Risk of Covid reinfection is low - but over-65s are most at risk

Risk of Covid reinfection is low - but over-65s are most at risk (Photo: Shutterstock)
Risk of Covid reinfection is low - but over-65s are most at risk (Photo: Shutterstock)

The majority of people who catch Covid-19 will be protected for at least six months, although those over-65 are more vulnerable to reinfection, according to a new study

An analysis of Covid infections in Denmark found that those aged 65 and over were 47 per cent protected from reinfection, while under-65s were around 80 per cent protected, meaning they are more likely to get the virus again.

Researchers found that the total number of people getting reinfected is very low, with only 0.65 per cent of people returning a positive PCR test twice.

Free mass testing

Researchers looked at data from Denmark’s mass testing regime, which offered free PCR tests to anyone, whether they have symptoms or suspect they’ve been in contact with someone with the virus or not.

Around four million people in Denmark were tested in 2020 - just over two thirds of the population.

Dr Steen Ethelberg, from the Statens Serum Institut in Denmark, said: “Our study confirms what a number of others appeared to suggest: reinfection with Covid-19 is rare in younger, healthy people, but the elderly are at greater risk of catching it again.

“Since older people are also more likely to experience severe disease symptoms, and sadly die, our findings make clear how important it is to implement policies to protect the elderly during the pandemic.

“Given what is at stake, the results emphasise how important it is that people adhere to measures implemented to keep themselves and others safe, even if they have already had Covid-19.

“Our insights could also inform policies focused on wider vaccination strategies and the easing of lockdown restrictions.”

Ongoing analysis is needed

Dr Daniela Michlmayr, from the Staten Serum Institut said: “In our study, we did not identify anything to indicate that protection against reinfection declines within six months of having Covid-19.

“The closely related coronaviruses Sars and Mers have both been shown to confer immune protection against reinfection lasting up to three years, but ongoing analysis of Covid-19 is needed to understand its long-term effects on patients’ chances of becoming infected again.”