Bharat Biotech International Limited (BBIL), which developed India’s first potential indigenous coronavirus disease (Covid-19) vaccine, has said the first phase of testing has begun on 375 people, according to a report on Saturday.

Hindustan, HT’s sister publication, reported that Bharat Biotech has said that human trials of Covaxin started on July 15. The Hyderabad-based pharmaceutical company has jointly developed the vaccine with the Indian Council of Medical Research (ICMR) and National Institute of Virology (NIV).

Twelve hospitals in different parts of the country are carrying out this test.

The vaccine manufacturer has said that these are randomised double-blind clinical trials, Hindustan reported. Some of the people who have volunteered will be vaccinated and some will be given a placebo.

However, neither the volunteers nor the researcher knows who has been given the vaccine. They come to know who was injected with the vaccine only after the test period is over.

During the first phase of the trial, it is checked whether the people who have been vaccinated develop any adverse effect in their body.

Whether the vaccine works against the coronavirus disease will not be known at this stage, which is assessed in the second stage.

The hospitals where the vaccine trials have started include All India Institute of Medical Sciences (AIIMS) Delhi, AIIMS Patna, King George Hospital in Visakhapatnam, Post Graduate Institute of Medical Sciences (PGIMS) in Rohtak, Jeevan Rekha Hospital in Belgaum, Gillurkar Multispeciality Hospital in Nagpur, Rana Hospital in Gorakhpur, SRM Hospital in Chennai, Nizam Institute of Medical Sciences in Hyderabad, Kalinga Hospital in Bhubaneswar, Prakhar Hospital in Kanpur and a hospital in Goa.

ICMR had written to 12 institutes where human trials are to be held for the vaccine, Covaxin, ordering them to secure necessary approvals from internal committees and recruit people for clinical tests by July 7.

Bharat Biotech is among the seven Indian firms working on Covid-19 vaccines. It was the first to get the regulatory nod to begin phase 1 and phase 2 human trials to test the vaccine for efficacy and safety.