The U.S. government’s first look at the real-world use of COVID-19 vaccines found their effectiveness was nearly as robust as it was in controlled studies.
The two vaccines available since December — Pfizer and Moderna — were highly effective at 90% after two doses, the Centers for Disease Control and Prevention reported Monday. In testing, the vaccines were about 95% effective in preventing COVID-19.
“This is very reassuring news,” said the CDC’s Mark Thompson, the study’s lead author. “We have a vaccine that’s working very well.”
The study is the government’s first assessment of how the shots have been working beyond the drugmakers’ initial experiments. Results can sometimes change when vaccines are used in larger, more diverse populations outside studies.
With nearly 4,000 participants from six states, the study focused on health care workers, first responders and other front-line workers who had first priority for the shots because they are at higher risk. They were given nasal swab test kits to use every week to check for signs of a coronavirus infection.