Antibody levels may start to decrease two to three months after a COVID-19 infection, especially in asymptomatic patients, a study published in Nature Medicine found.
For the study, researchers examined antibody response in 37 Chinese patients who were hospitalized for COVID-19 but did not have symptoms. Researchers compared their antibody response to that of 37 symptomatic patients.
Within eight weeks of hospitalization, 81 percent of asymptomatic patients had decreased antibody levels, compared to just 62 percent of symptomatic patients. Within this time period, antibody levels fell to undetectable levels in 40 percent of asymptomatic patients and 12.9 percent of symptomatic patients.
The findings suggest asymptomatic patients may have a weaker immune response to the virus, researchers said.
While the study is limited by its small sample size, it could complicate the idea of giving "immunity certificates" to people who've recovered from COVID-19, reports The New York Times.
To view the full study, click here.