Consistent with clinical trial data, a two-dose regimen prevented 90 percent of infections by two weeks after the second shot. One dose prevented 80 percent of infections by two weeks after vaccination. …
The coronavirus vaccines made by Moderna and Pfizer-BioNTech are proving highly effective at preventing symptomatic and asymptomatic infections under real-world conditions, federal health researchers reported on Monday.
Consistent with clinical trial data, a two-dose regimen prevented 90 percent of infections by two weeks after the second shot. One dose prevented 80 percent of infections by two weeks after vaccination.
The news arrives even as the nation rapidly broadens eligibility for vaccines, and the average number of daily shots continues to rise. The seven-day average of vaccines administered hit 2.76 million on Monday, an increase over the pace the previous week, according to the Centers for Disease Control and Prevention.
But the virus may be gaining renewed momentum. According to a New York Times database, the seven-day average of new virus cases as of Sunday was 63,000, an increase of more than 16 percent over the past two weeks.
Similar upticks over the summer and winter led to major surges in the spread of disease, Dr. Rochelle Walensky, director of the Centers for Disease Control and Prevention, said at a news briefing on Monday. She said she had a sense of “impending doom” about a possible fourth surge of the virus.
The nation has “so much reason for hope,” she said. “But right now I’m scared.”
Scientists have debated whether vaccinated people may still get asymptomatic infections and transmit the virus to others. The new study, by researchers at the C.D.C., suggested that since infections were so rare, transmission was likely rare, too.
There also has been concern that variants may render the vaccines less effective. The study’s results
