Pfizer Reaffirms Safety and Efficacy of COVID-19 Vaccines

Pfizer Reaffirms Safety and Efficacy of COVID-19 Vaccines

NEW YORK, Tuesday, September 16, 2025 - Pfizer Inc. (NYSE: PFE) today reaffirmed the safety and efficacy of the COVID-19 vaccine and posted resources supporting its impact on global health. These sources reflect the company's commitment to transparency and ensure the accessibility of the data. The evidence has previously been shared with regulatory authorities and presented in scientific forums, as well as published in peer-reviewed publications. For ease of reference, Pfizer posts both independent, real-world effectiveness and company-sponsored studies in the COVID-19 updates and research hub. These sources support the following findings:

• Global and United States (U.S.) impact of COVID-19 vaccines: COVID-19 vaccines saved over 14 million lives globally in the first year while also averting substantial economic losses¹. Between 2020-2024 during the pre-Omicron and Omicron periods, studies consistently estimated that COVID-19 vaccines averted millions of deaths globally^2,3. Recent data from the U.S. Centers for Disease Control and Prevention (CDC) for September 2023 to August 2024 reported COVID-19 vaccines prevented over 107,000 hospitalizations, 18,000 intensive care unit admissions, and 6,700 in-hospital deaths in the United States that year, with older adults achieving the largest averted burden of severe COVID-19^4,5,6.
• Pfizer-BioNTech vaccine effectiveness: The Pfizer-BioNTech vaccine has consistently provided strong protection against symptomatic and severe COVID-19 disease across multiple variants including Delta and Omicron and subvariants. Vaccine effectiveness varies by factors such as age and underlying conditions and remains substantial for older adults, healthcare workers, children, and immunocompromised individuals throughout the world^7,8.
• High population immunity: By the end of 2023, more than 95% of adults and 90% of children in the U.S. had been exposed to SARS-CoV-2 through infection, vaccination or both⁹, highlighting that a high proportion of the population had pre-existing immunity to SARS-CoV-2 in the 2024-2025 season. Consequently, vaccine effectiveness during the 2024-2025 season represents the added protection conferred by the latest COVID-19 vaccine formulation on top of pre-existing immunity.
• Protection against long COVID: Consistent evidence supports that COVID-19 vaccination received prior to SARS-CoV-2 infection reduces the risk of experiencing long COVID^{10,11,12,13,14,15,16,17,18,19,20,21}. Multiple peer-reviewed systematic reviews and meta-analyses showed that protection against long COVID has been observed in studies conducted during pre-Omicron and Omicron periods, using varying long COVID definitions, and across studies regardless of the proportion of patients experiencing severe acute illness (i.e., hospitalization)²⁰.
• Continued COVID-19 burden: The mRNA COVID-19 vaccines have consistently demonstrated significant vaccine effectiveness during the pandemic and post-pandemic periods, with the greatest protection against death and severe disease. Although the disease burden has declined since the pandemic peaks in early 2022^22,23, COVID-19 continues to cause substantial morbidity, mortality and consequences for healthcare systems. According to preliminary estimates by the CDC, between October 2024 and August 2025 in the U.S. there were 4.4 million COVID-19 outpatient visits, 350,000-510,000 COVID-19 hospitalizations, and 39,000-58,000 COVID-19 deaths²⁴.
• Recent vaccine effectiveness during 2024-2025 season: In a recent study, the latest Pfizer-BioNTech KP.2 vaccine showed 41-75% effectiveness (range based on age demographic, subject characteristics or time of follow-up after vaccination) against hospitalization and over 56% effectiveness against outpatient and emergency care visits in adults^25,26. Outside of the U.S. where the Pfizer-BioNTech JN.1 COVID-19 vaccine was available, the vaccine provided a high level of protection (>60%) against severe illness (ie, hospitalization and death) during the 2024-2025 season among older adults in Denmark²⁷.
• LP.8.1-adapted COVID-19 vaccine 2025-2026 formula: Pfizer and BioNTech recently shared Phase 3 clinical trial data from a cohort of adults 65 and older, and 18 to 64 with at least one underlying risk condition which shows, on average, at least a 4-fold increase in LP.8.1-neutralizing antibody titers after receiving the LP.8.1-adapted COVID-19 vaccine 2025-2026 formula.
• Recommendations for vaccination: Health authorities around the world continue to recommend eligible individuals receive updated COVID-19 vaccines to maintain optimal protection against COVID-19 and to best prevent long COVID, including in children^28,29.

