 to initiate dosing in the 10,000-participant main cohort of the Phase 2b study; however, in August 2025 ATI issued a second stop work order halting further screening and enrollment after approximately half of the targeted participants had been enrolled, and on October 8, 2025, ATI issued a Follow-Up Notice confirming BARDA’s intent to stop all ongoing enrollment under the contract while permitting continued follow-up and planned analyses of the sentinel and enrolled main study populations, with contract funding currently under review and likely to be reduced commensurate with the reduced enrollment.

Current wording

In the second half of 2024, we initiated and completed enrollment of the 400-participant sentinel cohort of our Phase 2b study comparing our XBB COVID-19 vaccine candidate to an approved mRNA XBB comparator, and in January 2025 the independent data safety monitoring board recommended the study proceed without modifications based on 30-day sentinel cohort data. Following a February 2025 ATI stop work order on the 2024 ATI-RRPV Contract (lifted in April 2025), we received HHS BARDA approval in May 2025 to initiate dosing in the 10,000-participant main cohort of the Phase 2b study; however, in August 2025 ATI issued a second stop work order halting further screening and enrollment after approximately half of the targeted participants had been enrolled, and on October 8, 2025, ATI issued a Follow-Up Notice confirming BARDA’s intent to stop all ongoing enrollment under the contract while permitting continued follow-up and planned analyses of the sentinel and enrolled main study populations.

Previous wording

In connection with these contract developments, the Company has received funding through a series of contract modifications tied to authorized milestones. Pursuant to Modification No. 6 to the 2024 ATI-RRPV Contract, dated March 10, 2026 (the most recent contract modification), the total amount of funding available for payment under the 2024 ATI-RRPV Contract is approximately $316.0 million, including $67.9 million of firm fixed price amounts and the remaining amount for reimbursement of costs incurred in trial preparation and execution activities. The Company anticipates a further modification to the 2024 ATI-RRPV Contract reflecting the reduced scope of work and corresponding reduction in funding resulting from the previously issued stop work orders that halted enrollment and reduced the size of the study. Notwithstanding these adjustments, the parties have reached agreement on the continuing scope of work.

Current wording

In connection with these contract developments, the Company has received funding through a series of contract modifications tied to authorized milestones. The Company most recently signed Modification No. 7 to the 2024 ATI-RRPV Contract, dated June 22, 2026, which adjusted the total amount of authorized funding under the 2024 ATI-RRPV contract to approximately $344.8 million, including $67.9 million of firm fixed price amounts and the remaining amount for reimbursement of costs incurred in trial preparation and execution activities. The funding available for payment increased from $316.0 million to $331.0 million (an increase of $15.0 million) as compared to the previous Modification No. 6 signed March 10, 2026. The June 2026 total authorized funding reduction from $460.7 million to $344.8 million in the 2024 ATI-RRPV Contract reflected reduction in scope of work and corresponding reduction in funding that resulted from previously issued stop work orders that halted enrollment and therefore reduced the size of the study.

Previous wording

Based on our understanding of the currently agreed scope, we anticipate that the Phase 2b study, which enrolled healthy adults 18 years and older in the U.S. with 400 participants from the sentinel cohort and approximately 5,000 participants enrolled from the main cohort as of our receipt of the August stop work order, will continue to collect participant data over a 12 month period post-vaccination and will continue to be funded under the 2024 ATI-RRPV Contract. Out of the approximately 5,400 total participants, we expect approximately 2,700 to have received our COVID-19 vaccine candidate and approximately 2,700 to have received an approved strain-matched mRNA comparator. The study has been conducted to enroll participants in line with U.S. demographics, as well as to include at least 25% over the age of 65.

Current wording

Based on the currently agreed scope, we anticipate that the Phase 2b study, which enrolled healthy adults 18 years and older in the U.S. with 400 participants from the sentinel cohort and approximately 5,000 participants enrolled from the main cohort as of our receipt of the August 5, 2025 stop work order, will continue to collect participant data over a 12 month period post-vaccination and will continue to be funded under the 2024 ATI-RRPV Contract. Out of the approximately 5,400 total participants, we expect approximately 2,700 to have received our COVID-19 vaccine candidate and approximately 2,700 to have received an approved strain-matched mRNA comparator. The study has been conducted to enroll participants in line with U.S. demographics, as well as to include at least 25% over the age of 65.

