Natural Immunity To COVID-19 May Last More Than A Year After Infection, New Studies Show

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Dylan Housman Deputy News Editor
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Two new studies suggest that natural immunity in individuals who have recovered from COVID-19 may be even stronger than previously believed.

A paper published in Nature on Monday by researchers from the Washington University School of Medicine in St. Louis found that cells in the bone marrow of people who had COVID-19 about one year earlier maintained a memory of the virus, allowing them to generate antibodies in case of reinfection. Another new paper, still under peer-review for publishing in Nature, found that these memory cells continue to mature and strengthen for as many as 12 months post-infection.

The evolution of those memory cells means they can tackle more and more variants of the virus over time. (RELATED: Where’s The CDC Guidance For People Who Recovered From COVID-19?)

Previous research has shown that recovery from COVID-19 grants a fairly strong level of natural immunity, particularly in younger people, but it remained unclear exactly how strong that immunity is and how long it lasts. Other SARS viruses tend to see natural immunity wane within a few months post-infection, according to the Washington University researchers.

Despite the immunity lasting longer, it can still be weakened against variants of the virus. “The reason we get infected with common coronaviruses repetitively throughout life might have much more to do with variation of these viruses rather than immunity,” Dr. Scott Hensley of the University of Pennsylvania told The New York Times.

The Washington University study found that not every single participant retained the memory cells 12 months after infection, suggesting that vaccination could still be required for some recovered COVID-19 patients who don’t have as strong an immune response to the virus. (RELATED: Pfizer CEO Says Third Dose Of COVID-19 Vaccine ‘Likely’ Needed Within A Year)

With a potential booster shots on the horizon, the results of this research could indicate that some individuals won’t need them. If someone has natural immunity and also gets vaccinated, they “really have a terrific response, a terrific set of antibodies, because they continue to evolve their antibodies,” Dr. Michel Nussenzweig told The Times. “I expect that they will last for a long time.”