Study: COVID-19 reinfection rare, but likelihood increases with age
Getting diagnosed with coronavirus a second time is mostly uncommon, though the likelihood of reinfection increases in those over the age of 65.
The study, carried out by a team of scientists — including some from Denmark’s Department of Infectious Disease Epidemiology and Prevention — was published this week in the medical journal The Lancet. Their findings confirmed most COVID-19 patients exhibited a stable immunity for six months after the initial infection, with no evidence to suggest it will fade after that point.
“Given what is at stake, the results emphasize how important it is that people adhere to measures implemented to keep themselves and others safe, even if they have already had COVID-19,” study co-author Dr. Steen Ethelberg of the Statens Serum Institut in Denmark said in a statement.
Researchers examined the reinfection rate among 4 million people amid the second surge of COVID-19 between September and Dec. 31, then compared the data to the infection rate during the initial wave from March through May.
Of the 11,068 people who tested positive during the first surge, only 72 tested positive again during the second, according to the study. Younger people showed about 80% protection against repeat infections while the older demographic showed about 47% protection against reinfection.
The findings, published Wednesday, are not entirely shocking, given that the immune system weakens as a person ages.