Previous wording

In June 2024, we entered into the 2024 ATI-RRPV Contract. In the second half of 2024, the 2024 ATI-RRPV Contract was modified to increase funding and expand the scope to include the manufacture of a vaccine candidate targeting the KP.2 strain and acquire an approved mRNA vaccine targeting the KP.2 strain. Pursuant to the 2024 ATI-RRPV Contract (as modified or amended from time to time), we were to receive overall funding of up to $460.7 million to conduct a Phase 2b comparative study evaluating our oral pill COVID-19 vaccine candidate against an mRNA vaccine comparator approved by the FDA. Funding has been release pursuant to authorized milestones delineated in a series of contract modifications. Pursuant to Modification No. 6 to the 2024 ATI-RRPV Contract, dated March 10, 2026 (the most recent contract modification), the total amount of funding available for payment under the 2024 ATI-RRPV Contract is approximately $316.0 million, including $67.9 million of firm fixed price amounts and the remaining amount for reimbursement of costs incurred in trial preparation and execution activities. The Company anticipates a further modification to the 2024 ATI-RRPV Contract that will reflect the reduced scope of work and corresponding reduction in funding that resulted from previously issued stop work order that halted enrollment and therefore reduced the size of the study. Revenue from government contracts recognized on the 2024 ATI-RRPV Contract was $36.4 million and $19.3 million for the three months ended March 31, 2026 and 2025, respectively, based on costs incurred and the achievement of firm fixed-price milestones under the 2024 ATI-RRPV Contract. For further information about the August 5, 2025 stop work order relating to the 2024 ATI-RRPV Contract, see the section above titled “—Our Product Pipeline” in the “Coronavirus Vaccine” discussion.

Current wording

In June 2024, we entered into the 2024 ATI-RRPV Contract. In the second half of 2024, the 2024 ATI-RRPV Contract was modified to increase funding and expand the scope to include the manufacture of a vaccine candidate targeting the KP.2 strain and acquire an approved mRNA vaccine targeting the KP.2 strain. Pursuant to the 2024 ATI-RRPV Contract (as modified or amended from time to time), we were to receive total funding of up to $460.7 million to conduct a Phase 2b comparative study evaluating our oral pill COVID-19 vaccine candidate against an mRNA vaccine comparator approved by the FDA. Funding has been released pursuant to authorized milestones delineated in a series of contract modifications. The Company most recently signed Modification No. 7 to the 2024 ATI-RRPV Contract, dated June 22, 2026, which increased the total amount of funding available for payment under the 2024 ATI-RRPV Contract to approximately $331.0 million, an increase of approximately $15.0 million as compared to the approximately $316.0 million funding authorized for payment under Modification No. 6, dated March 10, 2026. The authorized total funding in Modification No. 7 was reduced at the same time by $115.9 million to $344.8 million as compared to $460.7 million previously, to reflect the reduced scope of work from the previously issued stop work orders that halted enrollment and reduced the size of the study. Revenue from government contracts recognized on the 2024 ATI-RRPV Contract was $24.3 million and $39.7 million for the three months ended June 30, 2026 and 2025, respectively, based on costs incurred and the achievement of firm fixed-price milestones under the 2024 ATI-RRPV Contract. For further information about the August 5, 2025 stop work order relating to the 2024 ATI-RRPV Contract, see the section above titled “—Our Product Pipeline” in the “Coronavirus Vaccine” discussion.

