HONG KONG - A Hong Kong man who recovered from COVID-19 was infected again four-and-a-half months later in the first documented instance of human re-infection, researchers at the University of Hong Kong said on Monday.
The patient had appeared to be previously healthy, researchers said in the paper, which was accepted by the international medical journal Clinical Infectious Diseases. "Immunity induced by vaccination can be different from those induced by natural infection," To said."[We] will need to wait for the results of the vaccine trials to see if how effective vaccines are."
The preliminary number of patients in China who tested positive again once being discharged from hospital was 5%-15%, Wang Guiqiang, an infectious disease specialist in China's expert group for COVID-19 treatment, said during a press briefing in May.