A Covid-19 vaccination drive for more than 5.04 million students nationwide starts on Monday, ahead of the new school term which is due to begin in November.
The Education Ministry now aims to fully vaccinate students aged 12 to 18 using the Pfizer Covid-19 vaccine, which is approved for use on children as young as 12.
The ministry will vaccinate students in the 29 provinces in the "dark red" zone first before expanding the drive to other parts of the country.
It is considering giving only one shot to boys amid concerns about a rare form of heart inflammation, following a report of such a case in the United States.
So far, only one such case, a 13-year-old boy who is now recovering in hospital, has been reported in Thailand.
Last week, the ministry announced its plan to reopen schools.
In the first phase, boarding schools which have already taken steps to prevent Covid-19 transmission on their grounds since August, will be allowed to reopen.
In the second phase, schools which have passed an inspection of their facilities will open. Assessments will start this month.
If schools want to pass the assessment, at least 85% of teachers and staff will have to be vaccinated against Covid-19.
