According to the MoPH (Ministry of Public Health, Thailand), you are considered fully vaccinated if:
- Got a second dose of a 2-dose vaccine no less than 14 days before your travel date to Thailand.
- Got get a single-dose vaccine no less than 14 days before your travel date to Thailand.
- In case of mix-and-match vaccines, you should get your second dose of a different vaccine within the recommended interval of the first vaccine no less than 14 days before your travel date to Thailand.
Please visit https://www.tatnews.org/2022/06/covid-19-vaccine-guide-for-travellers-to-thailand/ for more information