Previous wording

The following table shows our period-over-period research and development expenses, identifying external costs that were incurred in each of our vaccine programs and, separately, on preclinical research and process development for the three months ended March 31, 2026 and 2025 (in thousands):

Current wording

The following table shows our period-over-period research and development expenses, identifying external costs that were incurred in each of our vaccine programs and, separately, on preclinical research and process development for the three and six months ended June 30, 2026 and 2025 (in thousands):

Previous wording

The following table presents period-over-period changes in selected items in the condensed consolidated statements of operations and comprehensive loss for the three months ended March 31, 2026 and 2025 (in thousands, except percentages):

Current wording

The following table presents period-over-period changes in selected items in the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2026 and 2025 (in thousands, except percentages):

Previous wording

The following table summarizes the period-over-period changes in our revenues for the three months ended March 31, 2026 and 2025 (in thousands, except percentages):

Current wording

The following table summarizes the period-over-period changes in our revenues for the three and six months ended June 30, 2026 and 2025 (in thousands, except percentages):

Previous wording

For the three months ended March 31, 2026 and 2025, non-cash royalty revenue related to sale of future royalties from Daiichi Sankyo was $42,000 and $1.6 million, respectively. We continue to have non-cash royalty revenue as all royalties received for the three months ended March 31, 2026 and 2025 were required to be paid to HCRP.

Current wording

For the three and six months ended June 30, 2026 and 2025, non-cash royalty revenue related to sale of future royalties from Daiichi Sankyo was $11,000 and zero, and $53,000 and $1.6 million, respectively. We continue to have non-cash royalty revenue as all royalties received for the three and six months ended June 30, 2026 and 2025 were required to be paid to HCRP.

Previous wording

For the three months ended March 31, 2026 and 2025, revenue from government contracts was $36.4 million and $19.3 million, respectively. The revenue from government contracts consists of the 2024 ASPR-BARDA Contract awarded to us in January 2024 and the 2024 ATI-RRPV Contract awarded to us in June 2024. No revenue was recognized under the 2024 ASPR-BARDA Contract for the three months ended March 31, 2026 and 2025, respectively. Revenue from the 2024 ATI-RRPV Contract was $36.4 million and $19.3 million for the three months ended March 31, 2026 and 2025, respectively.

Current wording

For the three and six months ended June 30, 2026 and 2025, revenue from government contracts was $24.3 million and $39.7 million, and $60.6 million and $59.0 million, respectively. The revenue from government contracts consists of the 2024 ASPR-BARDA Contract awarded to us in January 2024 and the 2024 ATI-RRPV Contract awarded to us in June 2024. No revenue was recognized under the 2024 ASPR-BARDA Contract for the three and six months ended June 30, 2026 and 2025, respectively. Revenue from the ATI-RRPV Contract was $24.3 million and $39.7 million for the three months ended June 30, 2026 and 2025, respectively, and $60.6 million and $59.0 million for the six months ended June 30, 2026 and 2025, respectively.

Previous wording

For the three months ended March 31, 2026 and 2025, collaboration revenue was $2.8 million, compared to zero for both license and collaboration revenue for the three months ended March 31, 2025. The license and collaboration revenue derives from the 2025 License and Collaboration Agreement signed in November 2025. Revenue recognized in 2026 primarily relates to the portion of the upfront consideration allocated to development activities performed during the period.

Current wording

For the three and six months ended June 30, 2026 and 2025, collaboration revenue was $2.9 million and zero, and $5.7 million and zero, respectively. The license and collaboration revenue derives from the 2025 License and Collaboration Agreement signed in November 2025. Revenue recognized in 2026 primarily relates to the portion of the upfront consideration allocated to development activities performed during the period.

Previous wording

The following table summarizes the period-over-period changes in our operating expenses for the three months ended March 31, 2026 and 2025 (in thousands, except percentages):

Current wording

The following table summarizes the period-over-period changes in our operating expenses for the three and six months ended June 30, 2026 and 2025 (in thousands, except percentages):

Previous wording

For the three months ended March 31, 2026, research and development expenses decreased by $1.3 million, or 4%, compared to the three months ended March 31, 2025. The net decrease was primarily due to a decrease in personnel, preclinical and manufacturing costs, partially offset by an increase in clinical trial expenses related to our COVID-19 vaccine candidate.

Current wording

For the three months ended June 30, 2026, research and development expenses decreased by $16.0 million, or 32%, compared to the three months ended June 30, 2025. The net decrease was primarily due to a decrease in clinical trial expenses related to our COVID-19 vaccine candidate, personnel costs, facilities costs, and preclinical and manufacturing costs.

