Serum Institute of India (SII) CEO Adar Poonawalla on Saturday said clinical trials of COVID-19 vaccine Covovax have begun in India and the company hopes to launch it by September this year.

In August 2020, US-based vaccine maker Novavax, Inc 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.

"Covovax trials finally begin in India; the vaccine is made through a partnership with @Novavax and @SerumInstIndia. It has been tested against African and UK variants of #COVID19 and has an overall efficacy of 89%. Hope to launch by September 2021!," Poonawalla said in a tweet.

The development and commercialisation pact between Novavax and SII excludes major upper-middle and high-income countries, for which Novavax continues to retain rights.

In January this year, Poonawalla had said SII expected to launch Covovax by June 2021.

"Our partnership for a COVID-19 vaccine with @Novavax has also published excellent efficacy results. We have also applied to start trials in India. Hope to launch #COVOVAX by June 2021!", Poonawalla had said in a tweet.

SII is already supplying AstraZeneca/Oxford COVID-19 vaccine, Covishield, in India and to other countries across the world.