The study, published in mBio, is the first to show that the COVID-19-causing virus, SARS-CoV-2, induces memory B cells, long-lived immune cells that detect pathogens, create antibodies to destroy them and remember them for the future. The next time that pathogen tries to enter the body, those memory B cells can hop into action.
Because memory B cells can survive for decades, they could protect COVID-19 survivors from subsequent infections for a long time, but further research will have to bear that out.
The study is also the first to report cross-reactivity of memory B cells — meaning B cells that once attacked cold-causing coronaviruses appeared to also recognize SARS-CoV-2. Study authors believe this could mean that anyone who has been infected by a common coronavirus — which is nearly everyone — may have some degree of pre-existing immunity to COVID-19.
“When we looked at blood samples from people who were recovering from COVID-19, it looked like many of them had a pre-existing pool of memory B cells that could recognize SARS-CoV-2 and rapidly produce antibodies that could attack it,” said lead study author Mark Sangster.