Previous wording

For the three months ended March 31, 2026, general and administrative expenses decreased by $0.4 million, or 8%, compared to the three months ended March 31, 2025. The net decrease was primarily due to a decrease in personnel, facilities and recruiting costs, partially offset by an increase in professional and legal fees.

Current wording

For the three months ended June 30, 2026, general and administrative expenses increased by $2.0 million, or 44%, compared to the three months ended June 30, 2025. The net increase was primarily due to an increase in professional and legal fees partially offset by a decrease in personnel costs.

Previous wording

The following table summarizes the period-over-period changes in our non-operating income for the three months ended March 31, 2026 and 2025 (in thousands, except percentages):

Current wording

The following table summarizes the period-over-period changes in our non-operating income for the three and six months ended June 30, 2026 and 2025 (in thousands, except percentages):

Previous wording

For thethree months ended March 31, 2026, we recorded interest income of $0.6 million, a 26% increase from the $0.4 million interest income recorded in thethree months ended March 31, 2025. The increase is primarily due to the increase in our cash, cash equivalents and investments balance.

Current wording

For thethree months ended June 30, 2026, we recorded interest income of $0.6 million, an 86% increase from the $0.3 million interest income recorded in thethree months ended June 30, 2025. For thesix months ended June 30, 2026, we recorded interest income of $1.1 million, a 51% increase from the $0.7 million interest income recorded in thesix months ended June 30, 2025. The increase is due to both higher average cash, cash equivalents and short-term investment balances held and more favorable interest rates available.

Previous wording

Non-cash interest expense related to sale of future royalties representing imputed interest on the unamortized portion of the sale of future royalties liability, was $0.5 million for the three months ended March 31, 2026, with $1.0 million for the three months ended March 31, 2025 due to a decrease in non-cash royalty revenue payable to HCRP.

Current wording

Non-cash interest expense related to sale of future royalties representing imputed interest on the unamortized portion of the sale of future royalties liability, was $0.5 million and $0.7 million for the three months ended June 30, 2026 and 2025 and $1.0 million and $1.7 million for the six months ended June 30, 2026 and 2025. The decrease was due to a decrease in non-cash royalty revenue payable to HCRP.

Previous wording

The following table summarizes the period-over-period changes in our provision for income taxes for the three months ended March 31, 2026 and 2025 (in thousands, except percentages):

Current wording

The following table summarizes the period-over-period changes in our provision for income taxes for the three and six months ended June 30, 2026 and 2025 (in thousands, except percentages):

Previous wording

The provision for income taxes was $29,000 and $95,000 for the three months ended March 31, 2026 and 2025, respectively. The tax charge relates to foreign tax expense attributable to interest on an intercompany loan from a foreign subsidiary, and a 5% withholding tax on royalty revenue earned on sales of Inavir in Japan, which is potentially recoverable as a foreign tax credit but expensed because we record a 100% valuation allowance against our deferred tax assets. The amount of foreign withholding tax expense recorded is directly proportional to Inavir royalties, including the portion that we pass through to HCRP.

Current wording

The provision for income taxes was $29,000 and $20,000 for the three months ended June 30, 2026 and 2025, respectively and $58,000 and $115,000 for the six months ended June 30, 2026 and 2025, respectively. The tax charge relates to foreign tax expense attributable to interest on an intercompany loan from a foreign subsidiary, and a 5% withholding tax on royalty revenue earned on sales of Inavir in Japan, which is potentially recoverable as a foreign tax credit but expensed because we record a 100% valuation allowance against our deferred tax assets. The amount of foreign withholding tax expense recorded is directly proportional to Inavir royalties, including the portion that we pass through to HCRP.

