Japanese drugmaker Daiichi Sankyo Co. said Thursday it expects to launch its COVID-19 vaccine in Japan by the end of 2022 after studies that started in March yielded positive results.

The company plans to next month accelerate the pace of the trial, aiming to begin by March the final stage of study on its messenger RNA vaccine, the same type already developed by overseas companies including Pfizer Inc. and Moderna Inc.

The trial conducted on 142 people aged 20 or older confirmed vaccine-induced antibody responses, with no safety issues observed, Daiichi Sankyo said.

It also was shown to inhibit mutations of the Delta variant in animal tests conducted in collaboration with the University of Tokyo, it said.

The company said it is consulting with relevant authorities about beginning a clinical study for assessing the effectiveness of a booster dose of the vaccine in January.