BANGKOK — Thailand delayed use of the AstraZeneca vaccine on Friday after several European countries temporarily suspended the jabs following reports of blood clots in some people.

A publicity event with Thai Prime Minister Prayuth Chan-ocha receiving his first shot was canceled with dozens of media attending, less than an hour before the scheduled start. Instead, health officials held a news conference to explain the delay was based on the decision made by Denmark, Austria and others as a precaution. The Danish health authority said Thursday it has no evidence the vaccine was responsible for blood clots.

Other experts pointed out that of the millions of AstraZeneca vaccine shots administered elsewhere, including in Britain, there have been no reported cases of the vaccine causing blood clots or related problems.

Yong Poovorawan, an advisor to Thailand’s vaccination program, said the delay, pending an investigation into the cause of the reported side effect, will not have a big impact on the rollout.

Thailand started its vaccination drive last month with an initial 200,000 doses of China’s Sinovac and 117,000 doses of AstraZeneca, which is also being manufactured locally.

The country aims to inject 10 million doses a month from June, and plans to cover at least half its population by the end of the year, though some say the campaign is too slow and inadequate.