Posted November 9, 2020
On Monday, drug maker Pfizer announced that an early analysis of its COVID-19 vaccine trial was shown to be more than 90% effective in preventing the virus among trial volunteers who had not been previously infected.
Pfizer developed the vaccine with German drugmaker BioNTech. Few details from its clinical trial were made public, but were based on the first formal review of the data by an outside panel of experts.
The data was released by Pfizer in a news release, not a peer-reviewed medical journal. It is not conclusive evidence that the vaccine is safe and effective, and the initial finding of more than 90 percent efficacy could change as the trial goes on. It is expected to continue until 164 people in the 44,000-person trial have developed COVID-19. Half of the participants received two doses of the vaccine, and half received a placebo. The first analysis was based on 94 volunteers who developed COVID-19, but Pfizer did not say how many of those cases came from participants who had received the vaccine. The trial will also evaluate how well it protects against developing severe forms of the disease, and how well the vaccine protects people who have already been infected with the coronavirus.
Pfizer will continue to collect the recommended two months of safety data before asking the Food and Drug Administration for emergency authorization of the two-dose vaccine. Company executives said it will have manufactured enough doses to immunize 15 to 20 million people by the end of the year.
Eleven other vaccines are currently in late stage trials.