The number of people getting the first dose of their Covid-19 jab will be “constrained” as a result of a “significant” reduction in the vaccine supply available, health officials have said. NHS leaders said there will be a “significant reduction” in the vaccine supply from the week beginning March 29. A letter to regional NHS bosses says that the reduction will continue for a “four-week period”. As a result, health leaders have said that people under the age of 50 should only get the jab if they are in a priority group for the vaccine. Health Secretary Matt Hancock told the Downing Street press conference that the nation was “on course” to meet the target of offering a first dose to all over-50s by April 15.