India's dengue vaccine Phase-3 trial enrolment to be completed by Oct: ICMR

Enrolment of about 10,500 participants in the phase III clinical trial of the indigenous one-shot Panacea Biotec developed dengue vaccine, DengiAll, is likely to be completed by October across 20 centres in India, according to ICMR scientists.

So far, 8,000 participants in various centres at Pune, Chennai, Kolkata, Delhi and Bhubaneswar among others have received either the vaccine or a placebo as part of the trial sponsored by the Indian Council of Medical Research (ICMR) and Panacea Biotec.

The trial is co-led by ICMR-National Institute of Translational Virology and AIDS research in Pune, National Institute of Epidemiology (NIE), Chennai and National Institute of Virology, Pune. 

Currently, there is no antiviral treatment or licensed vaccine against dengue in India.

The results of the Phase-1/2 trial has shown no safety concerns for the one-shot vaccine, NIE Director Dr Manoj Murhekar said.

"The participants enrolled in the Phase- III trial will be followed up for two-years. This trial will evaluate the efficacy of this tetravalent dengue vaccine," Dr Murhekar said.

The multi-centre, double-blind, randomised, placebo-controlled phase-III trial was launched in August last year to evaluate the jab's efficacy, safety and, long-term immunogenicity.

The first participant in this trial was vaccinated at the Pandit Bhagwat Dayal Sharma Post Graduate Institute of Medical Sciences (PGIMS), Rohtak last year.

The development of an effective vaccine is complex due to the need to achieve good efficacy for all four serotypes. The dengue virus has four serotypes, 1-4, with low cross-protection against each other, meaning individuals can experience repeated infections, Dr Murhekar said.

In India, all four serotypes of dengue virus are known to circulate or co-circulate in many regions.

The Union Health Ministry in a statement earlier had said that the tetravalent dengue vaccine strain (TV003/TV005), originally developed by the National Institutes of Health (NIH), USA, has shown promising results in clinical trials in Brazil.

Panacea Biotec, one of three Indian companies to receive the strain, is at the most advanced stage of development. The company has worked extensively on these strains to develop a full-fledged vaccine formulation and holds a process patent for this work.

Dengue is a major public health concern in India, ranking among the top 30 countries with the highest incidence of the disease.

The global incidence of dengue has been steadily increasing over the past two decades, with more than 129 countries reporting dengue viral disease by the end of 2023, according to the World Health Organisation (WHO).

In India, approximately 75-80 per cent of infections are asymptomatic, yet these individuals can still transmit the infection through the bite of Aedes mosquitoes.

Among the 20-25 per cent of cases where symptoms are clinically apparent, children are at a significantly higher risk of hospitalisation and mortality. In adults, the disease can escalate into severe conditions like dengue hemorrhagic fever and dengue shock syndrome.

According to the government data, around 12,043 dengue cases were reported till March this year. In 2024, 2.3 lakh cases and 297 deaths had been recorded.