The Drugs Controller General of India (DCGI) has granted approval to Sanofi and Glaxo Smith Kline (GSK) to conduct phase-III clinical study, to assess the safety, efficacy and immunogenicity of their adjuvanted recombinant-protein Covid-19 vaccine candidate in India, the pharma giants announced on Thursday.

The global, randomised, double-blind Phase-III study will include more than 35,000 volunteers aged 18 and older across sites in the US, Asia, Africa, and Latin America as well as from India.

The trial aims to prevent symptomatic Covid-19 infections, as well as reduce severe disease and asymptomatic infection.

“India is participating in Sanofi Pasteur’s pivotal Phase-III study, and subject to subsequent approvals, we should soon begin enrollment of study participants in the country,” said Annapurna Das, Country Head, Sanofi Pasteur India, in a statement.

“As the virus continues to evolve, we are anticipating what will be needed in the coming months and years, and accordingly, have adapted our vaccine development programme. We believe our Covid-19 adjuvanted, recombinant vaccine can make a significant contribution to the ongoing fight against Covid-19 and are committed to initiating our clinical programme in India, at the earliest” she added.

As vaccination becomes available, study participants are encouraged to receive an approved Covid vaccine during the study, if they wish to do so. As part of the study design, all participants including the control group will be offered the study vaccine as soon as it is determined to be safe and effective.

In a two-stage approach, the study will initially investigate the efficacy of a vaccine formulation targeting the original virus strain (D614), while a second stage will evaluate a second formulation targeting the Beta variant (B1351).

Recent scientific evidence shows that antibodies created against the Beta variant may provide broad cross-protection against other more transmissible variants.

Sanofi and GSK will also run clinical studies to assess the ability of the adjuvanted recombinant-protein Covid-19 vaccine candidate to generate a strong booster response regardless of the type of vaccine initially received.

The Phase 3 study initiation follows the global interim Phase 2 results which showed that the adjuvanted recombinant Covid-19 vaccine candidate achieved high rates of neutralising antibody responses in all adult age groups.

The Phase-II trial, which involved 722 adult volunteers from the US and Honduras between 18 to 95 years old, did not raise any safety concerns and also produced a strong immune response across all age groups.

It showed 95 per cent to 100 per cent seroconversion following a second injection, while a single jab produced high neutralising antibody levels among people with prior SARS-CoV-2 infection. This suggested the vaccine’s strong potential for development as a booster shot.

The French pharma company Sanofi and its British peer GSK aim to produce up to one billion doses in 2021.