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Published on: 13/10/2020 09:44
He contracted Covid twice within a few months, and the second time with more severe symptoms. It happened to a 25-year-old from Nevada, United States, with no known health problems or immune deficiencies that made him particularly vulnerable to the virus. Now the patient is better, but the study on ‘Lancet Infectious Diseases’, taken up by the BBC, raises new questions about the immunity of the infected, even if cases of reinfections remain rare.
The first symptoms – including sore throat, cough, headache, nausea and diarrhea, appeared on 25 March – and the first positive swab dates back to 18 April. From April 27 the patient had no more symptoms and on May 9 and then 26 he tested negative, but on May 28 the symptoms returned. So on June 5 the young man tested positive for the second time but with hypoxia (low level of oxygen in the blood) and shortness of breath, to the point of having to be hospitalized.
According to doctors, the 25-year-old contracted the coronavirus twice, rather than the original infection, it went dormant and then came back. To support him the comparison of the genetic codes of the virus from samples taken while the patient was symptomatic: the sequences were too different to be caused by the same infection.
“Our results signal that a first infection may not necessarily protect against future infections,” said Dr. Mark Pandori of the University of Nevada. “The possibility of reinfection could have significant implications for our understanding of Covid-19 immunity,” he added, suggesting people who have recovered to continue following guidelines relating to social distancing, masks and hand washing.
Scientists around the world are still grappling with the thorny issue of coronavirus and immunity. Does everyone become immune? Even people with very mild symptoms? How long does the protection last? These are very important questions to understand how the virus will affect us in the long term and could have implications on vaccine research but also on strategies such as, for example, contested herd immunity.
So far, however, reinfection appears to be rare: there have been only a few examples of people who have fallen ill multiple times, out of over 37 million confirmed cases. Reports from Hong Kong, Belgium and the Netherlands indicate that the new infections were less severe than the first. While a patient in Ecuador mirrored the US case as being more serious but didn’t need hospital treatment, remembers the BBC online.
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