Previous wording

In June 2024, we entered into the 2024 ATI-RRPV Contract. Pursuant to the 2024 ATI-RRPV Contract, we were authorized to receive overall funding of up to $460.7 million to conduct a Phase 2b comparative study evaluating our oral pill COVID-19 vaccine candidate against an mRNA vaccine comparator approved by the U.S. Food and Drug Administration, manufacture a COVID-19 vaccine candidate targeting the KP.2 strain, and acquire an approved mRNA vaccine targeting the KP.2 strain. As of March 31, 2026, we have received $218.9 million of cash payments under the 2024 ATI-RRPV Contract. Subsequent to March 31, 2026, through the filing date of this Quarterly Report on Form 10-Q, we have received $19.8 million under the 2024 ATI-RRPV Contract. On August 5, 2025, the Company received written notification from ATI in the form of a stop work order directing the Company to stop work on screening and enrollment for the COVID-19 Phase 2b trial under the 2024 ATI-RRPV Contract as of the notification date. On October 8, 2025, the Company received a follow-up notice from ATI, which indicated that BARDA intends to conclusively exclude work subject to the foregoing stop work order from the 2024 ATI-RRPV Contract. The Company was, however, authorized to continue efforts associated with the per protocol follow-up of all participants dosed as of the notification date in the study under the terms of the 2024 ATI-RRPV Contract. When the Company received the August notification, we had enrolled approximately half of the targeted number of participants for the study. On March 10, 2026, we entered into Modification No. 6 to the 2024 ATI-RRPV Contract, which increased the total amount of funding available for payment to approximately $316.0 million. The Company anticipates a further modification to the 2024 ATI-RRPV Contract that will reflect the reduced scope of work and corresponding reduction in funding that resulted from previously issued stop work orders that halted enrollment and therefore reduced the size of the study.

Current wording

In June 2024, we entered into the 2024 ATI-RRPV Contract. Pursuant to the 2024 ATI-RRPV Contract, we were authorized to receive total funding of up to $460.7 million to conduct a Phase 2b comparative study evaluating our oral pill COVID-19 vaccine candidate against an mRNA vaccine comparator approved by the U.S. Food and Drug Administration, manufacture a COVID-19 vaccine candidate targeting the KP.2 strain, and acquire an approved mRNA vaccine targeting the KP.2 strain. As of June 30, 2026, we have received $253.8 million of cash payments under the 2024 ATI-RRPV Contract. Subsequent to June 30, 2026, through the filing date of this Quarterly Report on Form 10-Q, we have received $12.8 million under the 2024 ATI-RRPV Contract. On August 5, 2025, the Company received written notification from ATI in the form of a stop work order directing the Company to stop work on screening and enrollment for the COVID-19 Phase 2b trial under the 2024 ATI-RRPV Contract as of the notification date. On October 8, 2025, the Company received a follow-up notice from ATI, which indicated that BARDA intends to conclusively exclude work subject to the foregoing stop work order from the 2024 ATI-RRPV Contract. The Company was, however, authorized to continue efforts associated with the per protocol follow-up of all participants dosed as of the notification date in the study under the terms of the 2024 ATI-RRPV Contract. When the Company received the August notification, we had enrolled approximately half of the targeted number of participants for the study. The Company most recently signed Modification No. 7 to the 2024 ATI-RRPV Contract, dated June 22, 2026, which adjusted the total amount of authorized funding under the 2024 ATI-RRPV Contract down to approximately $344.8 million, including $67.9 million of firm fixed price amounts and the remaining amount for reimbursement of costs incurred in trial preparation and execution activities. The funding available for payment increased from $316.0 million to $331.0 million (an increase of $15.0 million) as compared to the previous Modification No. 6 signed March 10, 2026. The 2024 ATI-RRPV Contract further contemplates additional funding up to $13.8 million if the Company and HHS BARDA decide to continue with the Phase 2b comparative study. The June 2026 reduction from $460.7 million to $344.8 million in the 2024 ATI-RRPV Contract reflected reduction in scope of work and corresponding reduction in funding that resulted from previously issued stop work orders that halted enrollment and therefore reduced the size of the study.

Previous wording

Effective July 8, 2025, Nasdaq suspended trading in our common stock and the Company was formally delisted from Nasdaq following a final determination by the Nasdaq's Listing Qualifications Department on November 3, 2025. Our common stock has been quoted on the OTCQX under the ticker symbol “VXRT” since the stock was suspended from trading on Nasdaq on July 8, 2025. The National Securities Markets Improvement Act of 1996 prevents or preempts the states from regulating the sale of certain securities, which are referred to as “covered securities.” As Nasdaq has officially delisted our securities, our securities are not covered securities since OTCQX-traded securities are not considered covered securities, and we will need to follow each state’s blue sky laws for offers and sales of our securities made to residents of that state. This state-level regulation introduces additional compliance requirements for brokers to consider when trading in our securities and will further negatively impact any trading liquidity in our securities.

