Bharat Biotech has written to the India's drug regulator seeking extension of the shelf-life of its indigenously developed COVID-19 vaccine Covaxin from six to 24 months, sources said on Sunday.

Covaxin, along with Covishield manufactured by Serum Institute of India, are the two vaccines so far being used in India's current COVID-19 vaccination drive. Russian vaccine Sputnik-V has also been approved for emergency use in India.