A man in Hong Kong has become the first confirmed patient to be infected with the coronavirus a second time, according to researchers at the University of Hong Kong.
The new finding suggests that some patients who recover from COVID-19, the disease caused by the coronavirus, may have only short-lived immunity from reinfection. The case will likely also be significant for scientists who have been working on treatments using antibodies from recovered coronavirus patients, and those who have been scrambling to develop a safe and effective vaccine.
The 33-year-old man in Hong Kong developed mild symptoms in late March, when he was first diagnosed with COVID-19, the researchers at the University of Hong Kong wrote in a study that has been accepted for publication by the medical journal Clinical Infectious Diseases. The patient was hospitalized on March 29, but his symptoms subsided and he was discharged on April 14, according to the study.
The second infection occurred more than four months later, reportedly after the man returned to Hong Kong from Spain, via the United Kingdom. The patient tested positive on Aug. 15 and was hospitalized but remains asymptomatic, according to the study.
Early research on coronavirus antibodies had found that their levels waned after a few months, which could suggest that any potential immunity to the virus may not last long.
Dr. Anthony Fauci, who heads the National Institute of Allergy and Infectious Diseases in the U.S. and is the nation’s top infectious disease expert, has previously said that immunity to other known coronaviruses, including those that cause the common cold, typically lasts only three to six months.
“It may be completely different with this coronavirus,” he said in an interview with the medical journal JAMA. “It may be that people induce a response that’s quite durable. But if it acts like common coronaviruses, it likely is not going to be a very long duration of immunity.
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