China’s coronavirus vaccines were supposed to deliver a geopolitical win that showcased the country’s scientific prowess and generosity. Instead, in some places, they have set off a backlash.

Officials in Brazil and Turkey have complained that Chinese companies have been slow to ship the doses and ingredients. Disclosures about the Chinese vaccines have been slow and spotty. The few announcements that have trickled out suggest that China’s vaccines, while considered effective, cannot stop the virus as well as those developed by Pfizer and Moderna, the American drugmakers.

In the Philippines, some lawmakers have criticized the government’s decision to buy a vaccine made by a Chinese company, Sinovac. Officials in Malaysia and Singapore, which both ordered doses from Sinovac, have had to reassure their citizens that they would approve a vaccine only if it had been proved safe and effective.