What is the BNT-162b2 coronavirus disease 2019 (COVID-19) vaccine?

Updated: Sep 24, 2021
  • Author: David J Cennimo, MD, FAAP, FACP, FIDSA, AAHIVS; Chief Editor: John L Brusch, MD, FACP  more...
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  • Rolling BLA submitted May 7, 2021 to FDA for full approval for individuals aged 16 years and older
  • EUA granted in the United States for individuals aged 12 years and older 
  • NIH  phase 2 trial of allergic reactions to vaccine in participants with severe allergies underway 
  • Phase 3 trials complete in adults and adolescents aged 12 years and older
  • Phase 2/3 trial in pregnant women started in February 2021
  • Phase 1/2/3 trials starting spring 2021 in infants and children aged 6 months and older
  • Phase 3 trial in older adults of BNT-162b2 booster dose followed by 20-valent pneumococcal conjugate vaccine (20vPnC) 

BNT-152b2 (Pfizer) is a nucleoside-modified messenger RNA (modRNA) vaccine (BioNTech and Pfizer) that encodes an optimized SARS-CoV-2 receptor-binding domain (RBD) antigen. It is a 2-dose series given 21 days apart. 

A multinational phase 3 trial included randomly assigned 43,448 participants to receive vaccine or placebo (vaccine group, 21,720; placebo group, 21,728) by injection. Approximately 42% of global participants and 30% of US participants were of racially and ethnically diverse backgrounds, and 41% of global and 45% of US participants were 56-85 years of age.

Vaccine efficacy was 95% against the original SARS-CoV-2 strain at 7 days after dose 2, and no serious safety concerns were observed. There were 170 confirmed cases (placebo group, 162; vaccine group, 8); 10 severe cases occurred after the first dose (placebo group, 9; vaccine group, 1). The only grade 3 adverse event with a frequency of greater than 2% was fatigue at 3.8%; headache occurred in 2% of participants. Short-term mild-to-moderate pain at the injection site was the most common reaction, and severe pain occurred in less than 1% of participants across all age groups.7 

Efficacy data in an ongoing, real-world, phase 3 assessment of 46,307 participants showed 91.3% efficacy against COVID-19, when gauged as cases 7 days to 6 months after the second vaccine dose. Among 927 confirmed symptomatic COVID-19 cases, 850 were in the placebo group compared with 77 in the vaccine group. It was 100% effective in preventing severe disease (Centers for Disease Control and Prevention [CDC] definition). All 32 severe disease cases occurred in the placebo group. [14]

Results from an observational study of real-world data from healthcare workers (HCWs) employed in a large medical center in Israel after their first vaccine dose have been published. Among 9109 eligible staff, 7214 (79%) received a first dose and 6037 (66%) received the second dose in December 2020 and January 2021. Compared with a symptomatic COVID-19 rate of 5 per 10,000 person-days in unvaccinated HCWs, disease rates were 2.8 and 1.2 per 10,000 person-days on days 1-14 and days 15-28 after the first vaccine dose, respectively. Adjusted rate reductions of COVID-19 disease were 47% for days 1-14 and  85% for days 15-28 after the first dose. [15]  

In another observational study, researchers used integrated data repositories in Israel’s largest health care organization to evaluate mass immunization effectiveness. The 5 outcomes evaluated were documented SARS-CoV-2 infection, symptomatic Covid-19, hospitalization, severe illness, and death. The observations suggest the vaccine is effective for a wide range of COVID-19–related related outcomes that are consistent [16] with the randomized trial by Polack et al. [13]  

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