Vaxcyte, Inc.

Previous wording

•PCV candidates that we believe are among the broadest-spectrum PCV candidates currently in development, targeting the approximately $8 billion global pneumococcal vaccine market. Pneumococcal disease ("PD") is an infection caused by Streptococcus pneumoniae bacteria. It can result in invasive pneumococcal disease (“IPD”), including meningitis and bacteremia, and non-invasive PD, including pneumonia, otitis media and sinusitis. Our broad-spectrum, carrier-sparing PCV candidates, VAX-31, VAX-24 and VAX-XL, are designed to improve upon standard-of-care PCVs for both adults and children by covering the serotypes that are responsible for increasing portions of IPD in circulation and are associated with high case-fatality rates, antibiotic resistance and meningitis, while maintaining coverage of previously circulating strains that are currently contained through continued vaccination.

Current wording

•Pneumococcal conjugate vaccine (“PCV”) candidates that we believe are among the broadest-spectrum PCV candidates currently in development, targeting the approximately $8.5 billion global pneumococcal vaccine market. Pneumococcal disease (“PD”) is an infection caused by Streptococcus pneumoniae bacteria. It can result in invasive pneumococcal disease (“IPD”), including meningitis and bacteremia, and non-invasive PD, including pneumonia, otitis media and sinusitis. Our broad-spectrum, carrier-sparing PCV candidates, VAX-31, VAX-24 and VAX-XL, are designed to improve upon standard-of-care PCVs for both adults and children by covering the serotypes that are responsible for increasing portions of IPD in circulation and are associated with high case-fatality rates, antibiotic resistance and meningitis, while maintaining coverage of previously circulating strains that are currently contained through continued vaccination.

Previous wording

•In December 2025, following an FDA End-of-Phase 2 meeting, we announced that the first participants were dosed in a Phase 3 pivotal, non-inferiority trial ("OPUS-1") evaluating the safety, tolerability and immune responses of VAX-31 in healthy, pneumococcal-naïve (defined as having no known prior history of IPD or pneumococcal pneumonia, or receipt of any licensed or investigational pneumococcal vaccine) adults aged 50 and older through direct, head-to-head comparisons with both PVC20 and PCV21, the current standard-of-care PCVs. In March 2026, we announced that we completed enrollment of this trial. We expect to announce topline safety, tolerability and immunogenicity data from this study in the fourth quarter of 2026.

Current wording

•In October 2026, we announced positive topline results from the pivotal adult Phase 3 trial of VAX-31 (“OPUS-1”). OPUS-1 is a randomized, double-blind, active-controlled Phase 3 trial which evaluated the safety, tolerability and immunogenicity of VAX-31 in healthy, pneumococcal-naïve U.S. adults (defined as having no known prior history of IPD or pneumococcal pneumonia, or receipt of any licensed or investigational pneumococcal vaccine) aged 50 years and older (n=3,572) through direct, head-to-head comparisons with both Prevnar 20® (“PCV20”) and/or Capvaxive®(“PCV21”), the current standard-of-care PCVs, with a separate cohort of adults aged 18-49 years

Previous wording

•In January 2026, we announced the initiation of an additional Phase 3 trial evaluating VAX-31 when administered concomitantly with a licensed, high-dose seasonal influenza vaccine in pneumococcal-naïve adults aged 50 years and older (“OPUS-2”). In February 2026, we announced the initiation of a separate Phase 3 study evaluating VAX-31 in adults previously vaccinated with a lower-valency pneumococcal vaccine (“OPUS-3”). In March 2026, we announced we completed enrollment of the OPUS-2 trial and in May 2026, we announced we completed enrollment of the OPUS-3 trial. We expect to report safety, tolerability and immunogenicity data from the OPUS-2 and OPUS-3 studies in the first half of 2027. We are also planning for a manufacturing consistency study (e.g., a lot-to-lot study) as the final Phase 3 study to enable the submission of the Biologics License Application (BLA).

Current wording

•In January 2026, we announced the initiation of a Phase 3 descriptive study evaluating the safety, tolerability and immunogenicity of VAX-31 when administered either concomitantly with or one month following administration of a licensed seasonal influenza vaccine in healthy, pneumococcal-naïve adults aged 50 years and older (“OPUS-2”). In February 2026, we announced the initiation of a separate Phase 3 descriptive study evaluating the safety, tolerability and immunogenicity of VAX-31 in healthy U.S. adults aged 50 years or older who have previously received pneumococcal vaccination (“OPUS-3”). In March 2026, we announced we completed enrollment of the OPUS-2 trial and in May 2026, we announced we completed enrollment of the OPUS-3 trial. We expect to report safety, tolerability and immunogenicity data from the OPUS-2 and OPUS-3 studies in the first half of 2027. We are also planning for a manufacturing consistency study (e.g., a lot-to-lot study) as the final Phase 3 study to enable the submission of the Biologics License Application (“BLA”).

Previous wording

•In November 2024, we announced that the U.S. Food and Drug Administration ("FDA") granted breakthrough therapy designation ("BTD") for VAX-31 for the prevention of IPD in adults and, in August 2025, we announced that the FDA expanded the BTD for VAX-31 to include the prevention of pneumonia caused by Streptococcus pneumoniae.

Current wording

•The U.S. Food and Drug Administration (“FDA”) has granted breakthrough therapy designation for VAX-31 in adults for the prevention of IPD and pneumonia caused by Streptococcus pneumoniae.

Previous wording

•In September 2024, we announced positive topline results from a Phase 1/2 study of VAX-31 in adults. The VAX-31 Phase 1/2 clinical study was a randomized, observer-blind, active-controlled, dose-finding clinical study designed to evaluate the safety, tolerability and immunogenicity of a single injection of VAX-31 at three dose levels (Low, Middle and High) and compared to Prevnar 20®("PCV20") in 1,015 healthy adults aged 50 and older. In the Low, Middle and High Doses, all serotypes were dosed at 1.1mcg, 2.2mcg and 3.3mcg, respectively, except serotypes 1, 5 and 22F, which were dosed at 1.65mcg, 3.3mcg, and 4.4mcg, respectively. The Phase 1 portion of the study included 64 healthy adults 50 to 64 years of age and the Phase 2 portion included 951 healthy adults 50 years of age and older. The immunogenicity objectives of the study included an assessment of the induction of antibody responses at Month 1, based on opsonophagocytic activity (“OPA”) and immunoglobulin G ("IgG"), at each of the three VAX-31 doses and compared to PCV20 for the 20 serotypes in common, as well as for the additional 11 serotypes contained in VAX-31, but not in PCV20.

