Britain's medicines regulator said there had been five cases of a rare type of blood clot in the brain among 11 million given AstraZeneca's COVID-19 vaccine but said that it found the benefits of the shot far outweigh any possible risks.
Concerns about reports of blood clots, along with low platelet levels, have led to some European countries including Germany to pause the rollout of the shot while the cases are investigated.
However, Britain's Medicines and Healthcare products Regulatory Agency (MHRA) said that use of the vaccine should continue while five reports were investigated, and one official said that the rollout would likely continue even if a link was proved.
"There is no evidence that blood clots in veins is occurring more than would be expected in the absence of vaccination, for either vaccine," said June Raine, MHRA Chief Executive, referring to AstraZeneca and Pfizer shots.