Hong Kong has first case of reinfection

The first case of someone being reinfected with coronavirus has been reported by researchers in Hong Kong.

The findings could have significant implications for the development of vaccines and what is known about natural immunity against Covid-19.

Researchers at the University of Hong Kong’s (HKU) department of microbiology said that an “apparently young and healthy patient had a second episode of Covid-19 infection which was diagnosed 4½ months after the first episode”.

They added that the case illustrates reinfection can occur a few months after recovery from the first infection.

The man had no symptoms – was asymptomatic – during the second infection which was picked up by screening tests on returning passengers at Hong Kong airport.

Genetic sequencing of the virus showed he was infected twice by different strains of Covid-19, the researchers said.

They added that the findings suggest SARS-COV-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.

Therefore, people with previous Covid-19 infection should comply with control measures like wearing face coverings and social distancing.

One of the researchers, Dr Kelvin Kai-wang To, clinical associate professor, Department of Microbiology, Li Ka Shing Faculty of Medicine, HKU, said: “This case shows that patients recovered from Covid-19 can get reinfected.”