The data suggest that anyone who has had the virus should still 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.
Although it is unlikely that most people will get the disease again for at least six months, the elderly are more prone to reinfection, according to the results published on Wednesday in the Lancet. The study of test results in Denmark last year showed that those under the age of 65 who had Covid were about 80% protected against cancer again. Protection dropped to 47% for those over 65.
The data suggest that those who have had the virus should still be vaccinated, the authors said. Natural protection cannot be trusted, especially for the elderly, who are increased risk of serious illness. Denmark’s analysis focused on the original coronavirus strain and made no assessment of new variants considered to be more transmissible.
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“Our findings make it clear how important it is to implement policies to protect the elderly during the pandemic,” even though they already had Covid-19, said Steen Ethelberg, senior researcher at the Statens Serum Institut in Copenhagen, in a statement. “Our insights can also inform policies focused on broader vaccination strategies and on easing blocking restrictions.”
The study authors analyzed the data collected as part of Denmark’s national SARS-CoV-2 test strategy. More than two-thirds of the population, or about 4 million people, were tested over a period spanning the first and second waves. The analysis found that only 0.65% of people returned a positive CRP test during both waves. A larger proportion – 3.3% – had a positive result after the previous negative.
In line with the results of other studies, there was no evidence that protection against reinfection has declined 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 not yet been determined. It was also not possible to assess whether the severity of the symptoms affected the patient’s degree of immunity, they wrote.
“All of this data is confirmation, if necessary, that for SARS-CoV-2 the have hope protective immunity through natural infections may not be available to us and a The global vaccination program with highly effective vaccines is the lasting solution ”, wrote Professors Rosemary Boyton and Daniel Altmann, from Imperial College London, in a comment linked to the study.