Earlier, the National Expanded Program on Immunization announced Vietnam would receive 1.373 million doses of the vaccine via the Covax program with support from UNICEF on March 25, and the rest in April.

Covax, or Global Covid-19 Vaccine Facility, is a global mechanism for the development, manufacture and procurement of Covid-19 vaccine candidates, facilitating and supporting member countries to access vaccines as they become available.

Around 33 million doses that Covax pledged for Vietnam in the second half of this year may be delayed until next year.

Professor Dang Duc Anh, director of the National Institute of Hygiene and Epidemiology and program head, said 29.87 million doses of the vaccine Vietnam had ordered via Vietnam Vaccine JSC would not arrive in the country in the second and third quarter as previously planned.

Anh said the delay of the vaccine delivery was due to production capability problems.

In addition, the number of vaccine manufacturers meeting WHO pre-assessment standards is still small while the vaccine production capacity of manufacturers is limited, he added.

Some advanced countries like the U.S., U.K., and Europe had previously ordered large quantities of the vaccine right from the research stage, leading to a shortage of vaccine supply globally, making it hard for developing countries like Vietnam to access vaccine sources, Anh held.

Vietnam is expected to acquire 150 million Covid-19 vaccine doses from foreign and domestic sources by 2022.

Besides the deal with AstraZeneca, Vietnam is also stepping up negotiations with the U.S.'s Pfizer and Moderna, along with other vaccine manufacturers in Russia and China.

The Southeast Asian country began its mass vaccination campaign on March 8. So far, 36,082 medical staff and frontline workers in 16 localities have received the first shot of the vaccine developed by the British-Swedish company AstraZeneca.

Though there has been one case of third-degree and five cases of second-degree anaphylaxis, all those vaccinated are now in stable condition, allowing the country to proceed with its inoculation program.

Vietnam expects to start producing its own Covid-19 vaccine by the end of the third quarter, according to the ministry.