If you're avoiding a COVID-19 vaccine because you have antibodies from a prior infection, emerging research might just change your mind. Several studies have now shown that at least some people who were infected with SARS-CoV-2 in 2020 and immunized with mRNA vaccines like Pfizer or Moderna this year have "superhuman" or "hybrid immunity," meaning they produce very high levels of antibodies that are able to neutralize SARS-CoV-2 variants, per NPR. In one small study, antibodies from 14 vaccinated people who'd had prior infections were found to neutralize six variants of concern, including delta and beta; several other related viruses; and the first coronavirus, SARS-CoV-1, which was first identified in 2003 and is radically different from SARS-CoV-2, the virus that causes COVID-19.
These "flexible" antibodies could even neutralize a virus specifically designed to be a doozy, with 20 mutations known to prevent antibodies from binding to it, scientists say. Antibodies from vaccinated people without a prior infection or unvaccinated people with a prior infection, meanwhile, were "powerless" against it, reports the Telegraph. "One could reasonably predict that [people with hybrid immunity] will be quite well protected against most—and perhaps all of—the SARS-CoV-2 variants that we are likely to see in the foreseeable future," says study author Paul Bieniasz, a virologist at Rockefeller University. He suspects they would also "have some degree of protection against the SARS-like viruses that have yet to infect humans."
Another study cited by Gulf News found healthy people with past COVID-19 infections who were given a single vaccine dose had six to 100 times the antibodies of people who had one vaccine dose, two doses, or a prior infection. But, obviously, people are not encouraged to risk hospitalization or worse in pursuit of such immunity. Indeed, it's unclear who actually achieves it. Another study found up to a third of people with a prior infection don't produce antibodies, per the Telegraph. On the bright side, research conducted by University of Pennsylvania immunologist John Wherry and colleagues shows "some of this antibody evolution happening in people who are just vaccinated," he tells NPR, adding booster doses could speed the process. (Read more COVID-19 stories.)