Current wording

•In September 2024, prior to the initiation of our VAX-31 adult Phase 3 program, we announced positive topline results from a Phase 1/2 study of VAX-31 in adults. The VAX-31 Phase 1/2 clinical study was a randomized, observer-blind, active-controlled, dose-finding clinical study designed to evaluate the safety, tolerability and immunogenicity of a single injection of VAX-31 at three dose levels (Low, Middle and High) and compared to PCV20 in 1,015 healthy adults aged 50 and older.

Previous wording

In the Phase 1/2 study, VAX-31 was observed to be well tolerated and demonstrated a safety profile at all doses studied through the full six-month evaluation period similar to PCV20. VAX-31 showed robust OPA immune responses for all 31 serotypes at all doses studied. At the Middle and High Doses, VAX-31 met or exceeded the regulatory immunogenicity criteria for all 31 serotypes and, at the Low Dose, for 29 of 31 serotypes. At the VAX-31 High Dose, average OPA immune responses were greater for 18 of 20 serotypes compared to PCV20 (geometric mean ratio (“GMR”) greater than 1.0), with seven of these serotypes achieving statistically higher immune responses compared to PCV20. At the Middle Dose, 13 of 20 serotypes had a GMR greater than 1.0 and five serotypes achieved statistically higher immune responses compared to PCV20. At the Low Dose, 18 of 20 serotypes met the OPA response non-inferiority criteria, 8 of 20 serotypes had a GMR greater than 1.0 and three serotypes achieved statistically higher immune responses. For all 11 incremental serotypes unique to VAX-31, and not in PCV20, all three doses met the superiority criteria.

Current wording

•VAX-31 was observed to be well tolerated and demonstrated a safety profile at all doses studied through the full six-month evaluation period similar to PCV20. VAX-31 showed robust OPA immune responses for all 31 serotypes at all doses studied. At the VAX-31 High Dose, average OPA immune responses were greater for 18 of 20 serotypes compared to PCV20 (GMR greater than 1.0), with seven of these serotypes achieving statistically higher immune responses compared to PCV20. For all 11 incremental serotypes unique to VAX-31, and not in PCV20, all three doses met the superiority criteria.

Previous wording

Based on these positive results, we selected the High Dose of VAX-31 to advance to an adult Phase 3 program.

Current wording

•Based on these positive results, we selected the High Dose of VAX-31 to advance to our adult Phase 3 program.

Previous wording

▪In December 2024, we announced that the first participants were dosed in the first stage of a Phase 2, randomized, dose-finding study of VAX-31 in infants. Stage 1 of the study evaluated the safety and tolerability of VAX-31 at three dose levels (Low, Middle and High) and compared to PCV20 in 48 infants in a dose-escalation approach. In the Low, Middle and High Doses, all serotypes were dosed at 1.1mcg, 2.2mcg and

Current wording

•In December 2024, we announced that the first participants were dosed in the first stage of a Phase 2, randomized, dose-finding study of VAX-31 in infants. Stage 1 of the study evaluated the safety and tolerability of VAX-31 at three dose levels (Low, Middle and High) and compared to PCV20 in 48 infants in a dose-escalation approach. In the Low, Middle and High Doses, all serotypes were dosed at 1.1mcg, 2.2mcg and 3.3mcg, respectively, except serotypes 1, 5 and 22F, which were dosed at 1.65mcg, 3.3mcg, and 4.4mcg, respectively. Participants who received VAX-31 in Stage 1 continued the standard dosing regimen as part of Stage 2.

Previous wording

▪Pending the VAX-31 Phase 2 infant study readout, we plan to initiate a Phase 3 program in infants with an Optimized Dose formulation of VAX-24 or VAX-31.

Current wording

•Pending the VAX-31 Phase 2 infant study readout, we plan to initiate a Phase 3 program in infants with VAX-24 or VAX-31.

Previous wording

•Post-dose 3, all VAX-24 doses met target precedent Phase 2 non-inferiority criteria on relative seroconversion rates (lower limit of the 95% confidence interval for the difference between the proportion of participants achieving the pre-defined seroconversion rate (IgG concentration ≥0.35 mcg/mL) is > -15% for each serotype) for the highest circulating serotypes, as defined by the percentage of IPD caused in individuals <5 yrs of age in the U.S. in 2023 based on the U.S. Center for Disease Control ("CDC") active bacterial core ("ABC") surveillance data, contained in VAX-24. The Low and Mid doses met the seroconversion rate criteria for 20 of 24 serotypes overall and the Mixed Dose met such criteria for 19 of 24 serotypes. The Mid and Mixed Doses met the target Phase 2 IgG GMR point estimate of >0.6 for 21 of 24 serotypes.

Current wording

•Post-dose 3, all VAX-24 doses met target precedent Phase 2 non-inferiority criteria on relative seroconversion rates (lower limit of the 95% confidence interval for the difference between the proportion of participants achieving the pre-defined seroconversion rate (IgG concentration ≥0.35 mcg/mL) is > -15% for each serotype) for the highest circulating serotypes, as defined by the percentage of IPD caused in individuals <5 years of age in the U.S. in 2023 based on the U.S. Center for Disease Control (“CDC”) active bacterial core (“ABC”) surveillance data, contained in VAX-24. The Low and Mid doses met the seroconversion rate criteria for 20 of 24 serotypes overall and the Mixed Dose met such criteria for 19 of 24 serotypes. The Mid and Mixed Doses met the target Phase 2 IgG GMR point estimate of >0.6 for 21 of 24 serotypes.

