UK reports 7 blood clot deaths among recipients of AstraZeneca jab

The British medicines regulator has disclosed that seven people who had received the Oxford/AstraZeneca Covid-19 vaccine have died after registering the rare blood clotting events that have caused precautionary restrictions to be placed on the jab’s use in several European countries.

The Medicines and Healthcare products Regulatory Agency told the Financial Times it had received 22 reports of cerebral venous sinus thrombosis and eight reports of other thrombosis events that had been coupled with low platelets, leading to seven deaths out of the 18.1m people who had received the AstraZeneca vaccine. 

The unusual combination of blood clots and low platelet levels has previously alarmed some groups of scientists in mainland Europe. Reports of similar incidents have caused France, Sweden, Finland, Canada and most recently Germany to recommend that younger people, who are much more likely to be affected by the condition, avoid the shot. In Norway and Denmark, the vaccine is still suspended.

The MHRA, the European Medicines Agency and the World Health Organization have all said no evidence has been found of a causal link between the vaccine and the condition. They have recommended that governments continue to administer the shot.

The MHRA initially reported the new cases on Thursday, as part of a weekly update on so-called post-vaccination yellow card events, though it did not discuss the fatalities. Following that update, Downing Street said it would keep assessing the evidence as it was collected but that its advice and vaccination strategy remained unchanged.

“We remain absolutely confident in the vaccine,” it said.

Thirty cases of blood clots combined with low platelet counts equates to roughly one case in every 600,000 people who have received the AstraZeneca vaccine. This was a sharp increase from the number of such incidents recorded in the previous MHRA report on 22 March. That showed 4 cases of CVST and no fatalities for the period from January up to 14 March.

All of the reported cases involved people who had received only their first dose of the shot, the MHRA told the FT. “Of the 30 cases in our statement . . . sadly seven have died,” it said.

The UK has not recorded any of the same incidents among people that have received the BioNTech/Pfizer vaccine, the MHRA said.

CVST occurs when blood forms clots in the veins that run from the brain, which is itself a potentially fatal complication. In the most concerning cases, this has been combined with an issue called thrombocytopenia where a patient also presents abnormally low levels of platelets, resulting in heavy bleeding.

In Norway, health officials have reported at least six such cases among 120,000 recipients of the jab, four of whom died. In Germany, 31 cases have been reported after 2.7m vaccinations, including 29 women aged between 20 and 63, and two men aged 36 and 57. Nine of them have died. In the UK the MHRA has not provided information on age or gender for the different cases.

The benefits of Covid-19 vaccine AstraZeneca in preventing Covid-19 infection and its complications continue to outweigh any risks

Dr June Raine, chief executive of the MHRA, reiterated that “the benefits of Covid-19 vaccine AstraZeneca in preventing Covid-19 infection and its complications continue to outweigh any risks and the public should continue to get their vaccine when invited to do so”.

Even if a causal link were to be established, some experts said it would still make sense to continue with vaccinations because the blood clot incidents appeared to be extremely rare.

“No medical intervention is ‘safe’, and the balance of benefit to risk is crucial,” said Professor David Spiegelhalter, chair of the Winton Centre for Risk at the University of Cambridge. “A month’s delay in vaccinating 500,000 people between 44 and 54 would be expected to lead to around 85 severe cases requiring hospitalisation, of which perhaps 5 would die.”

David Werring, professor of clinical neurology at UCL, said the incidence of CVST in the UK was normally around 5 to 15 cases per million people per year. “So the absolute risk of CVST after this vaccine remains extremely low, about 1.5 per million.”

Oxford university and AstraZeneca have said their trials showed the vaccine was safe and effective, and that they are continuing to monitor for side effects as the shot is rolled out.