A study in the United States that compared the protection between having had COVID-19 and being vaccinated concluded that getting vaccinated is the safest way to prevent the disease again.
The study reviewed infections in New York and California last summer and fall and found that people who were vaccinated and had recovered from a COVID-19 infection had the greatest protection.
But the people who were not vaccinated and got the infection were close by. By the fall, when the delta variant became dominant and booster doses were not yet widely offered, those people had lower diagnoses than vaccinated people who had not previously been sick with COVID-19.
The US Centers for Disease Control and Prevention (CDC), which published the study on Wednesday, highlighted several caveats to the research. And some outside experts were wary of the conclusions and wary of how they might be interpreted.
“The message is that some immunity is generated from a symptomatic COVID infection,” said immunologist E. John Wherry of the University of Pennsylvania. “But it’s still much safer to get immunity from the vaccine than from an infection.”
People have long been urged to get vaccinated even if they have contracted COVID-19 because both types of protection eventually wear off, and there are too many unknowns to rely on just a past infection, especially one that happened a long time ago time, added immunologist Ali Ellebedy of Washington University in St. Louis.
“There are so many variables that you can’t control it and you can’t use it as a way of saying ‘Oh, I’m infected so I’m protected,'” Ellebedy said.
The research aligns with a small set of studies that found unvaccinated people who previously had coronavirus had a lower risk of getting it again or getting sick compared to people who hadn’t been infected.
However, the study authors concluded that vaccination “remains the safest strategy” to prevent infection and that “all eligible individuals should be up-to-date with their COVID-19 vaccination.”