Previous wording

•VAX-A1, a novel conjugate vaccine candidate designed to prevent disease caused by Group A Streptococcus (Streptococcus pyogenes) (“Group A Strep”). Group A Strep is pervasive globally and causes an estimated 800 million cases of illness annually, including pharyngitis, or strep throat, and certain severe invasive infections and sequelae. There is currently no vaccine against Group A Strep, which is one of the leading infectious disease-related causes of death and disability worldwide and a significant contributor to the prescription of antibiotics in children. We believe we have demonstrated preclinical proof of concept for VAX-A1, the data for which were published in December 2020. In June 2026, we initiated a Phase 1 adult study for VAX-A1, with the primary objective of assessing safety and tolerability, along with a secondary objective of evaluating initial immunogenicity data, to support potential further advancement. We expect to report topline data from this study in the second half of 2027.

Current wording

•VAX-A1, a novel conjugate vaccine candidate designed to prevent disease caused by Group A Streptococcus (Streptococcus pyogenes) (“Group A Strep”). Group A Strep is pervasive globally and causes an estimated 800 million cases of illness annually, including pharyngitis, or strep throat, and certain severe invasive infections and sequelae. There is currently no vaccine against Group A Strep, which is one of the leading infectious disease-related causes of death and disability worldwide and a significant contributor to the prescription of antibiotics in children. We believe we have demonstrated preclinical proof of concept for VAX-A1, the data for which were published in December 2020. In June 2026, we initiated a Phase 1 adult study for VAX-A1, with the primary objective of assessing safety and tolerability, along with a secondary objective of evaluating initial immunogenicity data, to support potential further advancement. The study is advancing to Stage 2 following the completion of an independent Data Safety Monitoring Board (“DSMB”) review of Stage 1 safety and tolerability data. We are completing plans to initiate Stage 2 including an updated study design that incorporates the DSMB’s recommendations for sequential enrollment, beginning with the Low and Mid Dose cohorts. Enrollment of the High Dose cohort will be part of a new Stage 3 and will follow completion of the prespecified safety assessments and further DSMB review and approval. The study design has also been updated to add a third vaccination at the Low and Mid Dose levels, while the High Dose regimen remains two vaccinations. We expect to report topline data from this study in the second half of 2027.

Previous wording

Since our inception in November 2013, we have devoted substantially all of our resources to performing research and development, undertaking preclinical studies, advancing our vaccine candidates through clinical trials, enabling manufacturing activities in support of our product development efforts, acquiring and developing our technology and vaccine candidates, organizing and staffing our company, performing business planning, establishing our intellectual property portfolio and raising capital to support and expand such activities. We do not have any products approved for sale and have not generated any revenue from product sales. To date, we have financed our operations primarily with proceeds from the sales of our common stock, pre-funded warrants to purchase our common stock and, prior to our initial public offering (“IPO”) in June 2020, redeemable convertible preferred stock. We will continue to require additional capital to develop and commercialize our vaccine candidates and fund operations for the foreseeable future. Accordingly, until such time as we can generate significant revenue from sales of our vaccine candidates, if ever, we expect to finance our cash needs through public or private equity or debt financings, third-party (including government) funding and marketing and distribution arrangements, as well as other collaborations, strategic alliances and licensing arrangements, or any combination of these approaches.

Current wording

Since our inception in November 2013, we have devoted substantially all of our resources to performing research and development, undertaking preclinical studies, advancing our vaccine candidates through clinical trials, enabling manufacturing activities in support of our product development efforts, acquiring and developing our technology and vaccine candidates, organizing and staffing our company, performing business planning, establishing our intellectual property portfolio and raising capital to support and expand such activities. We do not have any products approved for sale and have not generated any revenue from product sales. To date, we have financed our operations primarily with proceeds from the sales of our common stock, pre-funded warrants to purchase our common stock, issuance of convertible senior notes and, prior to our initial public offering (“IPO”) in June 2020, redeemable convertible preferred stock. We will continue to require additional capital to develop and commercialize our vaccine candidates and fund operations for the foreseeable future. Accordingly, until such time as we can generate significant revenue from sales of our vaccine candidates, if ever, we expect to finance our cash needs through public or private equity or debt financings, third-party (including government) funding and marketing and distribution arrangements, as well as other collaborations, strategic alliances and licensing arrangements, or any combination of these approaches.

Previous wording

We have incurred net losses in each year since inception and expect to continue to incur net losses in the foreseeable future. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending in large part on the timing of our clinical trials and manufacturing activities, and our expenditures on other research and development activities. Our net loss was $284.3 million and $604.9 million for the three and six months, respectively, ended June 30, 2026. As of June 30, 2026, we had an accumulated deficit of $2.8 billion and cash, cash equivalents and investments of $2.5 billion. We believe our cash, cash equivalents and investments will be sufficient to fund our operating expenses and capital expenditure requirements through at least 12 months from the filing date of this Quarterly Report on Form 10-Q.

Current wording

We have incurred net losses in each year since inception and expect to continue to incur net losses in the foreseeable future. Our net losses may fluctuate significantly from quarter-to-quarter and year-to-year, depending in large part on the timing of our clinical trials and manufacturing activities, and our expenditures on other research and development activities. Our net loss was $297.1 million and $902.0 million for the three and nine months, respectively, ended September 30, 2026. As of September 30, 2026, we had an accumulated deficit of $3.1 billion and cash, cash equivalents and investments of $2.3 billion. We believe our cash, cash equivalents and investments will be sufficient to fund our operating expenses and capital expenditure requirements through at least 12 months from the filing date of this Quarterly Report on Form 10-Q.

