Sanofi and GlaxoSmithKline (GSK ) have secured the approval to conduct a Phase III clinical trial of their adjuvanted recombinant-protein Covid-19 vaccine candidate in India.

The global, randomised, double-blind trial will evaluate the vaccine’s safety, efficacy and immunogenicity in more than 35,000 subjects aged 18 years and above.

Participants will be enrolled at trial centres across the US, Asia, Africa and Latin America.

Sanofi noted that subjects may choose to take an approved Covid-19 vaccine during the Phase III trial.

According to the trial design, all subjects, including those in the control arm, will be provided with an option to receive the study vaccine soon after its safety and effectiveness are established.

Sanofi Pasteur India country head Annapurna Das said: “India is participating in Sanofi Pasteur’s pivotal Phase III study, and subject to subsequent approvals, we should soon begin enrolment of study participants in the country.

“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.”

The two-stage Phase III trial will first assess the efficacy of a vaccine formulation that targets the original virus strain (D.614). The second stage will test another formulation that targets the Beta variant (B.1.351).

Based on recent scientific data, antibodies generated against the Beta variant could offer wide cross-protection against other variants which are more transmissible.

The trial’s design will allow testing of the vaccine’s effectiveness against multiple circulating variants.

Preventing symptomatic Covid-19 in SARS-CoV-2 naïve adults is the primary goal while secondary endpoints are the prevention of severe Covid-19 and asymptomatic disease.

Furthermore, the companies will conduct studies to analyse their adjuvanted recombinant-protein Covid-19 vaccine to create a strong booster response, irrespective of the initial vaccine administered.

Interim data from a global Phase II trial revealed that the vaccine candidate led to high neutralising antibody response rates across all adult age groups.