Bharat Biotech had said that it plans to cover 28,500 subjects in its Phase 3 trial.
Covaxin, the coronavirus vaccine being developed by Bharat Biotech in collaboration with the Indian Council of Medical Research (ICMR), has been cleared for the third phase of clinical trials.
The Hyderabad-based vaccine maker had applied to the Drugs Controller General of India (DCGI) on October 2, seeking its permission to conduct Phase 3 trials for its COVID-19 vaccine candidate.
The firm in its application said that the study would cover 28,500 subjects aged 18 years and above and would be conducted in 19 sites - including Delhi, Mumbai, Patna and Lucknow - across 10 states.
Besides, Bharat Biotech, an indigenously developed vaccine candidate by Zydus Cadila Ltd is also in Phase 2 of human clinical trials.
The Pune-based Serum Institute of India, which has partnered with AstraZeneca for manufacturing the Oxford COVID-19 vaccine candidate, is also conducting Phase 2 and 3 human clinical trials of the candidate in India.
In a report last month, Bharat Biotech had said that an animal study has shown its vaccine candidate has helped develop a strong immune response to the highly infectious coronavirus.
"To summarise, the vaccine candidate was found to generate robust immune responses. Thus, preventing infection and disease in the primates upon high amounts of exposure to live SARS-CoV-2 virus," Bharat Biotech posted on its website.
Though it was initially planned that Covaxin would be launched in the market by August 15, government officials later told a parliamentary standing committee that such a drug would not be possible till at least next year.
Globally, more than 100 vaccines are being developed and tested to try to stop the COVID-19 pandemic, which has killed hundreds of thousands and ravaged the global economy.
On Thursday, one of the volunteers part of the clinical trials of the University of Oxford's potential COVID-19 vaccine that is seen by many as the world's leading candidate died in Brazil but authorities said that the trial would continue.
Oxford confirmed the plan to keep testing, saying in a statement that after careful assessment "there have been no concerns about safety of the clinical trial."