CDC finds Pfizer, Moderna vaccines to be 94 percent effective in health workers 

The CDC’s ongoing largest effectiveness study found the Pfizer-BioNTech and Moderna COVID-19 vaccines to be 94 percent effective among health care workers.

The interim study results released on Friday further support previous data on the effectiveness of the two vaccines, which use mRNA technology and have been widely administered in the U.S.

The researchers estimated that those who were fully vaccinated were 94 percent less likely to develop symptomatic COVID-19, while people who were partially vaccinated were 82 percent less likely.

The study examined 1,843 health care professionals between January and March of this year after most workers in the field were given priority to get the vaccine early in the country’s rollout.

Why it’s important: The CDC research involved a sample size that reached a broader geographic area than the clinical trials with a network covering health care workers in 33 sites across 25 states.

“This report provided the most compelling information to date that COVID-19 vaccines were performing as expected in the real world,” Director Rochelle Walensky said in a statement. “This study, added to the many studies that preceded it, was pivotal to CDC changing its recommendations for those who are fully vaccinated against COVID-19.”

The study backed research released in March that found the Moderna and Pfizer-BioNTech vaccines were 90 percent effective at preventing all infections.