CDC: Moderna and Pfizer Vaccines Are Highly Effective in Real-World Conditions

Gina Kolata, reporting for 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.

This is just amazingly good news all around. The vaccines don’t just prevent the vaccinated from getting sick, but they almost certainly stop asymptomatic spread, too. And the 4,000 people chosen for the CDC study were at high risk, because they’re front-line health care workers and first responders. For those of us at lower risk, the results should be even better.

See also: County-level map of vaccination rates across the U.S.

★ Monday, 29 March 2021