Current wording

Effective July 8, 2025, Nasdaq suspended trading in our common stock and the Company was formally delisted from Nasdaq effective December 1, 2025. Our common stock has been quoted on the OTCQX under the ticker symbol “VXRT” since the stock was suspended from trading on Nasdaq on July 8, 2025. The National Securities Markets Improvement Act of 1996 prevents or preempts the states from regulating the sale of certain securities, which are referred to as “covered securities.” As Nasdaq has officially delisted our securities, our securities are not covered securities since OTCQX-traded securities are not considered covered securities, and we will need to follow each state’s blue sky laws for offers and sales of our securities made to residents of that state. This state-level regulation introduces additional compliance requirements for brokers to consider when trading in our securities and will further negatively impact any trading liquidity in our securities.

Previous wording

In April 2026, the Company entered into a purchase agreement (the “April 2026 ELOC”) with Lincoln Park Capital Fund, LLC (“LPC”), pursuant to which the Company may sell, from time to time, shares of its common stock having an aggregate offering price of up to $25.0 million (the “Commitment Amount”), subject to certain limitations and conditions. The Company intends to file a registration statement with the SEC covering the resale by LPC of the Purchase Shares that have been and may be issued to LPC under the April 2026 ELOC.

Current wording

In April 2026, we entered into a purchase agreement (the “April 2026 ELOC”) with Lincoln Park Capital Fund, LLC (“LPC”), pursuant to which the Company may sell, from time to time, up to $25.0 million (the “Commitment Amount”) of registered shares of its common stock over a 24-month period, subject to certain limitations and conditions. In May 2026, the Company filed a registration statement with the SEC covering the resale by LPC of the Purchase Shares that have been and may be issued to LPC under the April 2026 ELOC. As of June 30, 2026, 75,000 shares were issued and sold under the April 2026 ELOC for gross proceeds of $44,000. As of June 30, 2026, approximately $25 million of the Commitment Amount remained available for issuance and sale pursuant to the April 2026 ELOC.

Previous wording

As of March 31, 2026, we had approximately $61.0 million of cash, cash equivalents and short-term investments. Our cash, cash equivalents and investments are sufficient to fund our planned operations for at least the period of 12 months from the date of issuance of this Quarterly Report. To continue operations, we expect that we will need to raise further capital, through the sale of additional securities or otherwise; however, adequate funding may not be available to us on acceptable terms, or at all, particularly in light of current economic uncertainty, high interest rates, rising inflation, tariffs, and the potential for local and/or global economic recession. Our future capital requirements and the adequacy of our available funds will depend on many factors, most notably our ability to successfully commercialize our products and services.

Current wording

As of June 30, 2026, we had approximately $64.0 million of cash, cash equivalents and short-term investments. Our cash, cash equivalents and investments are sufficient to fund our planned operations for at least the period of 12 months from the date of issuance of this Quarterly Report. To continue operations, we expect that we will need to raise further capital, through the sale of additional securities or otherwise; however, adequate funding may not be available to us on acceptable terms, or at all, particularly in light of current economic uncertainty, high interest rates, rising inflation, tariffs, and the potential for local and/or global economic recession. Our future capital requirements and the adequacy of our available funds will depend on many factors, most notably our ability to successfully commercialize our products and services.

Previous wording

Based on management’s current plan, which reflects updated assumptions based on events occurring after March 31, 2026, we expect to have cash runway into the second quarter of 2027. See Note 13 to the Condensed Consolidated Financial Statements in Part I, Item 1 for further details. Accordingly, management concluded that the conditions and events that previously raised substantial doubt about our ability to continue as a going concern have been alleviated. The accompanying consolidated financial statements have been prepared assuming that we will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business.

