Doctors from around the world fear a "powerful" new covid strain is capable of re-infecting patients within weeks of them recovering from the virus.
BA.5 has become the new dominant infection in the United States and in other countries. Previously, medics have found those who have been infected with covid then have a level of immunity in the weeks afterwards.
However BA.5 has cast doubt on the notion, with patients reporting falling positive again within a short while of recovering from coronavirus, the Mirror reports.
