The Ministry of Public Health is pledging to have 30 million Thais vaccinated against Covid-19 by the end of the year.
"If everything goes to plan, we can start administering at least five million doses per month and later, up to 10 million doses per month, to complete 61 million doses in 2021," Dr Opas Karnkawinpong, chief of the Department of Disease Control (DDC), said on Monday.
"This is the largest vaccination programme in our history and we need to get all our staff ready to do the job."
The DDC is preparing to soon launch the mammoth three-phase programme, with two million doses given by the end of next month. The second and third phases will follow from June onwards, using 61 million doses of the Oxford University/AstraZeneca vaccine.
The way ahead has become clearer since news broke that Chinese health officials recently approved the vaccine for general public use, paving the way for the Thai Food and Drug Administration (FDA) to speedily approve its second vaccine for emergency use.
The FDA last month already approved the Covid-19 vaccine developed by Oxford University/AstraZeneca. The first 200,000 doses should arrive this month and will be given to people in high-risk areas, especially Samut Sakhon province, the epicentre of the recent infection outbreak.
It is envisaged that 20,000 doses of the initial batch will be administered to frontline health workers. The remaining doses will be given to high-risk groups in Samut Sakhon, including those aged over 60, patients with non-communicable diseases, and vulnerable groups.
A total of 600,000 doses are planned next month for high-risk people in maximum-control provinces, plus provinces bordering Myanmar and areas in the South; 200,000 doses will be used as second jabs for those in the first group.
One million more doses are due to arrive in April, of which 600,000 will be given as second jabs and 400,000 reserved for those in urgent need.
Dr Opas was confident 50% of the population would be vaccinated this year and said the injections would be performed at thousands of public and community hospitals.
Central storage sites at the Department of Disease Control and the Government Pharmaceutical Organization (GPO) will be responsible for distributing the vaccine nationwide.
The Public Health Ministry has also developed what it is calling an Adverse Event Following Immunisation (AEFI), a mandatory process to trace the vaccine's side-effects and efficacy.
Public Health Minister Anutin Charnvirakul said the country will use more than one or two vaccines.