Takeda Pharmaceutical Co. said Thursday it has begun clinical trials in Japan of a COVID-19 vaccine candidate by U.S. biotech firm Moderna Inc. with an eye to distributing it in the first half of this year.

Takeda, which is undertaking clinical trials and distribution in Japan of the U.S. company's vaccine known as mRNA-1273, will target 200 adults in the study. The drugmaker is planning to provide 50 million doses, or enough for 25 million people after obtaining regulatory approval. Each person would need two doses of the COVID-19 vaccine.

Japan is struggling to cope with a resurgence in coronavirus cases, with the first vaccine rollout yet to begin. U.S. pharmaceutical giant Pfizer Inc. has applied for Japanese government approval for its coronavirus vaccine and Britain's AstraZeneca Plc has begun a clinical study of its vaccine in Japan.

The government has agreed to secure 144 million vaccine doses from Pfizer and 120 million from AstraZeneca. Combined with Moderna's 50 million doses, the total would be enough for 157 million people, according to Japan's health ministry. Japan has a population of about 126 million.