Researchers in Hong Kong Monday claimed to have proved that a man was infected by COVID-19 for a second time after having recovered from the illness.
It is the first such case documented by a team of researchers at the University of Hong Kong. The man, 33, an IT worker, recovered from coronavirus and later was released from hospital in April, according to rthk.com. However, he again tested positive for the virus when he returned from Spain early in August.
According to the university research team, the “genetic sequencing showed the virus strains contracted by him in April and August were clearly different.”
“Many believe that recovered COVID-19 patients have immunity against re-infection because most developed a serum neutralizing antibody response. However, there is evidence that some patients have waning antibody level after a few months," the researchers said.
“Our findings suggest that the SARS-CoV-2 [severe acute respiratory syndrome coronavirus 2] may persist in the global human population as is the case for other common cold-associated human coronaviruses, even if patients have acquired immunity via natural infection,” they added.
The researchers said the patients who recovered after getting coronavirus should also wear masks and maintain social distancing.
“Since the immunity can be short-lasting after natural infection, vaccination should also be considered for those with one episode of infection,” the HKU team said.
Meanwhile, Hong Kong Monday reported its lowest coronavirus cases since July 3 with only nine new infections. The semi-autonomous region under China has reported 4,691 infections and 77 deaths due to COVID-19.
Since originating in China last December, COVID-19 has claimed over 809,000 lives in 188 countries and regions. More than 23.44 million cases have been reported worldwide, while over 15.2 million patients have recovered, according to figures compiled by the US’ Johns Hopkins University.