Thailand hopes this lot will include the new formulation Pfizer is developing for children.
Government spokesman Thanakorn Wangboonkongchana said the purchase agreement between Pfizer-BioNTech and the Department of Disease Control is being amended to include the new order.
Including this order, Thailand will have bought 60 million doses of the Covid-19 vaccine from Pfizer-BioNTech so far, he said.