Countries across the Asia Pacific are demurring on AstraZeneca PLC¡¯s COVID-19 vaccine, or restricting its use, in moves that may delay protection for the region amid concerns that the shot could trigger a rare and potentially deadly blood clotting condition.

After guiding against the vaccine¡¯s use in people under 50 and saying that it didn¡¯t expect shipments from Europe to arrive on time, Australia¡¯s government abandoned a pledge that everyone in the country would receive a first dose by October.

In Hong Kong, officials said they wouldn¡¯t take delivery of the vaccine supply they¡¯ve ordered from the British drugmaker this year, as the city plans to rely on vaccines from BioNTech SE and Sinovac Biotech Ltd.