The data suggest that those who have contracted the virus should still be vaccinated.
Photographer: Nathan Laine / Bloomberg
Photographer: Nathan Laine / Bloomberg
Older people are at greater risk of contracting Covid-19 again after recovering from a previous bout of the virus, a new study shows.
Although most people are unlikely to get the disease again for at least six months, the elderly are more likely to redefine, according to results published Wednesday in the Lancet. A study of test results in Denmark last year showed that those under 65 who were on Covid were about 80% protected from getting it again. Protection fell to 47% for those 65 and older.
The data suggest that those who have contracted the virus should still be vaccinated, the authors said. Natural protection cannot be relied upon, especially for the elderly at risk of serious disease. The Danish analysis focused on the original coronavirus snout and did not evaluate any new mutations that are thought to be more susceptible.
Why the mutated coronavirus variants are so worrying: QuickTake
“Our findings highlight the importance of implementing policies to protect the elderly at the time of the pandemic,” even if they already had Covid-19, Steen Ethelberg, a senior researcher from the Statens Serum Institut in Copenhagen, said in a statement. “Our comments could inform policies aimed at broader vaccination strategies and relaxing lock-in restrictions.”
The authors of the study analyzed data collected as part of Denmark’s national SARS-CoV-2 validation strategy. More than two-thirds of the population, or about 4 million people, have been diagnosed over time spanning 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% – achieved a positive result after a previous negative one.
Based on results from other studies, there was no evidence that protection against relapse decreased within six months, the authors said. However, since the virus was only identified in December 2019, the total duration of immune transmission provided by infection remains to be determined. It was also not possible to assess whether the severity of the symptoms affected a patient’s level of immunity, they wrote.
“All of this data provides evidence, if required, for SARS-CoV-2 hope immunity through natural diseases may not be within our reach and a A global vaccination program with high-efficiency vaccines is the lasting solution, ”wrote Professors Rosemary Boyton and Daniel Altmann of Imperial College London in a comment linked to the study.