A new study published Monday finds the mRNA COVID-19 vaccines authorized by the U.S. Food and Drug Administration (FDA) reduce the risk of infection by 91 percent for fully vaccinated people.
The two FDA-approved mRNA COVID-19 vaccines are Pfizer-BioNTech vaccine and Moderna vaccine.
This study is among the first to show that mRNA vaccination benefits people who got COVID-19 despite being fully vaccinated or partially vaccinated, according to the study of the U.S. Centers for Disease Control and Prevention (CDC).
Fully vaccinated means 14 or more days after dose 2, and partially vaccinated refers to 14 or more days after dose 1 to 13 days after dose 2.
The findings came from four weeks of additional data collected in CDC's HEROES-RECOVER study of health care workers, first responders, frontline workers, and other essential workers. These groups are more likely to be exposed to the virus that causes COVID-19 because of their occupations.
"Findings from the extended timeframe of this study add to accumulating evidence that mRNA COVID-19 vaccines are effective and should prevent most infections - but that fully vaccinated people who still get COVID-19 are likely to have milder, shorter illness and appear to be less likely to spread the virus to others," said CDC Director Rochelle Walensky.
These benefits are another important reason to get vaccinated, she said.
Other study findings suggest that fully or partially vaccinated people who got COVID-19 might be less likely to spread the virus to others, according to the CDC.
