The two doses are given four weeks apart. The vaccine can be stored at 2C to 8C.
The vaccine has an efficacy rate of 81%, preliminary data from its phase 3 trial shows.
India's regulators gave the vaccine an emergency approval in January while the third phase of the trial was still underway, sparking scepticism and questions from experts.
Bharat Biotech says it has a stockpile of 20 million doses of Covaxin, and is aiming to make 700 million doses out of its four facilities in two cities by the end of the year.
What was the controversy around Covaxin?
It all began when the regulator in January said the vaccine had been approved for "restricted use in emergency situations in public interest as an abundant precaution, in clinical trial mode, especially in the context of infection by mutant strains".
Experts wondered how a vaccine was cleared for emergency use by millions of vulnerable people when its trials were still underway. The All India Drug Action Network at the time said that it was "baffled to understand the scientific logic" to approve "an incompletely studied vaccine". It said that there were "intense concerns arising from the absence of the efficacy data".
Both the manufacturer and drug regulator had defended Covaxin, saying it was "safe and provides a robust immune response".
Bharat Biotech had said that Indian clinical trial laws allowed "accelerated" authorisation for use of drugs after the second phase of trials for "unmet medical needs of serious and life-threatening diseases in the country". It had promised to provide efficacy data for the vaccine by February, which it has now done.
What about Covishield?
pgThe Oxford-AstraZeneca vaccine is being manufactured locally by the Serum Institute of India, the world's largest vaccine manufacturer. It says it is producing more than 60 million doses a month.
The vaccine is made from a weakened version of a common cold virus (known as an adenovirus) from chimpanzees. It has been modified to look more like coronavirus - although it can't cause illness.