The Serum Institute of India on Friday said it has begun production of the first batch of Covovax, a coronavirus vaccine developed by biotechnology company Novavax. The vaccine showed an overall efficacy of 90.4% in phase three trials.

“A new milestone has been reached; this week we began our first batch of Covovax [a COVID-19 vaccine developed by Novavax] at our facility, here in Pune: Serum Institute India,” the company said on Twitter.

Adar Poonawalla, the chief executive officer of Serum Institute, congratulated the team. “Excited to witness the first batch of Covovax (developed by @Novavax) being manufactured this week at our facility in Pune,” tweeted Poonawalla. “The vaccine has great potential to protect our future generations below the age of 18. Trials are ongoing. Well done team @seruminstindia! (sic).”

India is yet to approve a coronavirus vaccine for children. India, which launched its vaccination drive on January 16, has been inoculating its population with three Covid-19 vaccines. One is Serum Institute’s Covishield, developed in collaboration with the Oxford University and drug company AstraZeneca. Another is Covaxin, created in partnership of Indian drug company Bharat Biotech and the Union government’s Indian Council of Medical Research. The third is Russia’s Sputnik V.

On January 30, Poonawalla had announced that his company had applied to begin trials in India. Poonawalla had then said that he was expecting to launch Covovax in June. However, later, he said the launch is likely to happen in September, according to News18.

The Serum Institute of India in Pune is the world’s largest vaccine manufacturer. In July 2020, Novavax had signed a deal with the Serum Institute to produce 2 billion (200 crore) doses of coronavirus vaccines. Poonawalla had then said that his company would manufacture the Novavax vaccine “upwards of 40-50 million [4-5 crore] doses per month” from around April this year.

As India opened up its vaccination programme to the entire adult population from May, it began to face hurdles due to lack of sufficient stock for everyone above 18 years. Following this, the Narendra Modi government announced a change in its vaccination policy on June 7.