The data suggest that those who had the virus should continue to be vaccinated.
Photographer: Nathan Laine / Bloomberg
Photographer: Nathan Laine / Bloomberg
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Older people are more at risk of catching Covid-19 again after recovering from a previous virus attack, new research shows.
While most people are unlikely to get sick again for at least six months, the elderly are more prone to reinfection, according to results published Wednesday in the Lancet. A study of test results in Denmark last year showed that people under the age of 65 who had Covid were about 80% protected from taking them again. Protection has dropped to 47% for those over 65 years of age.
The data suggest that those who had the virus should still be vaccinated, the authors said. Natural protection cannot be invoked, especially for the elderly most at risk of severe disease. The Danish analysis focused on the original coronavirus strain and did not make any assessment of the new variants considered to be more transmissible.
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“Our findings clearly show how important it is to implement policies to protect the elderly during the pandemic,” even though they already had Covid-19, said Steen Ethelberg, a senior researcher at the Statens Serum Institut in Copenhagen, in a statement. “Our perspectives could also inform policies focused on broader vaccination strategies and the reduction of blocking restrictions.”
The study authors analyzed the data collected as part of the national SARS-CoV-2 testing strategy in Denmark. More than two-thirds of the population, or about 4 million people, were tested in a period comprising the first and second countries. waves. The analysis found that only 0.65% of people returned a positive PCR test during both waves. A higher proportion – 3.3% – obtained a positive result after a previous negative one.
According to the results of other studies, there was no evidence that protection against reinfection had decreased within six months, the authors said. However, as the virus was only identified in December 2019, the full period of protective immunity conferred by the infection has yet to be determined. It was also not possible to assess whether the severity of the symptoms affected a patient’s immunity, they wrote.
“These data are all confirmations, if necessary, for SARS-CoV-2 the hope of protective immunity through natural infections may not be available to us and a the global vaccination program with high-efficiency vaccines is the sustainable solution, ”wrote professors Rosemary Boyton and Daniel Altmann of Imperial College London in a commentary on the study.