COVID-19 vaccines prevent 90 percent of all infections, CDC study says

Even as the CDC director was talking about the risk of a new surge, the agency published a new study using real-world data that showed both mRNA vaccines prevent coronavirus disease and infection, including asymptomatic and pre-symptomatic infections.

A study of about 4,000 health-care personnel, police, firefighters and other essential workers, showed both vaccines prevented 90 percent of infections two weeks after receiving the second of two doses.

Following a single dose of either vaccine, the participants’ risk of infection with SARS-CoV-2 was reduced by 80 percent two or more weeks after vaccination.

The findings are consistent with clinical trial results, as well as with other real-world studies in the U.K. and Israel.

Really good news: It’s a significant finding, as this was one of the first studies looking at infection, rather than just disease. It also analyzed how the vaccines work in a wide variety of front-line personnel— the people most at risk of spreading the virus. Preventing both asymptomatic and pre-symptomatic infections among health care workers and other essential workers through vaccination can help prevent the spread of COVID-19 to those they care for or serve.

Not quite freedom: Health officials were quick to note that while it’s excellent news for the people who have been vaccinated, there are still many more unvaccinated people, and the impact of vaccines on different variants is not known. Scientists are also still unsure how long protection lasts.