Immunity to SARS-CoV-2 Lasts at Least Six Months, Data Show
Half a year after infection, people who had recovered from COVID-19 had robust antibodies, along with traces of the virus in their gut, which may drive long-lasting immunity.
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Curious if the B cells produced the same antibodies a month after infection as six months after infection, Gaebler and colleagues compared the memory B cell receptors’ genetic sequences and found significant shifts over time. This observation, combined with the improved potency of antibodies produced by these B cells, indicates the B cells and antibodies evolved in response to infection.
Gaebler says he was surprised to see the antibodies had evolved. That typically happens when a pathogen hides out somewhere in the body or specifically in cells’ DNA even after symptoms of infections cease—for instance, with HIV. Saurabh Mehandru, a gastroenterologist at Mount Sinai Hospital, and colleagues had been looking for the SARS-CoV-2 virus in recovered COVID-19 patients’ intestines and had identified traces of it in the gut. His group and Gaebler’s decided to team up to see if those viral stowaways in the gut could be spurring memory B cells’ evolution.
Mehandru’s team took a close look at biopsies from 14 recovered patients infected roughly four months earlier, on average. At the time of the tissue collection, none of them had a positive PCR result for the virus, yet SARS-CoV-2 RNA was detected in the small intestine of three of the 14 patients, and biopsies from five of the patients contained SARS-CoV-2 N protein. Electron tomography on one patient’s biopsy also revealed SARS-CoV-2 viral particles.
“If you have the virus persisting in the intestines, it has the potential to continue to inform the immune system,” Mehandru, a coauthor of the study, tells The Scientist.
https://www.the-scientist.com/news-opinion/immunity-to-sars-cov-2-lasts-at-least-six-months-data-show-68179
