Levels of an antibody found in recovered COVID-19 patients fell sharply in 2-3 months after infection for both symptomatic and asymptomatic patients, according to a Chinese study published in Nature Medicine.
These findings raises questions about the length of any immunity against the novel coronavirus.
The research, published in Nature Medicine on June 18, highlights the risks of using COVID-19 ‘immunity passports’ and supports the prolonged use of public health interventions such as social distancing and isolating high-risk groups, researchers said.
The research, which studied 37 symptomatic patients and 37 asymptomatic patients, found that of those who tested positive for the presence of the IgG antibody, one of the main types of antibodies induced after infection, over 90% showed sharp declines in 2-3 months.
Jin Dong-Yan, a virology professor at the University of Hong Kong who was not part of the research group, said the study does not negate the possibility that other parts of the immune system could offer protection.
