Seniors who have recovered from Covid cannot presume that they are immune to a second attack, according to a new study that shows that children under 65 are much less susceptible to reinfection.
The study in Denmark found that minors under 65 had about 80% protection for at least six months against the capture of Covid for the second time. But those over 65 had only 47% protection.
The authors of the research, published in the medical journal Lancet, say that this means that it is vital to take measures to protect the elderly, who are also more likely to die from Covid. “Our study confirms what several others seemed to suggest: reinfection with Covid-19 is rare in younger, healthier people, but the elderly are at greater risk of getting it again,” said Dr. Steen Ethelberg of the Statens Serum Institut at Denmark.
“As the elderly are also more likely to have severe symptoms of illness and, unfortunately, to die, our findings make it clear how important it is to implement policies to protect the elderly during the pandemic. Given what is at stake, the results emphasize the importance of people adhering to the measures implemented to keep themselves and other people safe, even if they already have Covid-19. Our insights can also inform policies focused on broader vaccination strategies and the easing of blocking restrictions. “
Denmark has a very comprehensive testing program, with PCR smear tests available to anyone who wants to, with or without symptoms. More than two-thirds of the population, 4 million people, were tested in 2020. The researchers analyzed the proportions of people who tested positive in the first wave, between March and May, and again in the second wave, from September to December. They also analyzed second infections at any time during the pandemic in a group of 2.5 million people.
Professor Rosemary Boyton and Professor Daniel Altmann of Imperial College London say in a newspaper comment that the findings are worrying because case reports previously suggested that reinfection is extremely rare. In that light, “many will find the reported data … on protection against natural infections relatively alarming,” they wrote. “Only 80% protection against reinfection in general, decreasing to 47% in people aged 65 and over, are more worrying figures than those offered by previous studies.”
They say the study reinforces the case for mass immunization programs – including those that contracted Covid in the past.
“These data are all confirmation, if necessary, that for Sars-CoV-2 the hope of protective immunity through natural infections may not be available to us and a global vaccination program with highly effective vaccines is the lasting solution. ”, They wrote.