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Studies to Address Emerging Variants

Third Dose of BNT161b2 and Ongoing Variant Vaccine Updates

As the SARS-CoV-2 virus continues to evolve and the pandemic rages in many places, Pfizer and BioNTech are continuing with our work to understand long term immunity, the potential need for booster shots, and any threat from circulating or new variants of concern on vaccine protection. We are taking a multi-pronged scientific approach to gather data and be prepared if needed with an updated vaccine.

1) Ongoing boosting studies
Pfizer and BioNTech initiated a global Phase 3 clinical study in July 2021 in the United States, Brazil, and South Africa, to evaluate a third booster dose of its COVID-19 vaccine (BNT162b2) on immunity against COVID-19 caused by the circulating and potential newly emerging SARS-CoV-2 variants. The Phase 3 study, which plans to enroll 10,000 participants who participated in the landmark Phase 3 trial, will evaluate the safety, tolerability, and efficacy of a third, booster dose of the COVID-19 vaccine compared to placebo.

This Phase 3 study builds on efforts we started back in February to gain an early understanding of the safety and immunogenicity of a third dose of BNT162b2.

2) Efforts against variants of concern
While Pfizer and BioNTech believe a third dose of their COVID-19 vaccine has the potential to preserve the highest levels of protective efficacy against all currently known variants, the Companies are remaining vigilant and are developing updated versions of the Pfizer-BioNTech COVID-19 vaccine to potentially address specific variants. The Companies are studying a Beta-variant-specific construct, the results of which are meant to establish a regulatory pathway for any updated vaccine that might be needed to address any future variant of potential concern, as well as a Delta-variant-specific construct. The Companies anticipate the clinical studies for the Delta-variant-specific construct to begin in August 2021, subject to regulatory approvals.

We are constantly conducting surveillance efforts focused specifically on monitoring for neutralization of emerging variants. You can learn more about the findings from this ongoing work under peer-reviewed publications.