TOKYO -- Japanese drugmaker Shionogi will begin a Phase 3 clinical trial on its COVID-19 vaccine this month, mainly in Vietnam and other Asian countries, CEO Isao Teshirogi said Monday.

The clinical trial, which will involve two groups, one given the actual vaccine and the other given a placebo, is aimed at putting its "recombinant protein vaccine" on the list of the World Health Organization-approved vaccines, Teshirogi said at a news conference to discuss the company's earnings. Shionogi is the front-runner in COVID vaccine development in Japan,

Vietnam has agreed to hold a trial in exchange for technology transfer to the country, Teshirogi said.

The placebo-based trial is one of several Phase 3 clinical trials the Osaka-based company is planning to undertake. In Japan, the company will also examine the safety and efficacy of its vaccine compared with those of Pfizer, Moderna and AstraZenaca, which are currently being administered. It will also test the efficacy of the vaccine as a booster shot.

The recombinant protein vaccine uses genetically modified insect cells to produce copies of the COVID-19 spike protein. A similar technology is used by Novavax, Sanofi and GSK in their own vaccine development.

Shionogi hopes to obtain approval from Japanese regulators and make the vaccine available in Japan by the end of March next year, Teshirogi said.

Teshirogi said at a news conference on Nov. 1 that the drugmaker hopes to obtain regulatory approval and make its vaccine available in Japan by the end of March 2022. (Photo by Mitsuru Obe)

Shionogi is also developing an orally administered COVID drug and began a Phase 2/3 trial in Japan in September. Trials of the treatment in Singapore, Vietnam, South Korea and the U.K. are expected to start as early as this month. More than 90% of the test cases may be from overseas, as there are fewer than 300 new COVID cases in Japan a day, Teshirogi said.

He said the trial in Singapore, where 3,000 to 4,000 new cases are reported daily despite more than 80% of its population being fully vaccinated, would provide useful insights for Japan, which also has more than 70% of its population fully vaccinated.

Shionogi's oral drug inhibits the virus's protease, an enzyme essential for the virus's duplication. U.S. drugmakers including Merck are also developing oral drugs. Their drugs target the virus's polymerase, another enzyme used to make copies of the virus.

Shinogi aims to file for regulatory approval in Japan by the end of the year.