India’s drug regulatory agency is set to review applications for the emergency use authorisation of one homegrown and two foreign-made Covid-19 vaccines which, if approved, would enable the government to roll out its planned immunisation campaign within weeks.

The Hyderabad-based Bharat Biotech on Monday filed an EUA application with the Central Drugs Standard Control Organisation, the third such submission to the regulator after EUA applications from Pfizer and the Pune-based Serum Institute of India.

The Serum Institute is manufacturing the AstraZeneca vaccine in India.

The Pfizer vaccine has shown 95 per cent efficacy in protecting people from Covid-19 in clinical trials in the US and other countries, while the AstraZeneca vaccine has shown 62 per cent efficacy in one dosing regimen and 90 per cent efficacy in another in the UK and Brazil. Bharat’s vaccine is currently under assessment for efficacy through a nationwide clinical trial involving 26,000 volunteers.

Health officials said each vaccine would be assessed through accelerated reviews to determine they qualify for EUA, a process that allows the CDSCO to waive certain regulatory requirements to make available critical drugs or vaccines during health emergencies.

The EUA reviews for the three vaccines would rely on different sets of clinical trial data. Pfizer has submitted clinical trial data from other countries, while the Serum Institute will combine foreign and Indian clinical trial data, and Bharat’s data was generated within India.

The Union health ministry has indicated that the Covid-19 immunization campaign would initially seek to vaccinate around 10 million healthcare staff and 20 million frontline workers with high occupational vulnerability to Covid-19.

The goal would be to vaccinate in the coming months 250 million to 300 million people from high-priority groups vulnerable to the infection or severe disease, said an official guiding India’s Covid-19 vaccination strategy.

India will need 500 million to 600 million doses of vaccines for the planned campaign.

The Serum Institute has said it can produce around 70 million doses per month, which can be stretched to 100 million doses a month, with half of it available for domestic use and the rest intended for the global market. Pfizer has not made public how many doses it can supply India with.

Serum’s chief executive officer, Adar Poonawalla, has told the UK-based Financial Times that the vaccine will be available for purchase in India by March or April. He was quoted by the newspaper as saying that Serum would initially supply the Indian government and then expected to sell 20 to 30 million doses to private facilities.

But a government official involved in the Covid-19 vaccination strategy told The Telegraph on Monday that there was “no decision” yet on private market sales of Covid-19 vaccines.