Moving a step closer to developing India’s first vaccine against dengue, drug-makers Serum Institute of India and Panacea Biotec have submitted their responses to the call by the Indian Council of Medical Research (ICMR) for an Expression of Interest for collaborative Phase 3 clinical trials for indigenous manufacturers.

The Phase 3 trial is being done for evaluation of efficacy, along with safety and immunogenicity of tetravalent dengue vaccine candidate developed by Indian manufacturers. Trials could start close to August for the adult vaccine, a senior health official said.

The ICMR says the dengue viral disease causes significant morbidity and mortality across the globe and in India, 2 to 2.5 lakh cases are reported annually.

The global incidence of dengue has grown dramatically with about half the world’s population now at risk. Though an estimated 100-400 million infections occur each year, over 80% are generally mild and asymptomatic. Hence, in 2019, the World Health Organization (WHO) identified dengue to be one among the top 10 global health threats.

As of now, there is no specific treatment for dengue/severe dengue. “Therefore, there is an urgent need to develop effective vaccines against dengue viral disease,” the ICMR said.

Giving details about the two potential vaccines, Nivedita Gupta, Head of Virology, ICMR, said that the Serum Institute of India’s vaccine initiated one/two studies in paediatric population and the plan for Panacea’s vaccine is to conduct Phase 3 randomised, double-blind, placebo-controlled trial in 10,335 healthy adults (aged 18-80) in 20 sites (ICMR-funded).

She added that the Phase 3 protocol has been approved by the Drugs Controller General of India (January 2023) and the company is trying to upscale vaccine production with the trials expected to start in August-September.

The ICMR has noted that the desirable characteristics of a dengue vaccine includes acceptable short- and long-term safety profile (no antibody-dependent enhancement), inducing protection against all four serotypes of dengue, reducing risk of severe diseases and deaths, inducing a sustained immune response and effectiveness irrespective of the earlier sero-status and age of the individual.