Scientists discover the first man to get COVID-19 twice—with different strains of the virus

covid-19 reinfection coronavirus hong kong
Photo via NIH Image Gallery/Flickr (Public Domain)
  • For apparently the first time, a person has been reinfected by COVID-19
  • The virus appears to act more like the seasonal flu than SARS or MERS
  • This has implications for immunity, as well as potential vaccines

A man in Hong Kong has been diagnosed with a second bout of COVID-19, four months after recovering from his first. Experts are concerned by the case, which appears to show that immunity to the coronavirus may be short-lived.

The 33-year-old man experienced mild symptoms during his first bout of coronavirus. He has not experienced any symptoms from his second infection. The reinfection may not have been noticed, but the man recently returned from a trip to Spain and was tested upon arrival in Hong Kong. Researchers noted that the second infection was “caused by a new virus that he acquired recently rather than prolonged viral shedding.”

Viral shedding can occur for weeks after the virus has been kicked, and that can lead to false positives in COVID-19 tests. In this case, however, researchers found significant differences between the man’s first bout of illness and his COVID-19 reinfection. This eliminates the possibility that prolonged viral shedding is to blame. 

The man’s lack of symptoms is giving researchers hope that cases of coronavirus reinfection will be milder. Initially, hopes were high that COVID-19 would act like SARS and MERS, which had immunities that tended to last several years. Instead, the coronavirus appears to act more like the seasonal flu. 

The reinfection also has implications for any coronavirus vaccines currently in development. As noted by the University of Exeter’s Dr. David Strain, “Vaccinations work by simulating infection to the body, thereby allowing the body to develop antibodies. If antibodies don’t provide lasting protection, we will need to revert to a strategy of viral near-elimination in order to return to a more normal life.”

Sources: New York Times, Independent, Japan Times

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