U.K. study rules out link to some blood clots from AstraZeneca’s COVID-19 vaccine

OTTAWA — The United Kingdom’s drug regulator says a “rigorous scientific review” has ruled out the Oxford-AstraZeneca vaccine as the cause of blood clots in veins but is doing a more detailed study looking at blood clots in the brain.

The U.K. Medicines and Healthcare Products Regulatory Agency says its advice remains that the benefits of the COVID-19 vaccine outweigh any risks.

Health Canada officials are currently attending a meeting of the European Medicines Agency, which is set to issue a report on blood clots and the AstraZeneca vaccine today.

Many European countries halted use of the AstraZeneca vaccine after there were reports of blood clots in about three dozen patients.

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Deputy chief public health officer Dr. Howard Njoo says Canada is monitoring all the evidence closely.

Health Canada has so far said the vaccine’s benefits are strong and has not seen evidence to link the vaccine to blood clots in a small number of patients after they got it.

“The fact is that all four COVID-19 vaccines authorized by Health Canada meet our country’s high standards for safety, and provide a high degree of protection against severe illness and death related to COVID-19,” said Njoo.

The U.K. review looked at reports of cases of blood clots, hospital admission records and doctor’s patient files and concluded the patients who developed blood clots in veins are not caused by the vaccine.

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They are looking more closely now at five reports in the U.K. of patients developed a rare blood clot in the brain, and lowered platelet counts following vaccination, but said the issue can occur naturally and there is no proven link to the vaccine.

Canadian provinces began administering 500,000 doses of the AstraZeneca vaccine last week. Canada’s doses are not made in the same place as the European or U.K. doses.

Dr. Supriya Sharma, the chief medical adviser at Health Canada, said last week there was no biological explanation to show a link between the vaccine and blood clots.

Thrombosis Canada issued a statement March 11 saying in general vaccines are not linked to the development of blood clots and it had no evidence that the AstraZeneca vaccine was any different.

AstraZeneca said it reviewed the safety records of 17 million patients who received the vaccine in Europe and the U.K. and found no causal link between it and blood clots.