Previous wording

We do not expect to generate any revenue from commercial product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our vaccine candidates, which we expect will take a number of years. We expect our expenses will increase in connection with our ongoing activities, as we:

Current wording

We do not expect to generate any revenue from commercial product sales unless and until we successfully complete development and obtain regulatory approval for one or more of our vaccine candidates. We expect our expenses will continue to remain high in connection with our ongoing activities, as we:

Previous wording

In April 2022, we entered into a non-exclusive development and manufacturing services agreement with Lonza effective as of March 22, 2022, which was subsequently amended on May 12, 2022, November 21, 2022 and October 31, 2023 (as amended, the “2022 Lonza DMSA”). Pursuant to the 2022 Lonza DMSA, Lonza is obligated to perform services, including manufacturing process development and clinical manufacture and supply of our proprietary PCV candidates. Subject to the terms and conditions set forth in the 2022 Lonza DMSA, Lonza has granted to us a non-exclusive, worldwide, fully paid-up, irrevocable, transferable license, including the right to grant sublicenses, under the New General Application Intellectual Property, to research, develop, make, have made, use, sell and import the Product. Unless earlier terminated, the 2022 Lonza DMSA shall remain in place for a period of five years. Either party may terminate the 2022 Lonza DMSA for any reason on prior written notice to the other party, provided that Lonza may not exercise such right until a specified future date. In addition, either party may terminate the 2022 Lonza DMSA (i) within a given time period upon any material breach that is left uncured by the other party, or (ii) immediately if the other party becomes insolvent. We may also terminate the 2022 Lonza DMSA upon an extended force majeure event. Upon expiration and/or termination of the 2022 Lonza DMSA and/or any purchase order, we will pay Lonza for all service rendered, all costs incurred, all unreimbursed capital equipment and any cancellation fees (each term as defined in the 2022 Lonza DMSA).

Current wording

In April 2022, we entered into a non-exclusive development and manufacturing services agreement with Lonza effective as of March 22, 2022, which was subsequently amended on May 12, 2022, November 21, 2022 and October 31, 2023 (as amended, the “2022 Lonza DMSA”). Pursuant to the 2022 Lonza DMSA, Lonza is obligated to perform services, including manufacturing process development and clinical manufacture and supply of our proprietary PCV candidates. Subject to the terms and conditions set forth in the 2022 Lonza DMSA, Lonza has granted to us a non-exclusive, worldwide, fully paid-up, irrevocable, transferable license, including the right to grant sublicenses, under the New General Application Intellectual Property, to research, develop, make, have made, use, sell and import the Product. Unless earlier terminated, the 2022 Lonza DMSA shall remain in place for a period of five years. Either party may terminate the 2022 Lonza DMSA for any reason on prior written notice to the other party, provided that Lonza may not exercise such right until a specified future date. In addition, either party may terminate the 2022 Lonza DMSA (i) within a given time period upon any material breach that is left uncured by the other party, or (ii) immediately if the other party becomes insolvent. We may also terminate the 2022 Lonza DMSA upon an extended force majeure event. Upon expiration and/or termination of the 2022 Lonza DMSA and/or any purchase order, we will pay Lonza for all services rendered, all costs incurred, all unreimbursed capital equipment and any cancellation fees (each term as defined in the 2022 Lonza DMSA).

Previous wording

Pursuant to the Lonza Commercial Manufacturing and Supply Agreement, Lonza constructed and built out a dedicated suite (the “Suite”) at Lonza’s facilities in Visp, Switzerland to manufacture certain key components (including drug substance) for our proprietary PCV franchise and any other products or intermediates we may choose (collectively, the “Products”). Following completion of construction and certification of the Suite for commercial operation, the Suite was handed over to the Lonza operations team on August 1, 2026, and Lonza will now maintain and operate the Suite (utilizing Lonza’s employees) to manufacture the Products as a service provided to us, including conducting related quality control and quality assurance operations. Lonza is a preferred, non-exclusive, supplier of the Products to us, and we retain the right to procure the Products from one or more alternate and/or backup manufacturers of the Products (including at our own facilities).

Current wording

Pursuant to the Lonza Commercial Manufacturing and Supply Agreement, Lonza constructed and built out a dedicated suite (the “Suite”) at Lonza’s facilities in Visp, Switzerland to manufacture certain key components (including drug substance) for our proprietary PCV franchise and any other products or intermediates we may choose (collectively, the “Products”). Lonza is a preferred, non-exclusive, supplier of the Products to us, and we retain the right to procure the Products from one or more alternate and/or backup manufacturers of the Products (including at our own facilities).

Previous wording

Under the Lonza Commercial Manufacturing and Supply Agreement, prior to completion of construction and certification of the Suite for commercial operation, we contributed to the capital expenditure costs to construct the Suite (and own certain equipment in the Suite that was purchased or otherwise acquired by us), and paid Lonza a fixed-rate monthly service fee for Lonza’s pre-commercial services prior to commencement of commercial operations. We will now pay Lonza (i) Suite fees based on allocations of certain of Lonza’s costs to maintain the facility in which the Suite is located and to provide shared services to us and Lonza’s other customers in such facility, (ii) service fees based upon Lonza’s actual full-time equivalent employee (“FTE”) costs to operate the Suite to manufacture the Products, and (iii) equipment expenditures and certain other pass-through costs, including for raw materials. In addition, we may be obligated to pay or reimburse Lonza for certain other fees and expenses under the Lonza Commercial Manufacturing and Supply Agreement. Lonza will be eligible for certain financial bonuses, and subject to certain financial penalties, as incentives for the timely completion of certain scale-up activities, receipt of certain regulatory approvals for the Suite and manufacture of the Products in accordance with our commercial requirements.

