Of this, 15 states and union territories have only given Covishield, being manufactured by the Pune-based Serum Instiute of India. The other vaccine being administered in India is the indigenous Covaxin from Bharat Biotech in Hyderabad. Giving details, of the 127,605,870 COVID-19 vaccination jabs administered till now, 11,60,65,107 are of Covishield while 1,15,40,763 are of Covaxin, according to the government's CO-WIN portal.

Moreover, about 15 states and union territories, including Goa, Chandigarh and Jammu and Kashmir, have administered only Covishield to its beneficiaries.

Experts said Covishield is being produced at a much higher scale than Covaxin due to which its availability is more.

Dr Samiran Panda, the Head of Epidemiology and Communicable Diseases at the Indian Council of Medical Research, said soon the production of Covaxin will be ramped up.

''Following which, the vaccine production capacity will increase significantly,'' he said. Bharat Biotech on Tuesday said capacity expansion has been implemented across multiple facilities in Hyderabad and Bangalore, to reach approximately 700 million doses per year.

The Department of Biotechnology is also providing financial support as grants to vaccine manufacturing facilities for enhanced production capacities. ''The current production capacity of indigenously developed Covaxin vaccine will be doubled by May-June 2021 and then increased nearly 6-7 fold by July-August 2021 i.e increasing the production from 10 million vaccine doses in April, 2021 to 60-70 million vaccine dose per month in July-August,'' said the ministry of science and technology in a statement on Monday.

India granted emergency use authorisation to Covaxin and Covishield, following which the vaccination drive started in the country on January 16. Prime Minister Narendra Modi and External Affairs Minister S Jaishankar were among those administered Bharat Biotech's Covaxin.