MONDAY, Nov. 2, 2020 (HealthDay News) — How long does a person who has had mild-to-moderate COVID-19 retain the antibodies that can help them fight future infections? A new study suggests that resistance lasts at least five months.
In search of potential donors for convalescent plasma therapy, researchers from Mount Sinai Health System in New York City screened more than 72,000 recovered patients between March and October.
Of those, more than 30,000 tested positive for antibodies, and many had notable Immunoglobulin G (IgG) antibody responses. Researchers evaluated the antibodies, then followed up with 121 plasma donors to see how long their immune response had lasted. Their immune responses remained stable after about five months, researchers found.
Convalescent plasma therapy uses blood plasma from recovered coronavirus patients to treat others who are infected.
Though it’s not conclusive yet, researchers said it appears that these antibodies decrease the odds of reinfection and may result in milder disease if it happens.
The new study — led by Dr. Ania Wajnberg and colleagues — contradicts other recent research, including findings published in June that showed antibodies waning eight weeks after infection.
One potential explanation: The studies targeted different viral antigens. This might suggest that the antibody response over time depends on the specific antigen, the researchers said.
Assessing the antibody response in mild and symptom-free cases is especially important, according to the study, because they account for the bulk of COVID infections. Researchers plan to continue evaluating these participants.
Their study was published Oct. 28 online in the journal Science.
“We believe it is imperative to swiftly perform studies to investigate and establish a correlate of protection from infection with SARS-CoV-2,” the researchers said in a journal news release.
More information
The U.S. National Institutes of Health has more about COVID-19 antibody research.
SOURCE: Science, news release, Oct. 28, 2020
