A new Swedish study shows that the risk of dying decreased for elderly and frail people after the fourth dose of vaccine against covid-19.
Between days 7 and 60 after the 80-plus had received their fourth dose, they were 71 percent less likely to die than those who had only received three doses.
The researchers behind the study hope that knowledge will increase – about whether more top-up doses are needed.
See more about the impact in the player above.