Those who recover from COVID-19 may experience more dangerous symptoms when re-infected.
According to The Lancet Infectious Diseases, scientists from the University of Nevada and other scientific organizations in the United States confirm this.
The researchers reported a 25-year-old man infected with two different variants of SARS-CoV-2 over a 48-day period. It turned out that the second infection was more serious than the first: the patient was hospitalized with oxygen support.
Experts also noted four other cases of re-infection in Belgium, the Netherlands, Hong Kong and Ecuador.
Experts believe that this was the second time that a patient from Nevada was exposed to a high dose of the virus, which caused a more severe reaction. According to other hypotheses, the man suffered from a more virulent strain of SARS-CoV-2.
Recurrent infections pose a threat to COVID-19 vaccine development measures.
However, it is also emphasized that such cases are still rare in the world.