Canada and three cities in Germany have suspended the use of the Oxford-AstraZeneca COVID-19 vaccine for younger people over fears it might be linked to blood clots.
The National Advisory Committee on Immunization of Canada recommended this week the British-made vaccine not be provided to citizens younger than 55.
Following 31 cases of rare blood clots in people who had recently received the jab, German cities Berlin, Munich and Brandenburg have suspended the shot for people under the age of 60. Nine of those people had died.
In March, several European countries briefly suspended the vaccine owing to evidence of a rare form of blood clot in the head known as sinus vein thrombosis.
The European Medicines Agency said the benefits of the vaccine outweighed the risks but recommended warnings about possible side effects should be made known to patients and doctors.
Most European Union countries have resumed the use of the vaccine.
"There is substantial uncertainty about the benefit of providing AstraZeneca vaccines to adults under 55 given the potential risks," the vice chairperson of the Candian committee Shelley Deeks said.
Although three German cities have already stopped administering the vaccine to those under 60, the rest of the country is considering following suit, according to a draft resolution made by Germany's standing vaccination commission and obtained by local newspaper Der Tagesspiegel.
The draft recommends that no one under 60, male or female, get the AstraZeneca vaccine, but use below that age "remains possible at the medical discretion and after careful clarification, if the individual risk is accepted," the publication reported.
While vaccine-induced blood clots are rare, health officials discovered they disproportionately affected young people, CTV reported.
The AstraZeneca vaccine, which has become an important weapon in Europe's immunization campaign, has yet to be licensed for use in the U.S. but is estimated to be 76% effective, according to the manufacturer.
AstraZeneca said it planned to apply for Food and Drug Administration emergency use authorization in the U.S. soon.
