Thailand is tentatively set to extend its “mix and match” approach to COVID-19 mass vaccination in October, using the AstraZeneca viral vector vaccine as the first dose, followed by a dose of the Pfizer mRNA vaccine 4-12 weeks later. About 10 million doses of Pfizer-BioNTech are expected to arrive monthly, said Dr Sophon Iamsirithavorn, deputy director-general of the Disease Control Department today (Friday).
He said that the combination of AstraZeneca and Pfizer is the second such adaptation of inoculation regimens by the Thai health authorities, following the combined use of Sinovac and AstraZeneca, with doses given 3 to 4 weeks apart, which was recommended by the country’s committee of the Medical and Health Emergency Operations Centre on August 25th.
He maintained that the recommendation is based on data derived from new technologies and research conducted both abroad and in Thailand, including initial research papers on the safety and immune responses in the mixed use of Sinovac and AstraZeneca vaccines from the Siriraj Clinical Research Centre at Chulalongkorn University.
Dr. Sophon said that the two “mix and match” approaches will be administered to people aged 18 and over.
Moreover, he said a booster shot, using either AstraZeneca or Pfizer, will be given to unvaccinated patients who have recovered from COVID-19 for between one and three months, those not fully inoculated or who were inoculated less than two weeks before falling sick with the disease.
He said that the earlier target, to inoculate up to 70% of Thailand’s population this year, may not be sufficient to achieve herd immunity and may have to be increased due to the Delta variant.
Between now and the end of the year, six million doses of Sinovac are expected to arrive. 7.3- 8 million doses AstraZeneca will arrive in September, 10 million in October and 13 million doses in both November and December and 8-10 million doses of Pfizer per month from October to December.
