Thailand has begun rolling out booster shots in a bid to reopen the country to tourism nationwide. Around ten percent of the population has received two doses of Chinese vaccines.
Health officials say people who have received the Sinovac vaccine can get the AstraZeneca vaccine.
More than three million Thais are eligible.
Officials say the objective is to boost immunity.
The government says they will administer one million vaccine doses and booster shots on Friday, which is a holiday to commemorate development of modern medicine.
The booster program comes as Thailand hopes to resume accepting overseas visitors nationwide.
But only 23 percent of Thais are fully vaccinated.
Health officials want to raise that number to 70 percent by the end of the year.