COVID-19 vaccines may provide protection for at least a year, and possibly even a lifetime, to people who were previously exposed to the virus, two new studies suggest.
Both studies looked at people who had been exposed to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) about a year earlier, The New York Times reported. Cells that remember the virus persist in the bone marrow and may produce antibodies whenever needed, according to a study published in the journal Nature. The other study, posted online at the biology research site BioRxiv, showed that these memory B cells continue maturing and strengthening for at least 12 months after initial infection with the coronavirus.
Together, the findings suggest that most people who have recovered from SARS-CoV-2 infection and were later vaccinated will not require booster shots, The Times said. But it is likely that vaccinated people who were never infected will still need booster shots, as will some people who were infected but did not produce a strong immune response against the virus.
“The papers are consistent with the growing body of literature that suggests that immunity elicited by infection and vaccination for SARS-CoV-2 appears to be long-lived,” Scott Hensley, Ph.D., an immunologist at the University of Pennsylvania who was not involved in the research, told The Times.
The memory B cells that are produced in response to coronavirus infection and boosted by vaccines are so powerful that they can fight off even variants of the virus, eliminating the need for boosters, according to Michel Nussenzweig, M.D., Ph.D., an immunologist at Rockefeller University in New York City, who led one of the studies. “People who were infected and get vaccinated really have a terrific response, a terrific set of antibodies, because they continue to evolve their antibodies,” Nussenzweig told The Times. “I expect that they will last for a long time.”