Current wording

Under the Lonza Commercial Manufacturing and Supply Agreement, prior to completion of construction and certification of the Suite for commercial operation, we contributed to the capital expenditure costs to construct the Suite (and own certain equipment in the Suite that was purchased or otherwise acquired by us), and paid Lonza a fixed-rate monthly service fee for Lonza’s pre-commercial services prior to commencement of commercial operations. Following completion of construction and certification of the Suite for commercial operation, the Suite was transferred to the Lonza operations team in August 2026, at which time the lease was deemed to have commenced. Lonza now maintains and operates the Suite, utilizing their employees, to manufacture the Products on our behalf, including conducting related quality control and quality assurance activities. We are now obligated to pay Lonza (i) Suite fees based on allocations of certain of Lonza’s costs to maintain the facility in which the Suite is located and to provide shared services to us and Lonza’s other customers in such facility, (ii) service fees based upon Lonza’s actual full-time equivalent employee (“FTE”) costs to operate the Suite to manufacture the Products, and (iii) equipment expenditures and certain other pass-through costs, including for raw materials. In addition, we may be obligated to pay or reimburse Lonza for certain other fees and expenses under the Lonza Commercial Manufacturing and Supply Agreement. Lonza is eligible for certain financial bonuses, and subject to certain financial penalties, as incentives for the timely completion of certain scale-up activities, receipt of certain regulatory approvals for the Suite and manufacture of the Products in accordance with our commercial requirements.

Previous wording

Unless earlier terminated, the Lonza Commercial Manufacturing and Supply Agreement will remain in effect until December 31, 2038, subject to automatic renewal for up to three additional renewal periods of five years each, unless we elect not to renew (with 24 months advanced notice to Lonza). We are permitted to terminate the Lonza Commercial Manufacturing and Supply Agreement prior to expiration, subject to applicable termination fees. Within 30 days of the Effective Date, we paid Lonza a repurposing fee (the “Repurposing Fee”) of CHF 27.0 million that will be credited back to us over a 10-year period starting upon commencement of commercial production.

Current wording

Unless earlier terminated, the Lonza Commercial Manufacturing and Supply Agreement will remain in effect until December 31, 2038, subject to automatic renewal for up to three additional renewal periods of five years each, unless we elect not to renew (with 24 months advanced notice to Lonza). We are permitted to terminate the Lonza Commercial Manufacturing and Supply Agreement for convenience or for Lonza’s uncured material breach, in each case subject to certain notice obligations. Lonza is permitted to terminate the Lonza Commercial Manufacturing and Supply Agreement in the event that we commit certain specified material breaches, including uncured failure to pay material and undisputed amounts of money due to Lonza, subject to certain notice obligations. Either party may terminate the Commercial Manufacturing and Supply Agreement in certain circumstances in the event of the other party’s bankruptcy. In the event that we terminate the agreement for convenience, or Lonza terminates the agreement in the event that we commit certain specified material breaches, then certain termination consequences may be triggered, including that (i) we would forfeit any outstanding entitlement to credit from Lonza of the Repurposing Fee (as defined below), and (ii) we would be obligated to pay Lonza a termination penalty equal to the greater of (a) CHF 70.0 million or (b) a prespecified number of months’ FTE fees for the actual FTEs assigned to us as of the date of termination. Within 30 days of the Effective Date, we paid Lonza a repurposing fee (the “Repurposing Fee”) of CHF 27.0 million that will be credited back to us over a 10-year period starting upon commencement of commercial production. In the event of a termination under certain circumstances, Lonza shall be obligated to provide certain wind-down and transition services to us for up to 12 months and 24 months, respectively.

Previous wording

In May 2018, we entered into a supply agreement with Sutro Biopharma, which was subsequently amended on February 22, 2021 and November 21, 2023 (as amended, the “Sutro Biopharma Supply Agreement”) pursuant to which we purchase from Sutro Biopharma extract and custom reagents for use in manufacturing non-clinical and certain clinical supply of vaccine compositions utilizing the technology licensed under the Sutro Biopharma License at prices not to exceed a specified percentage above Sutro Biopharma’s fully burdened manufacturing cost. If any extracts or custom reagents do not meet the specifications and warranties provided, then we will not have an obligation to pay for the non-conforming product, and Sutro Biopharma will be obligated to replace the non-conforming product within the shortest possible time with conforming product at our cost. The term of the Sutro Biopharma Supply Agreement is from execution until the later of (i) July 31, 2022, or (ii) the date that we and Sutro Biopharma enter into the Phase 3/Commercial Supply Agreement and

Current wording

In May 2018, we entered into a supply agreement with Sutro Biopharma, which was subsequently amended on February 22, 2021 and November 21, 2023 (as amended, the “Sutro Biopharma Supply Agreement”) pursuant to which we purchase from Sutro Biopharma extract and custom reagents for use in manufacturing non-clinical and certain clinical supply of vaccine compositions utilizing the technology licensed under the Sutro Biopharma License at prices not to exceed a specified percentage above Sutro Biopharma’s fully burdened manufacturing cost. If any extracts or custom reagents do not meet the specifications and warranties provided, then we will not have an obligation to pay for the non-conforming product, and Sutro Biopharma will be obligated to replace the non-conforming product within the shortest possible time with conforming product at our cost. The term of the Sutro Biopharma Supply Agreement is from execution until the later of (i) July 31, 2022, or (ii) the date that we and Sutro Biopharma enter into the Phase 3/Commercial Supply Agreement and Sutro Biopharma is supplying to us each Product under the Phase 3/Commercial Supply Agreement (each term as defined in the Sutro Biopharma Supply Agreement). The Sutro Biopharma Supply Agreement may be terminated by either party for the other party’s material breach uncured within 60 days’ notice, by us at will with 60 days’ notice, or by mutual agreement of the parties. In December 2019, we exercised our right to require Sutro Biopharma to establish a second supplier for extract and custom reagents to support our anticipated clinical and commercial needs.

Previous wording

As consideration for the Option and other rights and authorizations granted to us under the Option Agreement, we paid Sutro Biopharma upfront consideration of $22.5 million, consisting of (i) $10.0 million in cash and $7.5 million worth of shares of our common stock (the number of shares calculated based on the arithmetic average of the daily volume weighted average price of our common stock as traded on Nasdaq in the three consecutive trading days immediately prior to the issuance thereof) in December 2022, and (ii) $5.0 million in October 2023 within five business days after we and Sutro Biopharma mutually agree in writing upon the Form Definitive Agreement on September 28, 2023. The 167,780 shares of common stock issued was recorded at fair value of $8.0 million on the date of settlement, December 22, 2022.

