Osaka-based drugmaker Shionogi & Co. said its experimental COVID-19 vaccine was found safe and effective in a study, potentially creating an indigenous supply source for the nation as it races to complete a booster drive in hopes of curbing future outbreaks.

The recombinant protein-based vaccine that was being tested as a booster shot met its primary endpoint in the Phase 2/3 trials, Shionogi said in a statement Friday announcing the interim report*s findings. There were no serious treatment-related adverse events, deaths or adverse events of special interest, it said.

The data support regulatory approval of the vaccine that could bolster the government*s efforts to tackle the virus that has already infected more than 5 million people in the country and killed more than 24,000. The world*s third-largest economy currently relies on shots from Pfizer Inc. and Moderna Inc. for the bulk of its supplies.