Pfizer final analysis of Phase 3 study indicates COVID-19 vaccine efficacy rate of 95%

Photo: Twitter/@pfizer

NEW YORK: The Pfizer and BioNTech on Wednesday (November 18, 2020) announced that after conducting the final efficacy analysis in the Phase 3 study, their COVID-19 vaccine, BNT162b2, met all of the study’s primary efficacy endpoints. They said that the analysis of the data indicates a vaccine efficacy rate of 95% in participants without prior SARS-CoV-2 infection (first primary objective) and also in participants with and without prior SARS-CoV-2 infection (second primary objective), in each case measured from 7 days after the second dose. 

"The first primary objective analysis is based on 170 cases of COVID-19, as specified in the study protocol, of which 162 cases of COVID-19 were observed in the placebo group versus 8 cases in the BNT162b2 group. Efficacy was consistent across age, gender, race and ethnicity demographics. The observed efficacy in adults over 65 years of age was over 94%," said Pfizer.

The study reached 170 confirmed cases of #COVID19, with the #vaccine candidate BNT162b2 demonstrating 95% efficacy beginning 28 days after the first dose. — Pfizer Inc. (@pfizer) November 18, 2020

There were 10 severe cases of COVID-19 observed in the trial, with nine of the cases occurring in the placebo group and one in the BNT162b2 vaccinated group.

Pfizer stated that to date, the Data Monitoring Committee for the study has not reported any serious safety concerns related to the vaccine. 

"A review of unblinded reactogenicity data from the final analysis which consisted of a randomized subset of at least 8,000 participants 18 years and older in the phase 2/3 study demonstrates that the vaccine was well tolerated, with most solicited adverse events resolving shortly after vaccination. The only Grade 3 (severe) solicited adverse events greater than or equal to 2% in frequency after the first or second dose was fatigue at 3.8% and headache at 2.0% following dose 2. Consistent with earlier shared results, older adults tended to report fewer and milder solicited adverse events following vaccination," added Pfizer.

The companies announced that the safety milestone required by the US Food and Drug Administration (FDA) for Emergency Use Authorization (EUA) has been achieved and the Pfizer and BioNTech plan to submit a request within days to the FDA for a EUA based on the totality of safety and efficacy data collected to date, as well as manufacturing data relating to the quality and consistency of the vaccine. 

Within days, we plan to submit a request to the @US_FDA for an EUA based on the totality of safety and efficacy data collected, as well as manufacturing data relating to the quality and consistency of the vaccine candidate. — Pfizer Inc. (@pfizer) November 18, 2020

"The study results mark an important step in this historic eight-month journey to bring forward a vaccine capable of helping to end this devastating pandemic. We continue to move at the speed of science to compile all the data collected thus far and share with regulators around the world," said Dr Albert Bourla, Pfizer Chairman and CEO. 

He added, "With hundreds of thousands of people around the globe infected every day, we urgently need to get a safe and effective vaccine to the world."

"We are grateful that the first global trial to reach the final efficacy analysis mark indicates that a high rate of protection against COVID-19 can be achieved very fast after the first 30 µg dose, underscoring the power of BNT162 in providing early protection," said Ugur Sahin, M.D., CEO and Co-founder of BioNTech. 

He added, "These achievements highlight the potential of mRNA as a new drug class. Our objective from the very beginning was to design and develop a vaccine that would generate rapid and potent protection against COVID-19 with a benign tolerability profile across all ages. We believe we have achieved this with our vaccine candidate BNT162b2 in all age groups studied so far and look forward to sharing further details with the regulatory authorities. I want to thank all the devoted women and men who contributed to this historically unprecedented achievement. We will continue to work with our partners and governments around the world to prepare for global distribution in 2020 and beyond."

This is to be noted that the Phase 3 clinical trial of BNT162b2 began on July 27 and has enrolled 43,661 participants to date, 41,135 of whom have received a second dose of the vaccine candidate as of November 13, 2020. 

Approximately 42% of global participants and 30% of U.S. participants have racially and ethnically diverse backgrounds, and 41% of global and 45% of U.S. participants are 56-85 years of age. A breakdown of the diversity of clinical trial participants can be found here from approximately 150 clinical trials sites in the United States, Germany, Turkey, South Africa, Brazil and Argentina.

"The trial will continue to collect efficacy and safety data in participants for an additional two years," said Pfizer.

They stated that based on current projections, Pfizer and BioNTech expect to produce globally up to 50 million COVID-19 vaccine doses in 2020 and up to 1.3 billion coronavirus doses by the end of 2021.