A 33-year-old man from Hong Kong has tested positive for the novel coronavirus (SARS-COV-2) twice this year, making it the first case of COVID-19 reinfection in the world.
On Monday, the University of Hong Kong accepted a pre-print study for publication in the journal Clinical Infectious Diseases, which found that the man’s second positive test for COVID-19 came four-and-a-half months (142 days) after the first.
As reported by AP News and Reuters, the man showed symptoms including a cough, sore throat, fever and headache for three days in his first episode, after testing positive on March 26. However, the study says that when he tested positive the second time he had no symptoms after returning from his travels to Spain via the United Kingdom and being screened at the airport.
“The patient got re-infected 4.5 months after the first infection. Therefore, it shows that for this patient, the immunity induced by the first infection is short lasting,” Dr. Kelvin Kai-Wang To of the University of Hong Kong told CNN.
The University of Hong Kong study, which genetically analysed specimens from the patient for 10 days, confirms that COVID-19 is similar to other seasonal viruses, dispelling the myth of herd immunity, while also potentially setting vaccine developers back with the revelation that any potential vaccine will only be viable for a short window before the virus mutates.
“This case illustrates that re-infection can occur even just after a few months of recovery from the first infection. Our findings suggest that SARS-CoV-2 may persist in humans, as is the case for other common-cold associated human coronaviruses, even if patients have acquired immunity via natural infection or via vaccination,” the report states.
The paper also concluded that patients that have already contracted COVID-19 will need to continue practicing social distancing and should still be vaccinated once a vaccine becomes available to avoid reinfection.