Medical regulators in Britain and the European Union on Wednesday said it was "plausible" that the Oxford-AstraZeneca's coronavirus vaccine is linked to rare but sometimes deadly blood clots, a development that could complicate plans to roll it out around the world. The European Medicines Agency stressed that the benefits of vaccination still outweigh the risks, as thousands of people die of the coronavirus across the continent each day. But British officials advised that adults under 30 be offered alternative vaccines, noting that the calculus is different for young and otherwise healthy people who are at relatively low risk of serious covid-19. Italy and Belgium also put new restrictions on the vaccine for people under 60 and 55 respectively, bringing them in line with other European countries, including Germany and France.