The government has abandoned a plan for a 16-week gap between doses of AstraZeneca coronavirus vaccine and will opt for a shorter interval of 10 to 12 weeks instead, a senior health official said on Friday.
Authorities had sought to vaccinate more people faster by stretching the gap between shots to 16 weeks, beyond the 12-week maximum approved by the European Medicines Agency.
A 16-week interval has not been tested in human trials.
But Sophon Mekthon, assistant to the public health minister, told Reuters that the communicable disease committee wanted to revert to the previous interval, adding that it could still be extended in future if necessary.
The country started its mass Covid immunisation campaign last week and has administered 7.2 million doses since February.
The campaign has got off to a bumpy start with vaccine quantities falling short of projections, and disputes over allocation.
AstraZeneca has contracted with Siam Bioscience to manufacture the jabs locally, but it has taken the company some time to get up to speed. This is also causing delays in shipments to Taiwan, Malaysia and the Philippines.
Public Health Minister Anutin Charnvirakul said on Friday that the government would receive 10 million AstraZeneca doses monthly from July until its quota of 61 million doses is met. The country has also been using the Sinovac vaccine from China.
All told, the government has secured 105.5 million doses of various vaccine brands so far and will procure 50 million more next year, authorities have said.