Daiichi Sankyo Co. and KM Biologics Co. have started clinical trials for COVID-19 vaccines, marking the third and fourth times Japanese pharmaceutical firms have taken the key step toward demonstrating the efficacy of their shots.

But despite hopes that domestically developed vaccines will be available in the near future to help curb the pandemic, the general public is unlikely to have access to them until the year starting April 2022 at the earliest, industry sources say.

Both firms started administering the two-dose vaccines Monday as part of the combined early and middle phases of their clinical trials, which involve healthy adults and people age 65 and over. Daiichi Sankyo, which is co-developing the vaccine with the University of Tokyo’s Institute of Medical Science, aims to speed up the schedule for commercialization, but the official launch is expected to be in 2022 at the earliest.