The mRNA-based vaccine candidate, BNT162b2, was found to be more than 90% effective in preventing coronavirus disease 2019 (COVID-19) in participants without evidence of prior severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, according to phase 3 trial data announced by Pfizer and BioNTech.

BNT162b2 is a nucleoside-modified messenger RNA (modRNA) vaccine that encodes an optimized SARS-CoV-2 full-length spike protein antigen. The investigational vaccine emerged as the strongest candidate based on data demonstrating robust immune response and overall tolerability. 

The phase 3 trial is investigating a 2-dose series in which the vaccine is administered intramuscularly 21 days apart. Among the 43,538 participants currently enrolled in the study, 38,955 have received a second dose. 

On November 8th, an independent data monitoring committee (DMC) evaluated 94 confirmed cases of COVID-19 among the trial participants. Results showed that the vaccine was found to be greater than 90% effective based on the breakdown of cases in the vaccine and placebo arms, at 7 days after the second dose. Additionally, no serious safety concerns were noted, according to the DMC. The trial will continue as planned and final analysis is expected when the number of confirmed COVID-19 cases reaches 164.

“The first set of results from our phase 3 COVID-19 vaccine trial provides the initial evidence of our vaccine’s ability to prevent COVID-19,” said Dr. Albert Bourla, Pfizer Chairman and CEO. “We look forward to sharing additional efficacy and safety data generated from thousands of participants in the coming weeks.”

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According to the Companies, an Emergency Use Authorization will likely be submitted to the Food and Drug Administration by the third week of November once the required safety milestone has been achieved. Manufacturing efforts are already increasing to keep up with potential demand. If approved, the Companies expect to produce up to 50 million doses by the end of 2020 and possibly more than 1.3 billion doses by the end of 2021.


Pfizer and BioNTech announce vaccine candidate against COVID-19 achieved success in first interim analysis from phase 3 study. [press release]. November 9, 2020.