The UK’s medicines watchdog says it has found 30 cases of rare blood clots in people who have had the Oxford-AstraZeneca Covid vaccine.
The Medicines and Healthcare products Regulatory Agency (MHRA) says the risk of having this type of clot is “very small”.
The UK cases were out of more than 18 million doses given as of 24 March.
Fears over clots have led nations such as the Netherlands, Germany, France and Canada to restrict the jab’s use.
The pharmaceutical company AstraZeneca has said international regulators had found the benefits of its jab outweighed risks significantly.
The MHRA, the European Medicines Agency (EMA) and the World Health Organization (WHO) have also said the benefits of taking the vaccine outweigh any risks.
The MHRA said it had received 22 reports of cerebral venous sinus thrombosis (CVST) – where a blood clot forms in the brain – and eight reports of “other thrombosis events with low platelets [the cells involved in clotting]” following use of the Oxford-AstraZeneca jab, out of a total of 18.1 million doses given up to and including 24 March.
The watchdog said the benefits of the Oxford-AstraZeneca vaccine in preventing Covid-19 infection and its complications continued to outweigh any risks, and urged the public to accept the jab when offered it.
In response to the MHRA’s data, Prof Adam Finn, a member of the Joint Committee on Vaccination and Immunisation (JCVI), insisted taking the vaccine was “by far the safest choice” to minimise the risk of serious illness or death from Covid-19.
He said: “The extreme rarity of these events in the context of the many millions of vaccine doses that have been administered means that the risk-benefit decision facing people who are invited to receive Covid-19 vaccines is very straightforward: receiving the vaccine is by far the safest choice in terms of minimising individual risk of serious illness or death.”
Meanwhile, the MHRA said there had been no reports of blood clots following use of the Pfizer-BioNTech vaccine.
As of 21 March, an estimated 10.8 million first doses of the Pfizer-BioNTech jab had been administered in the UK, the regulator said. It added that around 2.2 million second doses, mostly the Pfizer-BioNTech vaccine, had been administered.
More than 31.3 million people in the UK have received a first dose of a coronavirus vaccine, and more than 4.9 million have had a second dose, according to Friday’s daily government figures.