Covid-19 vaccine booster shots will be administered to millions of Thais who have already received two shots, starting from late next month.

According to Department of Disease Control (DDC) director-general Opas Karnkawinpong, the Public Health Ministry's subcommittee on Covid-19 vaccination agreed the booster shots will be given to Thais from late September to October.

As to vaccines made available as booster jabs, Dr Opas said, "Which vaccine type to be used depends on the availability of the vaccine supply at that time.” He added that an estimated 3 million people who have already received two vaccine doses are expected to receive the booster shots.

A source at the ministry said AstraZeneca and Pfizer vaccines will initially serve as the booster shots because by that time there will be enough supply from the two manufacturers.

Among the 3 million people to get booster shots, many of them are likely to be those who will have already received two shots of Sinovac vaccine at least three months previously, the source said.

In the meantime, permanent secretary for public health Kiattiphum Wongrajit said on Sunday the latest wave of Covid-19 infections shows some signs of slowing down.

As a result, hospital bed occupancy rates in Bangkok and surrounding provinces have dropped, particularly among green- and yellow-coded patients with mild symptoms, he said.