The UK has received five reports of a specific brain blood clot in people who had had the AstraZeneca coronavirus vaccine, though no causal link has been made with the jab, the medicines regulator has said.
The five people were men aged 19 to 59 who experienced a clot together with low blood platelet count. One of the five has since died.
The Medicines and Healthcare products Regulatory Agency (MHRA) said it was looking at the reports but stressed the events were “extremely rare” and there was a possibility they could have been caused by Covid itself.
It said the cases represented a less than one in a million chance of suffering this type of clot, while the risk of dying from Covid aged 40 to 49 was one in 1000.
The type of clot – cerebral venous sinus thrombosis (CVST) – prevents blood from draining out of the brain.
Ireland suspended use of the jab earlier this week, out of an abundance of caution.
It followed reports of serious clotting in adults in Norway which left four people in hospital.
Irish health minister Stephen Donnelly said it was a “precautionary step”.
The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) said: “We are aware of the action in Ireland.
“We are closely reviewing reports but, given the large number of doses administered and the frequency at which blood clots can occur naturally, the evidence available does not suggest the vaccine is the cause.”