U.K. Limits AstraZeneca Covid-19 Vaccine to Over-30s Amid Blood-Clot Concerns

The U.K.’s vaccines advisory body said Wednesday that AstraZeneca PLC’s Covid-19 shot should preferably not be given to patients under 30 following concerns that it might cause potentially deadly blood clots in very rare instances.

Britain’s Medicines and Healthcare products Regulatory Agency said more work is needed to firm up the link between the vaccine and blood clots.

Jonathan Van-Tam, Britain’s deputy chief medical officer, said the pace of Britain’s vaccine rollout shouldn’t be affected by the decision provided currently expected supplies were delivered. The government has said it plans to vaccinate every adult by the end of July.

Also Wednesday, the European Union’s health agency said it had found possible links between the AstraZeneca vaccine and rare blood clots but that the shot’s benefits continue to outweigh the potential risks. The European Medicines Agency said it found no specific risk factors linking the vaccine to the clots.

The AstraZeneca vaccine, which was developed jointly with the University of Oxford, has faced questions about its efficacy and potential side effects even as tens of millions of doses have been administered following safety signoffs in more than 70 countries world-wide.

The British government said last week that 79 severe blood-clotting cases were reported in the U.K. out of 20 million administered doses of the vaccine, according to data as of March 21. Nineteen of the people died, the regulator said.