Current wording

As consideration for the Option and other rights and authorizations granted to us under the Option Agreement, we paid Sutro Biopharma upfront consideration of $22.5 million, consisting of (i) $10.0 million in cash and $7.5 million worth of shares of our common stock (the number of shares calculated based on the arithmetic average of the daily volume weighted average price of our common stock as traded on Nasdaq in the three consecutive trading days immediately prior to the issuance thereof) in December 2022, and (ii) $5.0 million in October 2023 within five business days after we and Sutro Biopharma mutually agreed in writing upon the Form Definitive Agreement on September 28, 2023. The 167,780 shares of common stock issued were recorded at fair value of $8.0 million on the date of settlement, December 22, 2022.

Previous wording

We expect our research and development expenses to increase in absolute dollars for the foreseeable future as we advance our vaccine candidates into and through preclinical studies and clinical trials, manufacture drug product for our clinical trials and to support the potential initial commercial launch of VAX-31 in the adult population, scale up our manufacturing activities, establish additional manufacturing capacity to meet potential incremental supply requirements following the potential commercial launches of VAX-31 in the adult population and VAX-31 or VAX-24 in the pediatric population, pursue regulatory approval of our vaccine candidates and expand our pipeline of vaccine candidates. The process of conducting the necessary preclinical and clinical research and completing the manufacturing requirements to obtain regulatory approval is costly and time-consuming. The actual probability of success for our vaccine candidates may be affected by a variety of factors, including the safety and efficacy or immunogenicity of our vaccine candidates, clinical data, investment in our clinical programs, competition, manufacturing capabilities and commercial viability. We may never succeed in achieving regulatory approval for any of our vaccine candidates. As a result of the uncertainties discussed above, we are unable to determine the duration and completion costs of our research and development projects or if, when and to what extent we will generate revenue from the commercialization and sale of our vaccine candidates.

Current wording

We expect our research and development expenses to remain high in absolute dollars for the foreseeable future as we advance our vaccine candidates into and through preclinical studies and clinical trials, manufacture drug product for our clinical trials and to support the potential initial commercial launch of VAX-31 in the adult population, scale up our manufacturing activities, establish additional manufacturing capacity to meet potential incremental supply requirements following the potential commercial launches of VAX-31 in the adult population and VAX-31 or VAX-24 in the pediatric population, pursue regulatory approval of our vaccine candidates and expand our pipeline of vaccine candidates. The process of conducting the necessary preclinical and clinical research and completing the manufacturing requirements to obtain regulatory approval is costly and time-consuming. The actual probability of success for our vaccine candidates may be affected by a variety of factors, including the safety and efficacy or immunogenicity of our vaccine candidates, clinical data, investment in our clinical programs, competition, manufacturing capabilities and commercial viability. We may never succeed in achieving regulatory approval for any of our vaccine candidates. As a result of the uncertainties discussed above, we are unable to determine the duration and completion costs of our research and development projects or if, when and to what extent we will generate revenue from the commercialization and sale of our vaccine candidates.

Previous wording

General and administrative expenses consist primarily of costs and expenses related to personnel (including salaries, employee benefits and stock-based compensation) in our executive, legal, finance and accounting, human resources and other administrative functions; legal services relating to intellectual property and corporate matters; accounting, auditing, consulting and tax services; insurance; and facility and other allocated shared costs not otherwise included in research and development expenses. We expect our general and administrative expenses to continue to increase in absolute dollars for the foreseeable future as we increase our headcount and expand our services to support our continued research and development activities and grow our business.

Current wording

General and administrative expenses consist primarily of costs and expenses related to personnel (including salaries, employee benefits and stock-based compensation) in our executive, commercial, legal, finance and accounting, human resources and other administrative functions; legal services relating to intellectual property and corporate matters; accounting, auditing, consulting and tax services; insurance; and facility and other allocated shared costs not otherwise included in research and development expenses. We expect our general and administrative expenses to continue to increase in absolute dollars for the foreseeable future as we increase our headcount and expand our services to support our continued research and development activities and grow our business.

Previous wording

We are currently working on a discovery program with the University of North Carolina at Chapel Hill and the University of Chicago to develop a vaccine candidate for the prevention of Chlamydia, which is funded in part by a grant from the NIAID that provides potential funding up to five years totaling approximately $9.5 million. As of June 30, 2026, we have received and expect to continue to receive funding under this grant.

Current wording

We are currently working on a discovery program with the University of North Carolina at Chapel Hill and the University of Chicago to develop a vaccine candidate for the prevention of Chlamydia, which is funded in part by a grant from the National Institute of Allergy and Infectious Diseases that provides potential funding up to five years totaling approximately $9.5 million. As of September 30, 2026, we have received and expect to continue to receive funding under this grant.

Previous wording

Income from grants is recognized in the period during which the related specified expenses are incurred, provided that the conditions under which the grants were provided have been met. The amount of grant income was not material during the three and six months ended June 30, 2026 and June 30, 2025. Grant income is included as a component of Other income, net in the condensed consolidated statements of operations.

Current wording

Income from grants is recognized in the period during which the related specified expenses are incurred, provided that the conditions under which the grants were provided have been met. The amount of grant income was not material during the three and nine months ended September 30, 2026 and September 30, 2025. Grant income is included as a component of Other income, net in the condensed consolidated statements of operations.

Previous wording

Comparison of the Three and Six Months Ended June 30, 2026 and 2025

Current wording

Comparison of the Three and Nine Months Ended September 30, 2026 and 2025

Previous wording

Research and development expenses increased by $73.7 million, or 37.9%, during the three months ended June 30, 2026, compared to the corresponding period in 2025. The increase was largely driven by external costs, which grew by $64.1 million primarily due to increased activities related to clinical trials and product manufacturing in connection with our PCV programs. Clinical trials-related expenses increased by $25.4 million primarily due to the activities associated with the VAX-31 OPUS-1, OPUS-2, and OPUS-3 Phase 3 studies. Product manufacturing costs increased by $23.2 million primarily driven by increased manufacturing activities to support the potential future commercial launches. Research expenses increased by $13.3 million, and other external costs increased by $1.9 million compared to the corresponding period in 2025. The increase was further driven by internal personnel-related costs, which grew by $9.6 million, primarily due to headcount growth.