"COVID-19 vaccines, especially the mRNA COVID-19 vaccines, have been instrumental in preventing millions of deaths and reducing severe illness worldwide during and after the pandemic," said Chris Boshoff, MD, PhD, Chief Scientific Officer and President, Research and Development at Pfizer. "Despite evolving virus variants, updated vaccine formulations have consistently protected against hospitalization, severe disease, and long COVID, reinforcing the need to sustain high vaccination coverage."

The Pfizer-BioNTech COVID-19 vaccine is available in more than 130 countries. The companies will continue to gather evidence on the risk-benefit profile of the vaccine and monitor the real-world impact of vaccination.

About Pfizer: Breakthroughs That Change Patients' LivesAt Pfizer, we apply science and our global resources to bring therapies to people that extend and significantly improve their lives. We strive to set the standard for quality, safety and value in the discovery, development and manufacture of health care products, including innovative medicines and vaccines. Every day, Pfizer colleagues work across developed and emerging markets to advance wellness, prevention, treatments and cures that challenge the most feared diseases of our time. Consistent with our responsibility as one of the world's premier innovative biopharmaceutical companies, we collaborate with health care providers, governments and local communities to support and expand access to reliable, affordable health care around the world. For 175 years, we have worked to make a difference for all who rely on us. We routinely post information that may be important to investors on our website at https://www.Pfizer.com. In addition, to learn more, please visit us on https://www.Pfizer.com and follow us on X at @Pfizer and @Pfizer News, LinkedIn, YouTube and like us on Facebook at Facebook.com/Pfizer.

