In a decision issued by deputy minister of health Truong Quoc Cuong on the ministry's distribution plan for the incoming 745,000 Pfizer vaccine doses purchased using the national budget, the ministry said those who have been given their first Covid-19 vaccine shot by AstraZeneca would be prioritized to receive their second shot with the Pfizer vaccine about 8-12 weeks after the first shot.

The decision would only be applicable if the ones to be vaccinated consent to it. For those who have yet to receive any Covid-19 vaccine shot, the Pfizer one would be prioritized for use as well, according to the decision.

While the Pfizer vaccine doses would be distributed to all 63 localities of Vietnam, most of them would end up in HCMC, Hanoi, Binh Duong and Dong Nai, which are either major cities or experiencing severe Covid-19 outbreaks. Binh Duong and Dong Nai Provinces bordering HCMC are among the country's biggest industrial hubs.

HCMC in particular would receive around 55,000 doses, Hanoi 38,000, and the southern Binh Duong and Dong Nai 25,000 each. Most other localities would receive around 5,850 doses each.

Among the 745,000 Pfizer vaccine doses to be received, Vietnam has only received over 97,000 so far. The rest would arrive within this month, though their exact dates have yet to be confirmed.

It is the first time Vietnam allows mixing different types of Covid-19 vaccines through multiple shots, though the decision has already been observed in several countries around the world.

Thailand for example said on Tuesday it would provide its people their third shots of Covid-19 vaccine by AstraZeneca following two shots by China's Sinovac after it recorded coronavirus infections even on fully vaccinated individuals with the Sinovac vaccine.

German chancellor Angela Merkel received her second Covid-19 vaccine shot by Moderna in June, two months after she received her first shot by AstraZeneca.

However, the WHO on Monday advised against people mixing and matching Covid-19 vaccines from different manufacturers, calling it a "dangerous trend" since there was little data available about the health impact, Reuters reported.

Vietnam has vaccinated over four million people with at least one shot of the AstraZeneca Covid-19 vaccine, with over 280,000 having received two shots.