Current wording

Research and development expenses increased by $60.4 million, or 28.8%, during the three months ended September 30, 2026, compared to the corresponding period in 2025. The increase was largely driven by external costs, which grew by $47.8 million primarily due to increased activities related to clinical trials and product manufacturing in connection with our PCV programs. Product manufacturing costs increased by $20.2 million primarily driven by increased manufacturing activities to support potential future commercial launches. Clinical trials-related expenses increased by $18.7 million primarily due to the activities associated with the VAX-31 OPUS-1, OPUS-2 and OPUS-3 Phase 3 studies. Research expenses increased by $4.8 million driven by research and assay services, and other external costs increased by $2.4 million. The increase was further driven by internal personnel-related costs, which grew by $12.6 million, primarily due to headcount growth to support our research and development efforts.

Previous wording

Research and development expenses increased by $238.3 million, or 69.6% during the six months ended June 30, 2026 compared to the corresponding period in 2025. The increase was driven by external costs, which grew by $216.7 million largely due to increased activities related to product manufacturing and clinical trials in connection with our PCV programs. Product manufacturing costs increased by $127.0 million due to an increase in manufacturing activities, including to support the potential future commercial launches, Clinical trials-related expenses increased by $70.5 million, primarily due to the initiation of and enrollment in the VAX-31 OPUS-1, OPUS-2 and OPUS-3 Phase 3 studies, Research expenses increased by $16.1 million, and other external costs increased by $2.5 million compared to the corresponding period in 2025. The increase was further driven by internal personnel-related costs, which grew by $21.6 million largely due to headcount growth.

Current wording

Research and development expenses increased by $298.7 million, or 54.1%, during the nine months ended September 30, 2026 compared to the corresponding period in 2025. The increase was largely driven by external costs, which grew by $264.5 million primarily due to increased activities related to product manufacturing and clinical trials in connection with our PCV programs. Product manufacturing costs increased by $147.2 million due to an increase in manufacturing activities in preparation for potential future commercial launches. Clinical trials-related expenses increased by $89.2 million primarily due to the initiation of and enrollment in the VAX-31 OPUS-1, OPUS-2 and OPUS-3 Phase 3 studies. Research expenses increased by $21.0 million, primarily due to higher contracted research services utilized and increased expensed lab equipment costs, reflecting the expansion of research activities. Other external costs increased by $4.9 million, primarily driven by a $1.9 million increase in consulting and contractor services utilized and a $2.6 million increase in shipment costs associated with our expanded PCV programs. The increase was further driven by internal personnel-related costs, which grew by $34.2 million largely due to headcount growth to support our research and development efforts.

Previous wording

General and administrative expenses increased by $3.3 million, or 5.1%, during the six months ended June 30, 2026 compared to the corresponding period in 2025 which was driven primarily by an increase in internal personnel-related costs due to headcount growth

Current wording

General and administrative expenses increased by $5.5 million, or 17.0%, during the three months ended September 30, 2026 compared to the corresponding period in 2025, which was driven primarily by a $3.3 million increase in internal personnel-related costs due to headcount growth and a $2.2 million increase in professional and consulting services.

Previous wording

General and administrative expenses increased by $2.9 million, or 9.0% during the three months ended June 30, 2026 compared to the corresponding period in 2025, which was driven primarily by an increase in internal personnel-related costs due to headcount growth.

Current wording

General and administrative expenses increased by $8.8 million, or 9.1%, during the nine months ended September 30, 2026 compared to the corresponding period in 2025 due primarily to an increase in internal personnel-related costs due to headcount growth.

Previous wording

Other income, net decreased by $41.2 million, or 69.0%, during the three months ended June 30, 2026 compared to the corresponding period in 2025. The decrease was primarily attributable to a $35.9 million reduction in unrealized and realized foreign currency gains due to fluctuations in the foreign currency exchange rates and a $5.3 million decrease in interest income as a result of lower cash and investment balances and lower interest rates during the period.

Current wording

Other income, net decreased by $18.3 million, or 62.1%, during the three months ended September 30, 2026 compared to the corresponding period in 2025. The decrease was primarily attributable to a $12.0 million reduction in unrealized and realized foreign currency gains due to fluctuations in foreign currency exchange rates and a $6.1 million decrease in interest income, due to lower average investment balances and lower interest rates.

Previous wording

Other income, net decreased by $56.0 million, or 56.2%, during the six months ended June 30, 2026 compared to the corresponding period in 2025. The decrease was primarily attributable to a $44.4 million reduction in unrealized and realized foreign currency gains due to fluctuations in the foreign currency exchange rates and a $11.6 million decrease in interest income as a result of lower cash and investment balances and lower interest rates during the period.

Current wording

Other income, net decreased by $74.4 million, or 57.5%, during the nine months ended September 30, 2026 compared to the corresponding period in 2025. The decrease was primarily attributable to a $57.7 million reduction in unrealized and realized foreign currency gains due to fluctuations in foreign currency exchange rates and a $17.7 million decrease in interest income due to lower average investment balances and lower interest rates.

Previous wording

From inception through June 30, 2026, we have incurred losses and negative cash flows from operations and have funded our operations primarily through the issuance of common stock, pre-funded warrants to purchase our common stock and, prior to our IPO, redeemable convertible preferred stock, totaling approximately $5.3 billion in aggregate gross proceeds and $5.1 billion net of underwriting discounts, commissions and offering expenses. As of June 30, 2026, we had $0.2 billion in cash and cash equivalents, $2.3 billion in investments and an accumulated deficit of $2.8 billion.

