Many people who have been infected with SARS-CoV-2 will probably make antibodies against the virus for most of their lives. So suggest researchers who have identified long-lived antibody-producing cells in the bone marrow of people who have recovered from COVID-19.
The study provides evidence that immunity triggered by SARS-CoV-2 infection will be extraordinarily long-lasting. Adding to the good news, “the implications are that vaccines will have the same durable effect”, says Menno van Zelm, an immunologist at Monash University in Melbourne, Australia.
Antibodies — proteins that can recognize and help to inactivate viral particles — are a key immune defence. 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 in bones, trickling out antibodies for decades.
“This is a very important observation,” given claims of dwindling SARS-CoV-2 antibodies, says [immmunologist] Rafi Ahmed… What’s not clear is what antibody levels will look like in the long term and whether they offer any protection, Ahmed adds. “We’re early in the game.”
