Under-30s are to be offered an alternative Covid jab to the AstraZeneca vaccine due to the evidence linking it to rare blood clots, the UK's vaccine advisory body says.
A review by drugs regulator MHRA found by the end of March 79 people in the UK had suffered rare blood clots after vaccination - 19 of whom had died.
The regulator said this was not proof the jab had caused the clots.
But it said the link was getting firmer.
Dr June Raine, of the MHRA, said the side-effects were "extremely rare" - and more work was going to identify if the vaccine was definitely causing the clots.
"The balance of benefits and known risks is still very favourable for the majority of people."
But she said for younger age groups it was more "finely balanced".
She added: "The public's safety is at the forefront of our minds."
The review prompted the government's vaccine advisory group, the JCVI, to recommend that people aged 18 to 29 be offered an alternative vaccine where available.
People who have had their first dose of the AstraZeneca vaccine should still get their second dose. Only those who suffered one of these rare blood clots after the first dose should not get vaccinated, the MHRA said.
People with blood disorders that leave them at risk of clotting should discuss the benefits and risks of vaccination with their doctor before going for a jab.
Nearly two-thirds of the cases of rare clots were seen in women. The people who died were aged between 18 and 79.
However, it was not possible to identify whether age or gender made people more at risk of these rare blood clots.
