Thailand became the latest country to signal waning confidence in a Chinese vaccine against the highly contagious Delta variant, saying it would offer booster shots of Western doses to healthcare workers.
Healthcare workers who received two doses of the vaccine developed by Sinovac Biotech Ltd. would be given a third shot made by either Pfizer Inc. and BioNTech SE or AstraZeneca PLC, Thailand’s health ministry said Monday. Those who had only one dose would receive AstraZeneca as their second.
The decision to mix the vaccines makes Thailand the latest country to show reservations about whether Chinese vaccines work well enough to protect medical workers against the Delta variant, which was first detected in India and is thought to be far more contagious than earlier versions of the virus. The strain has spread to at least 98 countries.
Indonesia said last week that it would offer medical workers a booster shot from Moderna Inc. Around 90% of the country’s medical staff have received two doses of the Sinovac vaccine, but hundreds have fallen ill from Covid-19, reducing medical manpower amid a surge of the virus, according to Indonesia’s health ministry and doctors’ groups.
Sinovac didn’t respond to a request for comment.