In rare cases of COVID-19 after vaccination, patients are sick for less time

In the rare cases of COVID-19 that occur after vaccination, patients are likely to be sick for less time and have milder symptoms than if they were unvaccinated, according to a U.S. study of nearly 4,000 healthcare personnel, first responders, and other frontline workers.

In participants who were tested weekly since mid-December, COVID-19 has been diagnosed in five who were fully vaccinated with an mRNA vaccine from either Pfizer and BioNTech or Moderna, 11 who were partially protected, having received either one shot or were less than 14 days out from their second, and 156 who were unvaccinated.

Most unvaccinated patients were sick for at least two weeks, compared with only one week for vaccinated patients, the researchers reported on Wednesday in The New England Journal of Medicine.

Patients who were fully or partially vaccinated had 58% lower odds of fever and spent an average of 2.3 fewer days in bed than unvaccinated patients. Their viral loads also averaged 40% lower.

“If you get vaccinated, about 90% of the time you’re not going to get COVID-19,” coauthor Dr. Jeff Burgess of the University of Arizona said in a statement. “Even if you do get it, there will be less of the virus in you and your illness is likely to be much milder.”