CANBERRA, Australia — Australia has become the latest country to restrict use of the AstraZeneca vaccine by recommending that it not be given to people under age 50.

The announcement came after drug regulators held a series of urgent meetings earlier in the day. That followed advice from the European Medicines Agency that it had found a possible link between the shot and rare blood clots.

Prime Minister Scott Morrison received a series of recommendations from an advisory group on Thursday. Chief among them is that the Pfizer vaccine should now be adopted as the preferred vaccine for people aged under 50.

Such restrictions are closely watched since the vaccine, which is cheaper and easier to store than many others, is critical to global immunization campaigns. It is a pillar of the U.N.-backed program known as COVAX that aims to get vaccines to some of the world’s poorest countries.