Researchers at the University of Hong Kong (HKU) said that they had confirmed the world's "first case" of coronavirus reinfection after a 33-year-old man got the infection once again after over four months. The man's two viral signatures were "completely different", and belonged to different coronavirus lineages, according to researchers after he suffered a relapse. The researchers found that first strain resembled those that were collected in March and April, however, the second strain matched the virus found in Europe after the person visited the continent in July and August.
The man had travelled to Spain and had returned to Hong Kong via London after he was detected with the virus during screening at the airport. The man's PCR swab test was positive."Our study proves that immunity for COVID infection is not lifelong, in fact, reinfection can occur quite quickly," Kelvin Kai-Wang To, microbiologist and lead author of the study, said.Although there have been cases reported of reinfections, however, this is the first time it has been proven after tests. “This is the world’s first documentation of a patient who recovered from COVID-19 but got another episode of COVID-19 afterwards,” the researchers said in a statement.Worldwide, some 24 million people are known to have been infected with Covid-19 which first emerged in China's Wuhan last December.