BNT162b2 mRNA vaccine for COVID-19 prevention [Classics Series]

This study summary is an excerpt from the book 2 Minute Medicine’s The Classics in Medicine: Summaries of the Landmark Trials

1. This clinical trial determined the efficacy of the BNT162b2 mRNA vaccine at preventing coronavirus disease 2019 (COVID-19) infection (94.6%) based on comparison to a placebo control group.

2. Rates of serious adverse events did not differ significantly between the BNT162b2 vaccine and control groups.

Original Date of Publication: December 2020

Study Rundown: This clinical efficacy trial compared COVID-19 infection rates of patients receiving the BNT162b2 mRNA vaccine and of those receiving a placebo control. Participants in the streatment group had significantly reduced COVID-19 infection rates when compared to those receiving placebo controls. Vaccine efficacy did not vary based on demographic subgroup analysis. Overall adverse events were higher in the BNT162b2 group, but serious adverse event rates did not differ significantly between groups. The present study has limited generalizability to certain higher risk populations, including children,pregnant individuals and immunocompromised individuals as they were not studied. These groups are commonly excluded from initial safety and efficacy trials to minimize confounding risk factors. In summary, this study demonstrates that the BNT162b2 mRNA vaccine provided a high-degree of COVID-19 protection with limited risk of serious adverse events.

Click to read the study in NEJM

In-Depth [randomized control trial]: This efficacy and safety trial randomized COVID-19 naïve participants to receive two doses of either the BNT162b2 mRNA vaccine (n = 21 720) or a placebo control (n = 21 728). Injections were given intramuscularly 21 days apart in both groups to adults aged 16 years or older. BNT162b2 mRNA vaccine efficacy was measured using rates of COVID-19 infection at least one week following second dose and was found to be 95% (95%CI 90.3-97.6). With only one dose, vaccine efficacy was 52% (95%CI 29.5-68.4). The safety profile of the BNT162b2 vaccine was measured at two-month follow-up. A higher rate of adverse events was reported in the intervention group (27%) as compared to the control group (12%). Serious adverse events did not differ significantly between groups, although safety monitoring will continue for two years after baseline.

Polack FP, Thomas SJ, Kitchin N, Absalon J, Gurtman A, Lockhart S, et al. Safety and Efficacy of the BNT162b2 mRNA COVID-19 Vaccine. N Engl J Med. 2020 Dec 31;383(27):2603–15.

©2022 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.