Public health officials have looked to random antibody testing to gauge what percentage of various populations have been infected with coronavirus. We still don't know whether detectable antibodies are necessary for protection from reinfection, however. The CDC currently says that antibody testing is probably not useful 90 days after someone thinks they may have been infected. However, the new study published by the agency suggests that antibody testing may serve little purpose even earlier. By the time of their 60-day follow appointments, antibody levels had declined in almost everyone who had developed them (93 percent).

Source: Daily Mail November 25, 2020 18:59 UTC