US Coronavirus cases
US Coronavirus casesReuters

While the world is battling the deadly coronavirus, there was a sign of hope looking at the recovered patients. But that seems to have changed now as first confirmed case of COVID reinfection has been reported in Hong Kong.

A 33-year-old was infected with COVID-19 after recovering from the virus in April. Researchers are using this case as evidence that re-infection might reappear within a few months. The infection was diagnosed during an airport screening when the man was returning from Europe to Hong Kong this month.

World's first case of COVID reemergence

"Our findings suggest that SARS-CoV-2 may persist in humans," Kwok-Yung Yuen and his colleagues said in a paper accepted for publication in the journal Clinical Infectious Diseases on Monday. The scientists have concluded that the infection may continue to circulate "even if patients have acquired immunity via natural infection or via vaccination," they said.

This is the world's first documentation of a patient who recovered from COVID-19 and got infected again later. The patient was found to have contracted a different strain of COVID-19 and remained asymptomatic during its reemergence.

Courtesy: Reuters

"Before this report, many believe that recovered Covid-19 patients have immunity against re-infection, however, there is evidence that some patients have a waning antibody level after few months," the University of Hong Kong researchers said in the statement.

Don't jump to conclusions

While this might put many on the edge even as they recovered from the deadly virus, which has infected millions and killed thousands around the world, World Health Organisation (WHO) epidemiologist Maria Van Kerkhove said there's no need to jump to any conclusions after the Hong Kong case.

There have been cases of COVID-19 reappearing in patients, but the Hong Kong case is first of its kind as it happened after a full recovery. There was a small percentage, about 5-15 percent, of patients in China who tested positive after being discharged.

Wang Guiqiang, an infectious disease specialist in China's expert group for COVID-19 treatment, said there are two possible explanations to the Hong Kong case: the virus still existed in the lungs but wasn't detected in the samples or there were low sensitivity of tests and weak immunity.

Do not panic

It is important not to panic at the news of COVID reinfection. Prof. Akiko Iwasaki, Professor in the Department of Molecular, Cellular, and Developmental Biology at Yale University, explained in a series of tweets why this isn't such bad news after all.

"This is no cause for alarm - this is a textbook example of how immunity should work."

COVID reinfection
COVID reinfection
COVID reinfection

"Lastly, while this is a good example of how primary infection can prevent disease from subsequent infection, more studies are needed to understand the range of outcomes from reinfection," she concluded.