A new study published in The Lancet found immunity acquired from a COVID-19 infection reduced the risk of hospitalization and death from reinfection at levels that are "at least as high, if not higher," than two vaccine doses. Still, experts caution vaccination is the safest path to protection against severe disease.
The study, published Feb. 16, involved a review of 65 studies from 19 countries. It is believed to be the largest meta-analysis looking at infection-acquired immunity to date. Researchers compared the risk of subsequent infection among people who have recovered from COVID-19. Those with hybrid immunity, or immunity from both infection and vaccination, were excluded. Findings showed that protection against severe disease remained high, with an 88 percent reduced risk of hospitalization and death from reinfection for at least 10 months.
"This is really good news in the sense that protection against severe disease and death is really quite sustained at 10 months," Christopher Murray, MD, a senior author of the study and director of the Institute for Health Metrics and Evaluation at the University of Washington in Seattle, told NBC News.
Still, experts warned against aiming to acquire immunity through infection.
"The problem of saying, 'I'm going to get infected to get immunity' is you might be one of those people that end up in the hospital or die," Dr. Murray said.
Other healthcare experts who reviewed the study said the findings suggest people can wait longer than the recommended three months to get a booster after an infection.
"If you are thinking about getting a booster, it's a perfectly reasonable call to look at this and say, 'I'll wait six or eight months before getting my booster,'" Bob Wachter, MD, chairman of the department of medicine at University of California San Francisco, told NBC News. "That's a reasonable conclusion from looking at the study."
Dr. Wachter was not involved in the research.