The Pfizer-BioNTech and Moderna Coronavirus vaccines are robustly effective in preventing infections in real-life conditions, according to a federal study released Monday that provides reassurance of protection for front-line workers.
In a study done in the United States of about 4,000 health-care personnel, police, firefighters and other essential workers, the Centers for Disease Control and Prevention found that the vaccines reduced the risk of infection by 80 percent after one shot. Protection increased to 90 percent following the second dose.
The findings are consistent with clinical trial results and studies showing strong effectiveness in Israel and the United Kingdom, and in initial studies of health-care workers at the UT Southwestern Medical Center and in Southern California.
The CDC report is significant, experts said, because it analyzed how well the vaccines worked among a diverse group of front-line working-age adults whose jobs make them more likely to be exposed to the virus and to spread it.
The frontline workers received vaccinations between mid-December, when the doses first became available, to mid-March, a 13-week period that included the deadly winter surge that was killing more than 3,000 people daily by January.
The study is also one of the first to estimate vaccine effectiveness among participants against infection — rather than just monitoring for symptomatic cases — including infections that did not result in symptoms, according to the CDC.
Among 2,479 fully vaccinated people, just three had confirmed infections. Among 477 people who received one dose, eight infections were reported.
By comparison, among 994 people who were not vaccinated, 161 developed infections.
No deaths were reported.
CDC Director Rochelle Walensky said the study shows national vaccination efforts are working.
(With input from The Washington Post)