Serum Institute of India (SII) has sought permission from India's drug regulator to conduct a phase-3 study of its COVID-19 vaccine Covovax as a booster dose in adults, official sources said on Sunday.

The Drugs Controller General Of India (DCGI) had approved Covovax for restricted use in emergency situations in adults on December 28. The vaccine is yet to be included in the country's inoculation programme.

Prakash Kumar Singh, Director, Government and Regulatory Affairs at SII had last week submitted an application to DCGI seeking nod for phase-3, observer-blind, randomised, controlled study to evaluate the safety and immunogenicity of Covovax as booster dose on those who have received primary vaccination either with Covishield or Covaxin at least three months ago, an official source said.

Singh has stated that many countries are already administering booster doses to their citizens considering the uncertainties of the COVID-19 pandemic.

"We are sure that your approval for conducting this clinical trial will ensure an early availability of Covovax for booster dose use for people of our country as well as the world in line with our prime minister's vision of 'Making in India for the World'," Singh is learnt to have stated in the application.

"Our firm is committed to providing world-class life-saving vaccines at an affordable price under the visionary leadership of our CEO Adar C Poonawalla. We request you to grant us permission to conduct a phase-3 clinical trial for booster dose of Covovax in Indian adults."

Covovax is manufactured by technology transfer from Novavax and is approved by the European Medicines Agency for conditional marketing authorisation and also granted emergency use listing by WHO.

In August 2020, the US-based vaccine maker Novavax had announced a licence agreement with SII for the development and commercialisation of NVX-CoV2373, its COVID-19 vaccine candidate, in low and middle-income countries and India.

(PTI)