Covid-19 vaccines have saved more than 112,000 lives and averted 24 million cases of the disease, British officials said on Tuesday as they recommended all vulnerable people, frontline health staff and those aged over 50 be offered a booster shot.

The Joint Committee on Vaccination and Immunisation's recommendation of a third dose six months after a second shot, paves the way for a broad revaccination programme in Britain, which has one of the world's highest death tolls from Covid-19...