The letter was written by Prakash Kumar Singh, Director, Serum Institute of India (SII) on March 27, they said.?Last month, Covid-19 Working Group headed by Dr N K Arora had also recommended to the health ministry inclusion of Covovax on the CoWIN portal as a heterologous booster dose for adults who have been vaccinated with two doses of either Covishield or Covaxin.

The Drugs Controller General of India (DCGI) had on January 16 approved the market authorisation for Covovax for those who have been administered two doses of either Covishield or Covaxin. Also, Covovax has been approved by the World Health Organisation (WHO) and the US Food and Drug Administration (USFDA).

The DCGI had approved Covovax for restricted use in emergency situations in adults on December 28, 2021, in the 12-17 age group on March 9, 2022, and in the 7-11 age group on June 28, 2022, subject to certain conditions.

Covovax is manufactured through technology transfer from US-based vaccine maker Novavax. It has been approved by the European Medicines Agency for conditional marketing authorisation. It was granted emergency-use listing by WHO on December 17, 2021.

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