The majority of people who have had COVID-19 are protected from getting it again for at least six months, a study published on Wednesday showed, but older people are more prone to reinfection than younger people.
The study, appearing in the Lancet medical journal, found that just 0.65% of patients tested positive a second time for COVID-19 after previously being infected during Denmark's first and second waves. That was much lower than the 3.27% who were positive for the virus using highly accurate PCR tests after initially being negative. However, the study found that people over the age of 65 had only 47% protection against repeat infection, compared to 80% protection for younger people.
"These data are all confirmation, if it were needed, that for SARS-CoV-2 the hope of protective immunity through natural infections might not be within our reach and a global vaccination programme with high efficacy vaccines is the enduring solution," Imperial College London professors Rosemary Boyton and Danny Altmann said in a linked comment piece also published in the Lancet.