Clinical trial data for the COVID-19 vaccine Pfizer is developing with BioNTech shows the candidate can prevent more than 90 percent of infections, the drugmaker said Nov. 9.
The results are based on an interim analysis of a trial in which 94 participants, half of whom received a placebo and half of whom received a vaccine, contracted COVID-19. Pfizer will continue the trial until 164 COVID-19 cases occur in order to gather more data and determine the candidate’s performance against other study endpoints.
Pfizer plans to collect two months of safety follow-up data, a key requirement laid out by the FDA before it grants emergency use authorization. That data is expected to be gathered by the third week of November, and if it raises no concerns, the drugmaker could apply for emergency use authorization by the end of the month. An accelerated review of the vaccine is underway in the U.K.
"This is about the best the news could possibly be for the world and for the United States and for public health," William Gruber, Pfizer's senior vice president for vaccine clinical research and development, told Bloomberg, saying the findings were better than even the best result he had wished for.
Analysis has not yet been conducted on the vaccine's efficacy among key subgroups, such as older patients. Pfizer also has not yet studied how the vaccine prevents severe cases of COVID-19.