Young adults previously infected with Covid-19 are still at risk of catching the disease again, according to a study of U.S. military personnel that highlights the importance of vaccinating even those who have tested positive for the virus.
About 10% of 189 people who had been infected once, most of them 18- to 20-year males, later became reinfected, according to a study of 2,346 U.S. Marine Corps members published Thursday in The Lancet Respiratory Medicine journal. The study took place between May and November 2020.