HONG KONG—A team of researchers have documented a case of Covid-19 reinfection, offering evidence that patients who have recovered from the viral disease could be infected a second time, months after the initial episode.
In a paper accepted on Monday by the Clinical Infectious Diseases journal, scientists from the University of Hong Kong reported the case of a 33-year-old man who had an asymptomatic Covid-19 episode 4½ months after a symptomatic infection.
The findings, based on a single patient, would if replicated bolster the theory that immunity to SARS-CoV-2, the virus that causes Covid-19, could last only a few months, similar to coronaviruses that cause the common cold.
That would have implications for recommended precautions for recovered patients and for cycles of vaccinations once they become available. The case report also highlights the importance of widespread rapid testing and isolation of cases, experts said.
The paper didn’t specify whether the patient was infectious the second time around, but infectious-disease researchers and virologists have said for months that social distancing, good personal hygiene and masking would continue to be important for stemming the spread of the virus until more is known about how long immunity lasts, whether from natural infection or vaccination.