Sinovac-AZ main formula now, says official

The change has not been formally announced, but was discovered accidentally when a government hospital opened registrations for the wrong regimen and had to cancel them, reports the Bangkok Post.

Siriraj Hospital announced its monthly vaccination schedule on Facebook on Thursday (Sept 9). It said it would administer AstraZeneca to people aged 18 or over who had not yet received any COVID vaccine from Sept 25 to Oct 3. Bookings were to be made through its Siriraj Connect mobile application from Sept 10-20.

As people prepared to tap in, the state hospital issued another announcement the next day, apologising for the “inconsistencies”. It said it had to cancel the previous announcement because the policy of the Ministry of Public Health was to give Sinovac as the first shot and AstraZeneca as the second. It promised to open registrations again when it gets hold of the vaccines it needs.

The about-turn has raised questions about what the policy on free vaccinations is now.

Opas Karnkawinpong, director-general of the ministry’s Disease Control Department, clarified on Saturday (Sept 11) that the main regimen was now Sinovac as the first shot and AstraZeneca as the second, effective immediately.

The main reason behind the change, he said, is to speed up vaccinations.

The AstraZeneca-AstraZeneca formula requires triple the waiting time between shots, at 12 weeks, compared to four weeks for the Sinovac-AstraZeneca cocktail, he said.

As authorities want to fully vaccinate as many people as soon as possible in order to slow down the spread of the Delta variant, the change is appropriate, Dr Opas added.

Discussing efficacy, he assured the public that both regimens offered comparable levels of immunity.

The Cabinet on Tuesday approved B4.2 billion to buy 12 million more doses of Sinovac to support the mix-and-match vaccine policy. Besides, unlike other brands, the Chinese vaccine is readily available and can be shipped promptly, government spokesman Thanakorn Wangboonkongchana said at the time.

Dr Opas also reiterated on Saturday that 24mn doses of COVID vaccines would be available: 6mn Sinovac, 10mn AstraZeneca and 8mn Pfizer-BioNtech.

In addition, the Chulabhorn Royal Academy will import another 6mn shots of Sinopharm, an alternative vaccine not on the government’s free programme.

With ample supply, the ministry will speed up vaccinations on 50% of the population in all provinces, including booster doses for those who have received two Sinovac shots and for children aged 12 and up.

As many as 4.8mn Pfizer doses will be made available to students aged 12-17. Parents will be advised about potential risks, which are rare but are higher for mRNA vaccines than for conventional jabs such as Sinovac, and will have to give consent for their children to be inoculated.

As of Thursday, a total of 38.3mn vaccine doses have been administered: 26.6mn first doses 39.7% of the population), 11.6mn second doses (17.3%) and 611,102 third doses.