A question on many minds right now: do you have antibodies for the novel coronavirus (COVID-19)? And if you do have antibodies for COVID-19, how long will they last? Will Kimbrough, MD, a primary care provider at One Medical in Washington DC, told POPSUGAR that while "this is a super hot topic at the moment, unfortunately — because the virus that causes COVID-19 is so new — there's no way for us to accurately know the answer yet." That said, researchers are making some progress in this area.
The antibodies in question are two immunoglobulins, IgM and IgG, explained Kelly Snowden, physician's assistant at Perlman Clinic in La Jolla, CA. The presence of these antibodies in your blood may indicate recent or past exposure to SARS-CoV-2, the novel coronavirus. According to Snowden, the type of antibody could indicate how recent the exposure was, and each one stays in the body for a different length of time.
- IgM: The presence of this antibody "indicates current or recent infection with the SARS-CoV-2 virus," she said. "IgM antibodies are usually detected three to five days post-symptom onset in symptomatic patients, and around seven days post-infection in asymptomatic patients. IgM disappears around 21 days."
- IgG: If this antibody is detected, it "indicates past exposure to SARS-CoV-2; IgG antibodies are usually produced 14 to 21 days post-infection and can be detected for months to years later."
That said, "the duration of human immunity to SARS-CoV-2 remains to be determined," Snowden noted. She also emphasized that testing isn't definitive, so whatever your results, you should continue to follow CDC guidelines to protect yourself and others.
John Whyte, MD, MPH, chief medical officer at WebMD, told POPSUGAR that though we don't know for sure, "we do believe that patients with COVID antibodies have some immunity," possibly for months or years, based on data collected from previous viruses. "This is particularly important, if we do not have a vaccine for some time," Dr. Whyte said. "But we don't believe it's like measles where one develops lifelong immunity."
David Erstein, MD, a New York board-certified allergist and immunologist working with Advanced Dermatology PC, agreed. "At this point, we don't quite know how long antibodies to COVID-19 will last, and studies are ongoing," he explained. "However, promisingly, studies of similar viruses like SARS (SARS-CoV) show immunity which peaks at around four months and offers protection for two to three years. Hopefully our body's response to COVID-19 will react similarly."
However, Dr. Kimbrough noted that it's reasonable to think this is true of "significant" infection. "The flag of 'significant' is important here, as for many viruses, the levels of antibodies generated correlate with how serious the infection is," he said. "Many of the asymptomatic or very mild cases we're seeing with COVID may not trigger the same level of antibody response as we saw in SARS studies."
POPSUGAR aims to give you the most accurate and up-to-date information about the coronavirus, but details and recommendations about this pandemic may have changed since publication. For the latest information on COVID-19, please check out resources from the WHO, CDC, and local public health departments.