If You've Had COVID, This Is How Long You Have Immunity, New Study Finds
Antibodies from the virus can stick around in your system for a while after recovery.
There's not much of a bright side to contracting COVID, but people have at least clung to the hope that they'd acquire some immunity after recovering from the virus. Studies have shown that people who had COVID have maintained some level of antibody response after the infection leaves their system, though it's still not clear exactly how long those antibodies last—and how thoroughly they protect you from getting sick again. Now, a new study suggests that you may be in the clear for longer than we previously thought. According to recent research, the overwhelming majority of people who have COVID retain antibodies against the virus for at least 10 months.
The study from Labcorp, which was published on May 24 in the medical journal The Lancet, examined samples from more than 39,000 people who were previously infected with COVID. The researchers found that nearly 87 percent of them had antibodies at least 10 months after their infection. The researchers also found that people over 65 generally didn't hang on to antibodies as long as those under 65.
Another study published on May 24 in the journal Nature also found promising results that suggest antibodies linger for months. The study found that mild cases of COVID result in lasting antibody protection and that reinfections are likely uncommon. While the study found antibody-producing cells in people 11 months after they experienced their first symptoms, researchers believe immunity lasts even longer than that, as it has with similar coronaviruses. In the 2002 SARS outbreak, for example, those who came down with the virus were naturally immune for about two years on average.
While this is exciting news, more research needs to be conducted and more time needs to pass before scientists can definitively determine how long and how well COVID survivors are protected from reinfection, Brian Caveney, MD, Labcorp Diagnostics chief medical officer and president, told USA Today. However, he noted that the findings of the Labcorp study are still a win. "The prolonged presence of certain antibodies is a promising sign as we continue thinking about safely emerging from the pandemic, as well as future vaccinations and the timing of booster shots," said Caveney.
Additional research also has to be done to understand whether these antibodies would be effective against newer variants of the virus. An expert not involved with the study, Kevin Dick, district health officer for Washoe County, Nevada, pointed out to USA Today, "the study also doesn't address if antibodies from a COVID-19 infection can protect against COVID-19 variants." He noted that this is part of the reason that it's important for people who may have acquired natural immunity to still get vaccinated. Serious COVID outbreaks in Brazil, India, and South Africa seem to be driven, in part, by reinfections due to waning immunity and the newer variants' ability to evade immunity, Cambridge microbiology professor Ravi Gupta, PhD, said on Twitter.
Although antibodies can be useful in protecting you against various illnesses, they're not the only component that's key to preventing reinfection, either. According to Healthline, helper T cells, killer T cells, and B cells are all also necessary to acquire immunity. Helper T cells help recognize pathogens, killer T cells then kill those pathogens, and B cells make new antibodies when your body needs them, explain the experts at Healthline.
In terms of COVID, there haven't been enough studies yet to see how natural immunity holds up. Lauren Rodda, PhD, a senior postdoctoral fellow in immunology at the University of Washington School of Medicine, told Healthline that gaining a deeper understanding of naturally acquired immunity "would require tracking the re-exposure of a significant number of people and determining if they get sick."
That's why those who've come down with COVID are urged to get vaccinated, with the Centers for Disease Control and Prevention (CDC) saying that "experts do not yet know how long you are protected from getting sick again after recovering from COVID-19. Even if you have already recovered from COVID-19, it is possible—although rare—that you could be infected with the virus that causes COVID-19 again."
White House COVID adviser Anthony Fauci, MD, said at a press briefing earlier this month that vaccine-induced immunity is actually stronger, even if less long-lasting, when compared to natural immunity. "Vaccines, actually, at least with regard to SARS-CoV-2 can do better than nature," he explained. "Vaccination in people previously infected significantly boosts the immune response." He also cited a May study out of the University of California, Irvine, which has not yet been peer reviewed, that found that people who'd received two doses of an mRNA vaccine—either from Pfizer or Moderna—had "antibody titers up to 10 times more than when you recover from a natural infection."
He specifically noted that those who'd been vaccinated had "increased protection against the variants of concern" as opposed to those who relied on natural immunity. "Vaccines are highly efficacious," he concluded. "They are better than the traditional response you get from natural infection."