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1 Watson OJ, Barnsley G, Toor J, et al. Global impact of the first year of COVID-19 vaccination: a mathematical modelling study. Lancet Infect Dis. 2022;22(9):1293-302.2 Sevilla JP, Burnes D, Knee JS, et al. The global health and economic value of COVID-19 vaccination. BMJ Glob Health. 2024;9(9).3 Ioannidis JPA, Pezzullo AM, Cristiano A, et al. Global Estimates of Lives and Life-Years Saved by COVID-19 Vaccination During 2020-2024. JAMA Health Forum. 2025;6(7):e252223.4 CDC. (2025). COVID-19 Vaccination Coverage and Intent for Vaccination, Children 6 months through 17 years, United States Updated 7 May 2025. Available from: https://www.cdc.gov/covidvaxview/weekly-dashboard/child-coverage-vaccination.html. Accessed: 10 September 2025.5 CDC. (2025). COVID-19 Vaccination Coverage and Intent for Vaccination, Adults 18 Years and Older, United States Updated 7 May 2025. Available from: https://www.cdc.gov/covidvaxview/weekly-dashboard/adult-vaccination-coverage.html. Accessed: 10 September 2025.6 Wiegand RE, Devine O, Wallace M, et al. Estimating COVID-19 associated hospitalizations, ICU admissions, and in-hospital deaths averted in the United States by 2023-2024 COVID-19 vaccination: A conditional probability, causal inference, and multiplier-based approach. Vaccine. 2025;49:126808. 7 International Vaccine Access Center (IVAC) JHBSoPHV-h. (2022). Results of COVID-19 Vaccine Effectiveness Studies: An Ongoing Systematic Review. Forest Plots: Vaccine Effectiveness against Delta and Omicron Variants of Concern Updated 12 May 2022. Available from: https://view-hub.org/sites/default/files/2022-06/COVID19%20VE%20Studies_Forest%20Plots_Delta_Omicron_01Jun2022_Archived.pdf. Accessed: 10 September 2025. 8 International Vaccine Access Center (IVAC) JHBSoPHV-h. (2025). Results of COVID-19 Vaccine Effectiveness Studies: An Ongoing Systematic Review. Forest Plots: Vaccine Effectiveness against Omicron Variant of Concern Updated 29 August 2025. Available from: https://view-hub.org/sites/default/files/2025-08/COVID19%20VE%20Studies_Forest%20Plots_Omicron.pdf. Accessed: 10 September 2025.9 CDC. (2025). Antibody Seroprevalence Updated 5 September 2025. Available from: https://www.cdc.gov/covid/php/antibody-seroprevalence/index.html. Accessed: 10 September 2025.10 ECDC. (2025). Does COVID-19 vaccination reduce the risk and duration of post COVID-19 condition? Available from: https://www.ecdc.europa.eu/en/publications-data/does-covid-19-vaccination-reduce-risk-and-duration-post-covid-19-condition. Accessed: 10 September 2025.11 Watanabe A, Iwagami M, Yasuhara J, et al. Protective effect of COVID-19 vaccination against long COVID syndrome: A systematic review and meta-analysis. Vaccine. 2023;41(11):1783-90.12 Chow NKN, Tsang CYW, Chan YH, et al. The effect of pre-COVID and post-COVID vaccination on long COVID: A systematic review and meta-analysis. J Infect. 2024;89(6):106358.13 Gao P, Liu J, Liu M. Effect of COVID-19 Vaccines on Reducing the Risk of Long COVID in the Real World: A Systematic Review and Meta-Analysis. Int J Environ Res Public Health. 2022;19(19). 14 Hamad Saied M, van der Griend L, van Straalen JW, et al. The protective effect of COVID-19 vaccines on developing multisystem inflammatory syndrome in children (MIS-C): a systematic literature review and meta-analysis. Pediatr Rheumatol Online J. 2023;21(1):80.15 Man MA, Rosca D, Bratosin F, et al. Impact of Pre-Infection COVID-19 Vaccination on the Incidence and Severity of Post-COVID Syndrome: A Systematic Review and Meta-Analysis. Vaccines (Basel). 2024;12(2).16 Marra AR, Kobayashi T, Callado GY, et al. The effectiveness of COVID-19 vaccine in the prevention of post-COVID conditions: a systematic literature review and meta-analysis of the latest research. Antimicrob Steward Healthc Epidemiol. 2023;3(1):e168.17 Marra AR, Kobayashi T, Suzuki H, et al. The effectiveness of coronavirus disease 2019 (COVID-19) vaccine in the prevention of post-COVID-19 conditions: A systematic literature review and meta-analysis. Antimicrob Steward Healthc Epidemiol. 2022;2(1):e192.18 Mumtaz A, Sheikh AAE, Khan AM, et al. COVID-19 Vaccine and Long COVID: A Scoping Review. Life (Basel). 2022;12(7).19 Notarte KI, Catahay JA, Velasco JV, et al. Impact of COVID-19 vaccination on the risk of developing long-COVID and on existing long-COVID symptoms: A systematic review. EClinicalMedicine. 2022;53:101624.20 Rudolph AE, Al Akoury N, Bogdanenko N, et al. Factors affecting the impact of COVID-19 vaccination on post COVID-19 conditions among adults: A systematic literature review. Hum Vaccin Immunother. 2025;21(1):2474772.21 Tsampasian V, Elghazaly H, Chattopadhyay R, et al. Risk Factors Associated With Post-COVID-19 Condition: A Systematic Review and Meta-analysis. JAMA Intern Med. 2023;183(6):566-80.22 CDC. (2025). COVID-19 Surveillance Data in the United States Updated 5 September 2025. Available from: https://www.cdc.gov/covid/php/surveillance/index.html. Accessed: 10 September 2025.23 CDC. (2025). COVID-NET Updated 5 June 2025. Available from: https://www.cdc.gov/covid/php/covid-net/index.html. Accessed: 10 September 2025.24 CDC. (2024). Preliminary Estimates of COVID-19 Burden for 2024-2025 Updated 6 December 2024. Available from: https://www.cdc.gov/covid/php/surveillance/burden-estimates.html. Accessed: 10 September 2025.25 Andersen KM, Ahi T, Mateus JS, et al. 2024-2025 BNT162b2 COVID-19 vaccine effectiveness in non-immunocompromised adults: mid-season estimates from vaccine registries in two states linked to administrative claims. Vaccine. 2025;62:127534.26 Appaneal HJ, Lopes VV, Puzniak L, et al. Early effectiveness of the BNT162b2 KP.2 vaccine against COVID-19 in the US Veterans Affairs Healthcare System. Nat Commun. 2025;16(1):4033.27 Hansen CH, Lassauniere R, Rasmussen M, et al. Effectiveness of the BNT162b2 and mRNA-1273 JN.1-adapted vaccines against COVID-19-associated hospitalisation and death: a Danish, nationwide, register-based, cohort study. Lancet Infect Dis. 2025;10.1016/S1473-3099(25)00380-9. 28 CDC. (2025). Staying Up to Date with COVID-19 Vaccines Updated 6 June 2025. Available from: https://www.cdc.gov/covid/vaccines/stay-up-to-date.html. Accessed: 10 September 2025. 29 CDC. (2025). Long COVID Basics Updated 24 July 2025. Available from: https://www.cdc.gov/long-covid/about/index.html. Accessed: 10 September 2025.

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