Moderna's chief medical officer said he became emotional when he saw the data Saturday night
"It was the first time I allowed myself to cry," Dr. Tal Zaks said. "We have a full expectation to change the course of this pandemic."
Moderna will become the second company to apply to the FDA for emergency use authorization for a coronavirus vaccine. Pfizer applied on November 20
with data showing similarly high efficacy.
The FDA will meet with its advisory committee in December to review Pfizer's and Moderna's applications.
The first vaccinations in the United States are expected to take place "towards the latter part of December," according to Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
Moderna said it also plans to apply for authorization from the European Medicines Agency on Monday.
Moderna's new data
On Monday, Moderna released updated efficacy data for its Phase 3 clinical trial.
Starting in July, Moderna gave either its vaccine or a placebo -- a shot of saline that does nothing -- to some 30,000 people in the United States. With high rates of coronavirus throughout the country over the next following months, many of those study subjects developed Covid-19.
But there was a big difference between the group that got the vaccine and the group that got the placebo.
Among the approximately 15,000 people who received the vaccine, 11 developed Covid-19.
Among the approximately 15,000 people who received the placebo, 185 developed Covid-19.
That amounts to a 94.1% efficacy for Moderna's vaccine.
None of the 11 people who received the vaccine became severely ill, but 30 of the 185 who received the placebo became severely ill, and one of them died.
The vaccine had similar efficacy rates for elderly people and for people in racial minority groups, Zaks said.
In Pfizer's Phase 3 clinical trial, the vaccine proved to be 95% effective, and one study participant who received the vaccine developed a severe case of Covid-19.
While the two vaccines are not identical, both Pfizer and Moderna use messenger RNA to elicit an immune response in the human body. The vaccines are given in two doses a few weeks apart, and can cause side effects, such as a fever or body aches for a few days.
The FDA is scheduled to meet with its Vaccines and Related Biological Products Advisory Committee on December 10 to review Pfizer's application and on December 17 to review Moderna's application.
Offit, who is a member of that panel, said it will be important to look and see why some people still got Covid-19 even after being vaccinated.
"Were they more likely to be older? Were they more likely to be African-American or obese or have underlying medical problems like diabetes?" said Offit, a vaccine expert at the University of Pennsylvania.
If the FDA grants the vaccine emergency use authorization -- and it's expected that it will -- within a day or two, an advisory committee to the US Centers for Disease Control and Prevention will make a recommendation about who should get the shots first. That group will likely include health care workers and nursing home residents.