Prime Minister Hun Sen has reminded civil servants and government officials as well as the general public who have already received first and second doses of the AstraZeneca vaccines that they should not use that vaccine again for their third, booster shot.

Cambodia is starting to administer the third dose to frontline workers and officials at the national level in an attempt to prevent the spread of the Delta variant. Hun Sen said last week that those who have been vaccinated with Sinovac or Sinopharm will get AstraZeneca as their booster jab and vice versa.

However, in an audio message released on August 9, he said that in recent days there have been many requests from those who have already been vaccinated with AstraZeneca who want to use it again for their third dose.

“I would like to clarify this matter in order to avoid difficulties. The country itself is facing great difficulties so don’t make things even more difficult by pushing this issue,” he said.

He said there are two problems that make providing AstraZeneca to them again impossible. The first issue is that there is no clear research yet on how long the interval between second and third doses should be for AstraZeneca. Only booster shots using Sinopharm and Sinovac vaccines have been studied by the government and the Ministry of Health.

The second problem is that the government does not have enough AstraZeneca vaccines to cover everyone in this manner. The vaccines they have in inventory now can only be administered to frontline officials who were previously vaccinated with the Sinovac or Sinopharm vaccines.

“I am ordering the procurement commission to acquire more of the AstraZeneca vaccines for those who have already been vaccinated with the AstraZeneca vaccines,” he stated, adding that people who had not received their first dose but come to request AstraZeneca will not vaccinated.

National Covid-19 vaccination commission head Or Vandine has recently told reporters that recipients of the Sinopharm and Sinovac vaccines will get booster shots with the AstraZeneca vaccines between six and eight months after their first doses.

A recent article regarding mixed vaccines regimens published in the science journal Nature said that using a different vaccine for the booster shot can be beneficial because there is some evidence to indicate that it bolsters the body’s immune response more than simply utilising the same vaccines for all three doses, though further research is necessary to confirm this.

The commission on August 9 notified frontline state and private doctors, national and sub-national civil servants in Phnom Penh about their eligibility to receive booster shots of the AstraZeneca vaccines.

The notice said the ministry officials who had their first and second doses using Sinovac or Sinopharm vaccines can get booster shots of AstraZeneca at designated hospitals in Phnom Penh beginning August 12.