There are so many questions about what happens after you recover from the coronavirus and how long those antibodies last for. Do you get more antibodies if you get sicker?
A U.K. study published on July 11, which has not yet been peer-reviewed, found that antibodies may start to decline 20 to 30 days after the onset of COVID-19 symptoms and that detectable amounts of antibodies fell rapidly in the weeks afterward.
A Chinese study published in June found that antibody levels in patients who had recovered from COVID-19 fell sharply within two to three months after infection.
“We’re seeing in other countries evidence that people may be losing their antibodies over a period of time,” says Yahoo News Medical Contributor Dr. Dara Kass.
“And so we need to continue to test and track patients not just when they’re actively infected but also as they recover to understand more about what it means to be recovered from this coronavirus.”
An antibody is a protective protein produced by the immune system, binding to foreign substances, like viruses, so they can be neutralized and removed from the body. Antibody testing, which can detect if a person was previously infected, has slowly been ramping up in the United States in tandem with nasal swab testing, which detects active infections. Yet the limitations of antibodies have been acknowledged for a while.
The World Health Organization has for months cautioned against the notion that antibodies provide permanent immunity. “Some governments have suggested that the detection of antibodies to the SARS-CoV-2, the virus that causes COVID-19, could serve as the basis for an ‘immunity passport’ or ‘risk-free certificate’ that would enable individuals to travel or to return to work assuming that they are protected against re-infection,” WHO said on its website in a post dated April 24. “There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection.”
And on Monday, WHO addressed concerns raised by recent studies that antibodies developed against the coronavirus may diminish over time.
People infected with COVID-19 do have an immune response, said Dr. Maria Van Kerkhove, an epidemiologist and WHO’s COVID-19 technical lead, in a press conference. “What we don’t know is how strong that protection is and for how long that protection will last,” she added, noting that studies are underway looking to better understand that question.