An expert panel of India's central drug authority has recommended permission for conducting a phase-3 clinical trial of Covid vaccine Covovax as a booster dose in adults, official sources said on Sunday.

The Drugs Controller General Of India (DCGI) has already approved Covovax for restricted use in emergency situations in adults on December 28.

It is yet to be included in the country's inoculation programme.

The Subject Expert Committee on Covid-19 of the Central Drugs Standard Control Organisation had on Friday recommended giving permission for conducting a phase-3 clinical trial of the single-dose Covid-19 vaccine Sputnik Light as a booster dose.

In February, Director, Government and Regulatory Affairs at Serum Institute of India, Prakash Kumar Singh had sought from DCGI nod to conduct a phase-3, observer-blind, randomized, controlled study to evaluate the safety and immunogenicity of Covovax as a booster dose in adults who were vaccinated with Covishield or Covaxin at least 3 months ago, an official source had said.

Singh had stated many countries have already started 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 early availability of Covovax for booster dose use for people of our country as well as the world at large in line with our prime minister's vision of 'Making in India for the World'.

"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 kindly grant us permission to conduct a phase-3 clinical trial for booster dose of Covovax in Indian adults," Singh is learnt to have stated in the application.

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

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