Current wording

Based on management’s current plan, we expect to have enough cash runway into the second quarter of 2027. If we are unable to raise additional capital in sufficient amounts or on acceptable terms, management’s plans include further reducing or delaying operating expenses. These conditions raise substantial doubt about our ability to continue as a going concern for a period of one year from the date of the issuance of these consolidated financial statements. The accompanying consolidated financial statements have been prepared assuming that we will continue as a going concern, which contemplates the realization of assets and the settlement of liabilities and commitments in the normal course of business.

Previous wording

Net Cash Used in Operating Activities

Current wording

Net Cash Provided by (Used in) Operating Activities

Previous wording

We experienced negative cash flow from operating activities for the three months ended March 31, 2026 and 2025, in the amounts of $2.1 million and $9.6 million, respectively. The cash used in operating activities in the three months ended March 31, 2026, was driven by net income of $5.2 million, partially offset by an increase in working capital of $10.0 million (consisting of an increase in receivables from government contracts and accounts payable and partially offset by a decrease in accrued labilities, accounts receivable, and prepaid expenses), and adjustments for net non-cash expenses related to depreciation and amortization, accretion of discount on investments, net, stock-based compensation, non-cash interest expense related to sale of future royalties and non-cash revenue related to sale of future royalties totaling $2.7 million. The cash used in operating activities in the three months ended March 31, 2025, was due to cash used to fund a net loss of $15.6 million, partially offset by a decrease in working capital of $3.4 million, and adjustments for net non-cash expenses related to depreciation and amortization, accretion of discount on investments, net, stock-based compensation, non-cash interest expense related to sale of future royalties and non-cash revenue related to sale of future royalties totaling $2.6 million.

Current wording

For operating activities, we experienced positive cash flow of $0.7 million for the six months ended June 30, 2026 and a negative cash flow of $25.5 million for the six months ended June 30, 2025. The net cash provided by operating activities in the six months ended June 30, 2026, was due to an operating net loss of $8.3 million, offset by an increase in working capital of $3.3 million (consisting of a decrease in receivables from government contracts and prepaid expenses and partially offset by an increase in unbilled receivables from government contracts, accounts payable, deferred collaboration revenue and accrued labilities), and adjustments for non-cash expenses related to stock-based compensation of $2.8 million, depreciation and amortization of $1.9 million, and $1.0 million of non-cash interest expense related to sale of future royalties. The cash used in operating activities in the six months ended June 30, 2025, was due to cash used to fund a net loss of $30.6 million, partially offset by a decrease in working capital of $1.0 million, and adjustments for net non-cash expenses related to depreciation and amortization, accretion of discount on investments, net, stock-based compensation, non-cash interest expense related to sale of future royalties and non-cash revenue related to sale of future royalties totaling $6.0 million.

Previous wording

In the three months ended March 31, 2026, we purchased $0.2 million of investments, net of maturities, and used $0.2 million to purchase property and equipment, net of proceeds. In the three months ended March 31, 2025, we received $13.4 million from maturities of investments, net of purchases, and used $0.1 million of cash to purchase property and equipment.

Current wording

In the six months ended June 30, 2026, we had $3.4 net cash used for investing activities. Net cash used resulted from $2.9 million of investments purchased, net of maturities, and used $0.5 million to purchase property and equipment, net of proceeds. In the six months ended June 30, 2025, we received $20.5 million from maturities of investments, net of purchases of investments.

Previous wording

In the three months ended March 31, 2026, we used $0.3 million to acquire common stock to settle employee tax withholding liabilities. In the three months ended March 31, 2025, we used $0.2 million to acquire common stock to settle employee tax withholding liabilities.

Current wording

In the six months ended June 30, 2026, we used $0.4 million to acquire common stock to settle employee tax withholding liabilities. In the six months ended June 30, 2025, we used approximately $0.2 million to acquire common stock to settle employee tax withholding liabilities.

Previous wording

As previously disclosed, in December 2025, the Company entered into a termination agreement (the “Termination Agreement”) with another landlord (the “Harbor Way Landlord”) in connection with the termination of that certain lease agreement (the “Harbor Way Lease”) for certain premises located at 170 Harbor Way, South San Francisco, California 94080 that served as the Company’s headquarters. The Harbor Way Lease consists of approximately 24,606 square feet of rentable space. Pursuant to the Termination Agreement, the Company and the Harbor Way Landlord agreed to terminate the Harbor Way Lease effective as of May 15, 2026.

