A second study was coordinated with the CDC and found that people vaccinated with either Pfizer’s or Moderna’s vaccines are much less likely to end up in the hospital on a ventilator or to die from infection than unvaccinated people.

Unvaccinated patients accounted for 91% of Covid-19 deaths and nearly 94% of those with a combined need for ventilators or death, the team reported in the Journal of the American Medical Association.

“We are very confident now that the vaccine is still helping you, even if you get Covid,” Dr. Wesley Self, an associate professor at Vanderbilt University who led the study team, told CNN. “Even those who get sick don’t get as sick as they would if they were unvaccinated.”

The team at 21 US hospitals in 18 states studied 4,513 patients admitted to hospitals with respiratory diseases between March and July. “Unvaccinated patients accounted for 84.2% of COVID-19 hospitalizations. Hospitalization for COVID-19 was significantly associated with decreased likelihood of vaccination,” the team wrote.