China’s Sinovac Biotech Ltd launched on Tuesday a late-stage human trial involving as many as 1,620 patients in Indonesia for a COVID-19 vaccine candidate that it is developing with Indonesian state-owned peer Bio Farma.

The candidate, known as CoronaVac and previously PiCoVacc, is among few potential vaccines that have entered late-stage trials for a large-scale study to gather proof of efficacy for regulatory approval.

CoronaVac is already undergoing a late-stage trial in Brazil slated for as many as 9,000 people.

A ceremony for the launch on Tuesday in Bandung, West Java, was attended by Indonesia’s President Joko Widodo.

“The threat of COVID-19 will not subside until a vaccine is given to all the people,” Widodo said.

Sinovac expects to also test the vaccine candidate in Bangladesh.

Separately, Sinovac late on Monday released details from a mid-stage, or Phase 2, study in which it said the vaccine candidate appeared to be safe and induced detectable antibody-based immune responses in subjects.

In the Phase 2 clinical trial involving 600 participants in China, the candidate did not cause any serious side effect and the rate of fever was relatively low compared with other COVID-19 candidates, the paper showed ahead of peer review.

Sinovac has to test its vaccine abroad because China is no longer a satisfactory site for late-stage trials due to the low number of new infection cases.