Current wording

As previously disclosed, in December 2025, the Company entered into a termination agreement (the “Termination Agreement”) with another landlord (the “Harbor Way Landlord”) in connection with the termination of that certain lease agreement (the “Harbor Way Lease”) for certain premises located at 170 Harbor Way, South San Francisco, California 94080 that served as the Company’s headquarters. The Harbor Way Lease consisted of approximately 24,606 square feet of rentable space. Pursuant to the Termination Agreement, the Company and the Harbor Way Landlord terminated the Harbor Way Lease effective as of May 15, 2026.

Previous wording

Purchase obligations. As of March 31, 2026, the Company had approximately $19.3 million of non-cancelable purchase commitments, principally for clinical services which are expected to be paid within the next year. Approximately $18.2 million of non-cancelable purchase commitments are attributable to a third-party vendor that provides clinical services, that is reimbursable at approximately $19.6 million under a cost-plus-fixed-fees arrangement in the ATI-RRPV Contract.

Current wording

Purchase obligations. As of June 30, 2026, the Company had approximately $22.5 million of non-cancelable purchase commitments, principally for clinical services which are expected to be paid within the next year. Approximately $7.2 million of non-cancelable purchase commitments are attributable to third-party vendors that provides service as related to the ATI-RRPV Contract, that is reimbursable at approximately $7.7 million under a cost-plus-fixed-fees arrangement.

Previous wording

Intangible assets comprise developed technology and intellectual property. Intangible assets are carried at cost less accumulated amortization. Amortization is computed using the straight-line method over useful life of 11.75 years for developed technology and 20 years for intellectual property. The fair value as of March 31, 2026 is being amortized on a straight-line basis over the remaining period of 3.6 years and 1.8 years for developed technology and intellectual property, respectively.

Current wording

Intangible assets comprise developed technology and intellectual property. Intangible assets are carried at cost less accumulated amortization. Amortization is computed using the straight-line method over useful life of 11.75 years for developed technology and 20 years for intellectual property. The fair value as of June 30, 2026 is being amortized on a straight-line basis over the remaining period of 3.4 years and 1.5 years for developed technology and intellectual property, respectively.

Previous wording

Expected term – This represents the period that our stock-based awards granted are expected to be outstanding and is determined using the simplified method (the arithmetic average of its original contractual term and its average vesting term). We have very limited historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for our stock-based awards. Based on the weighted average applied to options awarded in the three months ended March 31, 2026, a notional 10% decrease in expected term would have reduced the fair value and the related compensation expense by approximately 2.4%.

Current wording

Expected term – This represents the period that our stock-based awards granted are expected to be outstanding and is determined using the simplified method (the arithmetic average of its original contractual term and its average vesting term). We have very limited historical information to develop reasonable expectations about future exercise patterns and post-vesting employment termination behavior for our stock-based awards. Based on the weighted average applied to options awarded in the six months ended June 30, 2026, a notional 10% decrease in expected term would have reduced the fair value and the related compensation expense by approximately 2.3%.

Previous wording

Expected volatility – This is a measure of the amount by which our common stock price has fluctuated or is expected to fluctuate. Since the beginning of 2020, we have measured volatility based on the historical volatility of our own stock over the retrospective period corresponding to the expected term of the options on the measurement date. Based on the weighted average applied to options awarded in the three months ended March 31, 2026, a notional 10% decrease in expected volatility (from 118.4% to 106.5%) would have reduced the fair value and the related compensation expense by approximately 4.6%.

Current wording

Expected volatility – This is a measure of the amount by which our common stock price has fluctuated or is expected to fluctuate. Since the beginning of 2020, we have measured volatility based on the historical volatility of our own stock over the retrospective period corresponding to the expected term of the options on the measurement date. Based on the weighted average applied to options awarded in the six months ended June 30, 2026, a notional 10% decrease in expected volatility (from 124.1% to 111.7%) would have reduced the fair value and the related compensation expense by approximately 4.3%.