There may be no immunity against COVID-19 - in some cases, antibodies disappear after the patient's recovery, the South China Morning Post reported referring to new research on antibodies by Chinese and American scientists.
Doctors had direct contact with infected patients in the early stages of an outbreak.
As it turned out, at least a quarter of the 23,000 health workers could become infected with coronavirus, but only 4% found to have antibodies.
“People are unlikely to produce long-lasting protective antibodies against this virus,” the researchers concluded.
Besides, over 10 per cent of the examined people may have lost antibody protection within a month or so.