There’s encouraging news about antibodies in a new paper published in the journal Science from researchers at New York City’s Mount Sinai Hospital. In their study of the antibody responses of patients with either mild or moderate Covid-19, antibody levels appeared to stay relatively stable for at least five months, and their presence was correlated with the inactivation of the virus.
Antibodies are molecules pumped out by the immune system in response to infection, and they have a role in preventing future infections, though exactly how they function within the context of Covid-19 isn’t clear yet. Scientists are urgently trying to figure out whether the presence of antibodies actually means a person is protected from future infection as well as how long antibodies last in the body. Knowing this is crucial, especially for vaccine development.
Since March 2020, Mount Sinai has been screening people with either suspected or confirmed Covid-19 for antibodies in hopes of using their plasma to treat people with severe Covid-19. Out of roughly 72,000 people screened, over 30,000 tested positive for antibodies to Covid-19. Specifically, these antibodies targeted the virus’s much-discussed “spike protein” — a feature of coronaviruses that’s crucial for infection. To determine what role these so-called anti-spike antibodies have in the overall effort to prevent coronavirus infection, the researchers ran more assays using actual SARS-CoV-2 samples, confirming that having certain levels of these antibodies is correlated with virus neutralization. They caution, though, that it’s not yet known whether having these levels of antibodies in the blood protects a person from Covid-19 infection.
Then, to find out how long these antibodies might last in the body, the researchers monitored the antibodies of 121 plasma donors over three different time points. They found that antibody levels were stable for at least the five months during which they conducted the study.
This is welcome news, especially in light of recent research from the U.K. suggesting that antibody levels drop over time. As I wrote in the Coronavirus Blog yesterday…