Canada’s vaccine advisory committee is recommending suspending the use of the AstraZeneca-Oxford COVID-19 vaccine in Canadians under 55, following reports of rare but potentially fatal blood clots in Europe that appear to be connected to the shot. The National Advisory Committee on Immunization (NACI) updated its guidelines to provinces and territories against the use of the vaccine for younger Canadians on Monday over safety concerns.
Health Canada said Monday that 300,000 doses of AstraZeneca vaccine have been administered and no cases of the rare blood clotting adverse events have been reported in Canada, but that it was aware of additional cases that have recently been reported in Europe.
Quebec and Newfoundland and Labrador have suspended the use of the vaccine for anyone below the age of 55, while Prince Edward Island also halted its use of the shot in residents aged 18 to 29 who work directly with the public. Other provinces and territories are expected to follow.
NACI previously recommended earlier this month that Canadians over 65 not receive the shot, despite emerging evidence from around the world demonstrating its ability to prevent severe COVID-19 in older adults.
The decision to halt the use of the vaccine in Canadians under 55 comes after European Medicines Medicines Agency (EMA) investigated 25 cases of the rare blood clots out of about 20 million AstraZeneca shots given. It concluded on March 18 that the benefits from the vaccine far outweigh its possible risks, although a definitive link could not be ruled out.
But 18 of the cases in Europe were of an extremely rare type of blood clot called cerebral venous sinus thrombosis (CVST) — where veins that drain blood from the brain are obstructed and can potentially cause fatal bleeding.
The EMA said on March 18 at least nine deaths have been associated with the adverse events in Europe and the agency is continuing to investigate the situation. Germany’s medical regulator told The Associated Press on Monday it had received reports of 21 cases of rare blood clots in people who had recently received AstraZeneca’s coronavirus vaccine.
The Paul Ehrlich Institute also said that seven people affected by the blood clots have died. It added that of the 21 cases reported in Germany until March 25, 12 also involved an abnormally low level of platelets in the patients’ blood.
Nineteen of the 21 cases were in women ages 20 to 63, while two were in men ages 36 and 57. During the period covered by the reports, some 2.27 million first doses of the AstraZeneca vaccine were administered in Germany.
Bogoch said that the discovery of a potential connection with the vaccine to blood clots, particularly CVST, raised a “red flag” that “warrants further exploration.”
“People should appreciate that not all blood clots are created the same,” he said. “This is a very specific and particular method of blood clotting that likely has an association with the vaccine.”