Current wording

From inception through September 30, 2026, we have incurred losses and negative cash flows from operations and have funded our operations primarily through the issuance of common stock, pre-funded warrants to purchase our common stock and, prior to our IPO, redeemable convertible preferred stock, totaling approximately $5.3 billion in aggregate gross proceeds and $5.1 billion net of underwriting discounts, commissions and offering expenses. As of September 30, 2026, we had $0.1 billion in cash and cash equivalents, $2.1 billion in investments and an accumulated deficit of $3.1 billion.

Previous wording

During the three and six months ended June 30, 2025, 640,705 and 4,140,705 shares underlying the pre-funded warrants were exercised, respectively, to receive 640,685 and 4,140,644 shares of common stock, respectively, net of exercise costs. No shares underlying the pre-funded warrants were exercised during the three and six months ended June 30, 2026. As of both June 30, 2026 and December 31, 2025, a total of 5,463,793 shares underlying pre-funded warrants were outstanding.

Current wording

During the three and nine months ended September 30, 2026, 3,946,094 shares underlying the pre-funded warrants were exercised to receive 3,946,020 shares of common stock, net of exercise costs. During the three months ended September 30, 2025, no shares underlying the pre-funded warrants were exercised. During the nine months ended September 30, 2025, 4,140,705 shares underlying the pre-funded warrants were exercised, to receive 4,140,644 shares of common stock, net of exercise costs. As of September 30, 2026 and December 31, 2025, a total of 1,517,699 and 5,463,793 shares underlying pre-funded warrants were outstanding, respectively.

Previous wording

In February 2026, we completed an underwritten public offering of 12,650,000 shares of our common stock, which included the full exercise of the underwriters’ option to purchase an additional 1,650,000 shares, at a price of $50.00 per share. In aggregate, we received $601.8 million in net proceeds after deducting underwriting discounts, commissions and other offering expenses payable by us.

Current wording

In February 2026, we completed an underwritten public offering of 12,650,000 shares of our common stock, which included the full exercise of the underwriters’ option to purchase an additional 1,650,000 shares, at a price of $50.00 per share. In aggregate, we received $601.8 million in net proceeds after deducting underwriting discounts, commissions and other offering expenses payable by us. We did not have any public offerings during the three and nine months ended September 30, 2025.

Previous wording

Our primary uses of cash are to fund our operations, which consist primarily of research, development and manufacturing expenditures related to our programs and, to a lesser extent, capital expenditures for our commercial manufacturing facility build-out and general and administrative expenditures. We anticipate that we will continue to incur significant expenses and capital expenditures for the foreseeable future as we continue to advance our vaccine candidates, expand our corporate infrastructure, further our research and development initiatives for our vaccine candidates, build out and operate our commercial manufacturing facilities, and scale our laboratory and manufacturing operations. We are subject to all of the risks typically related to the development of new drug candidates, and we may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. We anticipate that we will need substantial additional funding in connection with our continuing operations.

Current wording

Our primary uses of cash are to fund our operations, which consist primarily of research, development and manufacturing expenditures related to our programs and, to a lesser extent, capital expenditures for our commercial manufacturing facility and general and administrative expenditures. We anticipate that we will continue to incur significant expenses and capital expenditures for the foreseeable future as we continue to advance our vaccine candidates, expand our corporate infrastructure, further our research and development initiatives for our vaccine candidates, build out and operate our commercial manufacturing facilities, and scale our laboratory and manufacturing operations. We are subject to all of the risks typically related to the development of new drug candidates, and we may encounter unforeseen expenses, difficulties, complications, delays and other unknown factors that may adversely affect our business. We anticipate that we will need substantial additional funding in connection with our continuing operations.

Previous wording

Net cash used in operating activities for the six months ended June 30, 2026 was $513.1 million, an increase of $225.7 million compared to the six months ended June 30, 2025. The increase was primarily due to higher cash expenditures to support our business growth, including increased development and manufacturing activities in connection with the adult and infant PCV programs to support the potential future commercial launches, as well as timing of payments.

Current wording

Net cash used in operating activities for the nine months ended September 30, 2026 was $737.2 million, an increase of $306.4 million compared to the nine months ended September 30, 2025. The increase was primarily due to higher cash expenditures to support our business growth, including increased development and manufacturing activities in connection with the adult and infant PCV programs to support the potential future commercial launches, as well as timing of payments.

Previous wording

Net cash used in investing activities for the six months ended June 30, 2026 was $85.7 million, an increase of $286.8 million compared to net cash provided by investing activities for the six months ended June 30, 2025. The change was primarily attributable to a $189.3 million increase in purchases of investments and a $114.6 million decrease in maturities and sales of investments.

Current wording

Net cash provided by investing activities for the nine months ended September 30, 2026 was $85.1 million, a decrease of $237.1 million compared to net cash provided by investing activities for the nine months ended September 30, 2025. The change was primarily attributable to a $170.3 million increase in purchases of investments and a $91.1 million decrease in maturities and sales of investments, which were partially offset by a $22.9 million decrease in cash used for purchases of manufacturing facility and equipment construction-in-progress.

Previous wording

Net cash provided by financing activities for the six months ended June 30, 2026 was $607.3 million, an increase of $604.0 million compared to the six months ended June 30, 2025. The increase was primarily due to $601.8 million in net proceeds from the follow-on offering during the six months ended June 30, 2026, whereas no such offerings occurred during the six months ended June 30, 2025.

Current wording

Net cash provided by financing activities for the nine months ended September 30, 2026 was $602.0 million, an increase of $602.4 million compared to the nine months ended September 30, 2025. The increase was primarily due to $601.8 million in net proceeds from the follow-on offering during the nine months ended September 30, 2026, whereas no such offerings occurred during the nine months ended September 30, 2025.

Previous wording

We have operating lease agreements for our office spaces. As of June 30, 2026, we had total lease payment obligations of $158.2 million, of which $13.7 million is payable within one year.

Current wording

We have operating lease agreements for our office spaces and a finance lease agreement for our manufacturing activities. As of September 30, 2026, we had total operating lease payment obligations of $154.6 million, of which $14.1 million is payable within one year. As of September 30, 2026, we had total finance lease payment obligations of $131.2 million, of which $14.9 million is payable within one year.