(WNCN) — If you’ve been infected with a mild case of COVID-19, new studies suggest your body may make antibodies against the virus for most of your life.
Researchers at Washington University in St. Louis, Missouri say they have identified long-lived antibody-producing cells in the bone marrow of people who have recovered from COVID-19.
According to researchers, there is evidence that immunity triggered by COVID-19 infection will be “extraordinarily long-lasting”.
Antibodies are proteins that can recognize and help to inactivate viral particles and are a key immune defense. After a new infection, short-lived cells called plasmablasts are an early source of antibodies. But these cells recede soon after a virus is cleared from the body, and other, longer-lasting cells make antibodies: memory B cells patrol the blood for reinfection, while bone marrow plasma cells (BMPCs) hide away within bones, trickling out antibodies for decades.Study findings published in the journal Nature
“A plasma cell is our life history, in terms of the pathogens we’ve been exposed to,” said Ali Ellebedy, a B-cell immunologist at Washington University, who led the study, published in Nature on May 24.
Researchers tracked antibody production in 77 people who recovered from mostly mild cases of COVID-19 and found that COVID-19 antibodies plummeted four months after infection.
The reduction of antibodies slowed, researchers said, and up to 11 months after infection, antibodies that recognized the SARS-CoV-2 spike protein could still be detected.
None of the 11 people who had never had COVID-19 had such antibody-producing cells in their bone marrow, the study found.
“Last fall, there were reports that antibodies wane quickly after infection with the virus that causes COVID-19, and mainstream media interpreted that to mean that immunity was not long-lived,” said Ellebedy. “But that’s a misinterpretation of the data. It’s normal for antibody levels to go down after acute infection, but they don’t go down to zero; they plateau. Here, we found antibody-producing cells in people 11 months after first symptoms. These cells will live and produce antibodies for the rest of people’s lives. That’s strong evidence for long-lasting immunity.”
Researchers said they are now studying whether vaccination also induces long-lived antibody-producing cells.
Read the findings from the study here.