Pfizer: Early Data Shows 90% COVID-19 Vaccine Effectiveness

Pfizer has reported that its SARS-CoV-2 vaccine candidate appears to be more than 90% effective at preventing COVID-19, following the first interim efficacy analysis of results from the phase 3 trial.

The phase 3 trial, which began in late July 2020, currently has 43,538 enrollees, 38,955 of whom have received a second dose of the vaccine as of November 8, 2020. Following discussions with the FDA, Pfizer elected to update the 32-case interim analysis to occur after a minimum of 62 cases of COVID-19 had been identified. Following discussions, 94 cases were available for analysis.

Overall, they found a vaccine efficacy rate above 90% at 7 days following the second dose, meaning that protection occurs at 28 days after initiation of the 2-dose vaccination regimen.

No serious safety concerns have been reported. Pfizer noted that following additional analysis, the efficacy percentage of the vaccine could vary. The final analysis will occur at 164 confirmed cases, and submission for Emergency Use Authorization to the FDA is planned to occur following the achievement of the required safety milestone, expected in the 3rd week of November 2020.

“Today is a great day for science and humanity, said Albert Bourla, DVT, PhD, chairman and CEO of Pfizer. 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.

“With today’s news, we are a significant step closer to providing people around the world with a much-needed breakthrough to help bring an end to this global health crisis. We look forward to sharing additional efficacy and safety data generated from thousands of participants in the coming weeks.”

—Michael Potts

Reference:

Pfizer and BioNTech announce vaccine candidate against COVID-19 achieved success in first interim analysis from phase 3 study. News release. November 9, 2020. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-announce-vaccine-candidate-against

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