A man walks past a signpost of India's Serum Institute, the world's largest maker of vaccines, which is developing a vaccine against the coronavirus disease (COVID-19) at its laboratory in Pune, India, May 18, 2020. REUTERS/Euan Rocha

Serum Institute of India has received Indian regulatory approval to resume local clinical trials of AstraZeneca’s potential COVID-19 vaccine, a source familiar with the matter said on Wednesday.

The approval came from the Drugs Controller General of India (DCGI), according to the source.

AstraZeneca has resumed British clinical trials of the vaccine, one of the most advanced in development for COVID-19, after they were paused earlier this month following a serious side effect in a trial participant.

Trials have also resumed in Brazil and South Africa, but remain on hold in the United States.

Indian regulators had allowed Serum’s trials of the AstraZeneca vaccine to resume under certain conditions, including increased safety monitoring and informing volunteers about new findings, a DCGI source said.

“We allowed them (to resume trials) after a detailed discussion with authorities in the UK and the company itself,” the source added.

Serum, the world’s biggest vaccine manufacturer, did not respond to Reuters requests for comment, while DCGI representatives did not respond to emails seeking comment.