By the time Moderna and Pfizer apply to the US Food and Drug Administration for authorization for their coronavirus vaccines, there will likely be even more data to show how well the vaccines work, according to two doctors involved with the process.
On Monday, Pfizer announced that 94 participants in their Phase 3 clinical trial had become ill with Covid-19, and the vaccine was more than 90% effective.
Wednesday, Moderna announced that 53 participants in its trial had become ill, and efficacy data should be available by the end of the month.
By the time the two companies apply for emergency use authorizations from the FDA, many more participants will have become ill, giving an even clearer picture about how well the vaccine works.
“This is good news,” said Dr. Paul Offit, a member of the FDA’s Vaccines and Related Biological Products Advisory Committee, which will review the vaccine applications. “The more data the better.”
For example, by the time Pfizer sends its data to the FDA, there might be an additional 70 trial participants who will have become sick with Covid-19, instead of just the 94 announced on Monday, according to Dr. Larry Corey, who runs the Covid-19 Prevention Network created by the National Institutes of Health.
How it works, In the trials, half of the participants received the vaccine, and half the placebo, which is a shot of saline that does nothing. Months then went by while the participants were out in their communities, and some of them contracted Covid-19.
An independent board of experts then looks to see how many of the people who became ill received the vaccine and how many received the placebo, which tells you how effective the vaccine is.
More data also gives more information about how the vaccine works for particular subgroups, such as the elderly or racial minorities.
“It will ultimately help answer the question — will this work for me?” said Corey, a virologist at the Fred Hutchinson Cancer Research Center.
The reason so many more participants will develop Covid-19 is because rates in the US have been skyrocketing in recent weeks, Corey said.
Pfizer and Moderna will likely seek emergency use authorization from the US FDA for their coronavirus vaccines within the next few weeks, the Operation Warp Speed chief adviser said. If approved, vaccinations could begin in December, he said.
Coronavirus cases have grown exponentially across the United States just in the past week and it was necessary that “we need to mask up the entire country now,” Dr. Jonathan Reiner, CNN medical analyst, said Friday.
“The move should be a national mask mandate,” Reiner, who is a professor of medicine at George Washington University, told our reporter Erin Burnett. “The President should be on the phone with every governor tonight doing that.”