On Monday, Thailand’s National Communicable Disease Committee (NCDC) approved the use of the AstraZeneca vaccine as a second dose for people who have already received just their first dose of the Sinovac vaccine, with an interval of 3-4 weeks between doses.

The British-Swedish AstraZeneca vaccine will also be used as the third “booster” shot for medical personnel, the majority of whom have been inoculated with China’s Sinovac, according to Public Health Minister Anutin Charnvirakul, in his capacity as the chair of the NCDC meeting.

The move comes after several medics and others, fully inoculated with Sinovac’s CoronaVac, were still infected by the virus which causes COVID-19, expert medical findings that the Chinese vaccine is ineffective against the virulent Delta variant and calls for mRNA booster shots for medics who are most at risk of infection.

The Centre for COVID-19 Situation Administration (CCSA) said on Friday that the Pfizer vaccine, donated by the US government, will be administered to medics as third shots, foreign diplomats and others in vulnerable groups, such as the elderly and those with any of the seven specified diseases, as soon as it arrives.

Mr. Anutin also said the ministry aims to inoculate up to one million people aged 60 and over within two weeks, as the vaccination rate among the elderly population remains low.

Thailand has administered about 12.5 million doses of vaccines to date, with over 3.2 million people having received two.

It is not immediately known when the new “mixed” vaccination policy will take effect.