The potential vaccine, currently developed by Vaccine and Biological Production No. 1 (Vabiotech), has produced "high immunogenicity," said Mac Van Trong, a member of the company research team.

Immunogenicity is the ability of a foreign substance, such as an antigen, to provoke an immune response in the body of an animal.

The vaccine was first tested on 50 mice last month, though the project had commenced in February. Serum samples from the 50 treated mice were later taken, and sent to the National Institute of Hygiene and Epidemiology on May 15 and May 29 for evaluation.

The institute later said the samples succeeded in producing an antibody response, some to "quite high levels," said Trong.

Nguyen Le Khanh Hang, deputy head of the institute viral department, said findings would serve as "the foundation to develop a complete vaccine."

With these results, Vabiotech has moved the project's first phase forward by two months, the most important period in vaccine development.

In its second phase, the trial vaccine would be developed into a complete and stable version qualified to be used on humans.

The research team would also develop commercial production procedures for mass-production, including up to tens of millions of units.

"We would need 9-12 more months to complete the vaccine, but we’re trying to shorten this time frame. Even then, compared to the average period of 10 years to produce a normal vaccine, 18-24 months is already a considerable achievement," Trong said.

Do Tuan Dat, president of Vabiotech, said the acelerated vaccine development phase could be attributed to the use of viral vectors instead of inactivated or weakened viruses. Viral vectors are tools used to deliver genetic material into cells.

Dat said the new tech supports high production efficiency and does not depend on the culturing of whole pathogens, making them ideal for creating pandemic vaccines.

The project was funded VND8 billion ($345,216), including sponsorship from Vingroup Innovation Foundation (VinIF), operated by conglomerate Vingroup.

"Thanks to the funds, we have been able to upgrade our cell culture system Bioreactor, which was first equipped 10  years ago. This new model is more responsive to the viral vector technology we’re using," said Dat.

Hundreds of Covid-19 vaccine development projects are being carried out worldwide, with over a dozen vaccines being tested on humans. There are currently no approved treatments for Covid-19.

Vietnam has recorded 352 Covid-19 cases so far, with 23 active cases left and no deaths. No community transmission has been recorded in over two months.