Redefining COVID-19 is rare, but more common in the elderly, a study found

LONDON (Reuters) – Most people who have received COVID-19 have been protected from getting it again for at least six months, a study published Wednesday showed, but older people are more likely to relapse. explain the younger people.

The study, published in the medical journal Lancet, found that only 0.65% of patients tested positive for COVID-19 a second time after their previous infection in the first and second wave of Denmark. That was much lower than the 3.27% who were positive for the virus using very accurate PCR tests after initially negative.

However, the study found that people over 65 had only 47% protection against recurrent infection, compared to 80% protection for younger people.

“Our study confirms the findings of several others: reinterpretation with COVID-19 is rare in younger, healthier people, but older people are at greater risk of relapse,” said Steen Ethelberg of the Statens Serum Institut of Denmark.

“With older people being more likely to suffer from serious illnesses, and sadly dying, our findings highlight the importance of implementing policies to protect older people during the whole disease. -discharged. ”

The authors of the study found no evidence that protection against recurrence decreased over six months later, but said that further studies were needed to assess protection against recurrence from mutations of the coronavirus.

The data analyzed were collected through Denmark’s national verification strategy, where 69% of the population, or 4 million people, were tested over 2020.

Commenting on the results, Imperial College London professors Rosemary Boyton and Danny Altmann said the results showed lower defenses and were “more worrying” than previous studies.

“All of these data confirm that, if required, for SARS-CoV-2 the prospect of immune protection against natural diseases may not be within our reach and a global vaccination program with high-efficiency vaccines is the lasting solution. , ”They said in a linked comment piece which was also published in the Lancet.