Past Covid infection ‘does not fully protect young people against reinfection'
PREVIOUS coronavirus infection does not fully protect young people against reinfection, research suggests.
Researchers said that despite previous infection and the presence of antibodies, vaccination is still necessary to boost immune responses, prevent reinfection and reduce transmission.
They added that young people should take up the vaccine whenever possible.
According to an observational study of more than 3,000 healthy members of the US Marine Corps, most of whom were aged 18-20, between May and November 2020, around 10 per cent (19 out of 189) of participants who had previously been infected with Sars-CoV-2 (seropositive) became reinfected.
This was compared with new infections in 50 per cent (1,079 out of 2,247) of participants who had not previously been infected (seronegative).
Although the study was in young, fit, mostly male recruits, the researchers believe the risk of reinfection will apply to many young people.
However, the exact rates of reinfection will not be applicable in other settings, because of the crowded living conditions on a military base and close personal contact required for basic training likely to contribute to a higher overall infection rate than elsewhere.
Professor Stuart Sealfon, of Icahn School of Medicine at Mount Sinai, New York, and senior author of the study, said: “As vaccine rollouts continue to gain momentum it is important to remember that, despite a prior Covid-19 infection, young people can catch the virus again and may still transmit it to others.
“Immunity is not guaranteed by past infection, and vaccinations that provide additional protection are still needed for those who have had Covid-19.”