What is the Pfizer-Biotech (BNT162b2) COVID-19 vaccine?

Updated: Jan 12, 2021
  • Author: Setu K Patolia, MD, MPH; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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The initial phase 1 trial reporting the efficacy of BNT162b2, a lipid nanoparticle–formulated, modified RNA particle encoding the SARS-CoV2 full-length spike was published in the New England Journal of Medicine in December 2020. [62] Since then, the vaccine, which was administered as two 30-μg doses given 21 days apart, demonstrated 95% efficacy. From July 2020 to November 2020, 43,448 patients were randomized in a 1:1 distribution at 150 sites worldwide. Demographically, these cohorts included 51% males and 82.9% Whites. Also of note, approximately 58% of the patients were aged 16-58 years. Currently, 37,706 patients are at least 2 months post receiving the second dose, and adverse events up to 14 days after the second data were described. [63] These data were self-reported by means of an electronic diary and subdivided into local or systemic adverse events. More patients in the vaccine group reported adverse events (27% vs 12%). Further, four patients in the vaccine group reported severe adverse events necessitating withdrawal from the trial. Two patients in the vaccine group and four in the placebo died, but these were thought to be unrelated to the effects of the vaccine. Interestingly, there were no COVID-19–related deaths in either cohort.

Based on these data, the FDA issued an Emergency Use Authorization for the vaccine on December 11, 2020.

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