The New York Times:
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. […]
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 is likely rare, too.
There also has been concern that variants may render the vaccines less effective. The study’s results do not confirm that fear. Troubling variants were circulating during the time of the study — from December 14, 2020 to March 13, 2021 — yet the vaccines still provided powerful protection.
The vaccines don’t just prevent the vaccinated from getting sick, but they almost certainly stop asymptomatic spread, too. This is great news as we look forward to returning to normal. Now the challenge will be to get everyone to take the vaccine.