Pfizer, BioNTech Confirm High Efficacy, No Serious Safety Concerns in Updated Topline Analysis of COVID-19 Vaccine

April 2, 2021
Aislinn Antrim, Associate Editor

The Pfizer and BioNTech vaccine was 100% effective in preventing COVID-19 cases in South Africa, where the B.1.351 variant is prevalent.

An updated analysis of Pfizer and BioNTech’s COVID-19 vaccine found high efficacy and no serious safety concerns through up to 6 months following the second dose, according to a press release.

Results from the analysis of 46,307 trial participants confirm earlier data and demonstrate strong protection. Of the 927 confirmed symptomatic cases of COVID-19, 850 were in the placebo group and 77 cases were in the vaccinated group, demonstrating a vaccine efficacy of 91.3%.

Furthermore, the vaccine was 100% effective in preventing severe disease as defined by the CDC and 95.3% effective in preventing severe disease as defined by the FDA. Additionally, it was 100% effective in preventing COVID-19 cases in South Africa, where the B.1.351 variant is prevalent. The study in South Africa enrolled 800 participants and researchers observed 9 cases of COVID-19, all in the placebo group.

“These data confirm the favorable efficacy and safety profile of our vaccine and position us to submit a Biologics License Application to the US FDA,” said Albert Bourla, DVM, PhD, chairman and chief executive officer of Pfizer, in the press release. “The high vaccine efficacy observed through up to 6 months following a second dose and against the variant prevalent in South Africa provides further confidence in our vaccine’s overall effectiveness.”

The safety of the vaccine has now been evaluated in more than 44,000 participants aged 16 years and older, with more than 12,000 vaccinated participants having at least 6 months follow-up after their second dose. Efficacy was generally consistent across age, gender, race, and ethnicity demographics, and across participants with a variety of underlying conditions. Adverse effects were consistent with previously reported results.

“It is an important step to further confirm the strong efficacy and good safety data we have seen so far, especially in a longer-term follow-up,” said Ugur Sahin, MD, CEO and co-founder of BioNTech, in the press release. “These data also provide the first clinical results that a vaccine can effectively protect against currently circulating variants, a critical factor to reach herd immunity and end this pandemic for the global population.”

REFERENCE

Pfizer and BioNTech Confirm High Efficacy and No Serious Safety Concerns Through Up to Six Months Following Second Dose in Updated Topline Analysis of Landmark COVID-19 Vaccine Study [news release]. Pfizer; April 1, 2021. https://www.pfizer.com/news/press-release/press-release-detail/pfizer-and-biontech-confirm-high-efficacy-and-no-serious. Accessed April 2, 2021.