Almost half of the 1.54 million doses of Pfizer vaccines donated by the United States will be allocated as a booster for 700,000 frontline medical staff countrywide.
The vaccines, which arrived in Thailand yesterday, will be administered to health workers starting next week, either Thursday or Friday.
The jabs will also be provided for other target groups from Aug 9, according to the Department of Disease Control.
All of the 1.54 million doses arrived at Suvarnabhumi airport yesterday morning. Deputy Prime Minister and Public Health Minister Anutin Charnvirakul and senior health officials were at the airport to accept the delivery.
The shipment arrived on flight 3S530 of AeroLogic airlines in refrigerated containers.
Dr Opas Karnkawinpong, chief of the Department of Disease Control, said besides the 700,000 vaccine doses for the health workers, 645,000 doses will be allocated to the elderly and patients with seven underlying conditions, minors from 12 years old, and women who are 12 or more weeks pregnant.
A further 150,000 doses are for expats who are elderly or are suffering from one of seven underlying conditions, pregnant women, and Thai nationals planning to go abroad such as students.
There are also 5,000 doses for research purposes and 40,000 doses to be held in reserve for outbreaks.
Michael Heath, charge d'affaires at the US embassy, said the donation comes with no conditions attached, while adding the distribution of the vaccine is the responsibility of the Thai government.
"However, I would like to note that many Thai government officials recently stressed that they would prioritise the people who are most at risk from Covid-19 and the Delta variant and the people who are most at risk are the people on the frontline such as the healthcare workers, the doctors, nurses and the volunteers dealing directly with the Covid-19 patients," Mr Heath said.
He confirmed a recent statement made by Senator Tammy Duckworth who said that the US would donate an additional 1 million doses, which in total is 2.5 million vaccines from the US.
The brand and shipment date of those jabs have yet to be confirmed.
"I would like to support that the vaccine should be made available to all people in Thailand no matter what nationality," he said, adding that both Thais and foreign residents can transmit the virus.
Meanwhile, Dr Kiattiphum Wongrajit, permanent secretary of the Ministry of Public Health, said that the ministry has planned to allocate 10 million vaccine doses for next month.
He said that they will be able to put more focus on other provinces after Bangkok has achieved vaccination of 61.67% of its population.
Only 18.36% of Thailand's population has been vaccinated.