Germany is suspending routine use of the Oxford-AstraZeneca Covid-19 vaccine for people aged below 60 because of a risk of rare blood clots.
The German medicines regulator found 31 cases of a type of rare blood clot among the nearly 2.7 million people who had received the vaccine in Germany.
Canada earlier suspended use of the AstraZeneca jab in people under 55.
AstraZeneca said international regulators had found the benefits of its jab outweighed risks significantly.
It said it was continuing to analyse its database to understand “whether these very rare cases of blood clots associated with thrombocytopenia occur any more commonly than would be expected naturally in a population of millions of people”.
“We will continue to work with German authorities to address any questions they may have,” it added.
The EU and UK medicine regulators both backed the vaccine after previous cautionary suspensions in Europe this month.
In the UK, a government spokesperson said: “The Oxford/AstraZeneca vaccine is safe, effective and has already saved thousands of lives in this country. As the UK’s independent regulator has said, when people are called forward, they should get the jab.
“Over 30 million people have already received their first dose of a vaccine, and we are on track to offer jabs to all over-50s by 15 April and all adults by the end of July.”
AstraZeneca’s product is one of the most widely used coronavirus vaccines in the West, and is meant to be supplied on a not-for-profit basis to the developing world.
The EU’s rollout of its vaccination programme has been dogged by delays because of delivery and production problems, and Germany is among several states now fearing a third wave of infections.