A new Covid strain could re-infect people within weeks of them recovering from the virus, doctors from around the world fear.
Medics have long found those who are infected with Covid then have a level of immunity in the weeks afterwards, making it difficult to become re-infected with the virus for some time.
However BA.5, which has become the new dominant infection in the United States, has cast doubt on the notion, with people reporting testing positive again within a short while of recovering from Covid, The Mirror reports.
