India's first dengue vaccine inches closer to reality - trial enrolment to end by THIS date

India is inching closer to its first indigenous dengue vaccine, with phase-3 clinical trial enrolment expected to be completed by October 2025. Around 10,500 participants are being enrolled across 20 centres, with 8,000 already receiving either the vaccine or a placebo, according to scientists from the Indian Council of Medical Research (ICMR).

The one-shot vaccine, developed by Panacea Biotec and branded as DengiAll, is being tested through a multi-centre, double-blind, randomised, placebo-controlled trial. The trial is co-led by ICMR-National Institute of Translational Virology and AIDS Research in Pune, National Institute of Epidemiology (NIE) in Chennai, and the National Institute of Virology, Pune.

"There have been no safety concerns in the Phase-1/2 results for this one-shot vaccine," said NIE Director Dr Manoj Murhekar. "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." 

The phase-3 trial was launched in August 2023, with the first participant dosed at PGIMS Rohtak. Achieving efficacy across all four dengue virus serotypes remains a challenge. "The dengue virus has four serotypes, 1 to 4, with low cross-protection. That means individuals can be infected multiple times," Dr Murhekar said. "In India, all four serotypes are known to circulate or co-circulate in many regions."

Currently, there is no licensed vaccine or antiviral treatment for dengue in India. The Union Health Ministry earlier said the TV003/TV005 vaccine strain, originally developed by the NIH in the US, has shown promising results in Brazil. Among the three Indian companies granted access to the strain, Panacea Biotec is at the most advanced stage. It has developed a full-fledged formulation and holds a process patent for the vaccine.

"Dengue is a major public health concern," said Dr Murhekar, pointing to India's high case load. WHO data show that over 129 countries had reported dengue by the end of 2023. In India, about 75–80% of infections are asymptomatic, but carriers can still transmit the virus. Symptomatic infections — seen in roughly 20–25% of cases — are especially dangerous for children, who face a higher risk of hospitalisation and death. In adults, severe complications can include dengue hemorrhagic fever and dengue shock syndrome.

According to official data, India recorded 2.3 lakh dengue cases and 297 deaths in 2024. As of March 2025, over 12,000 new cases had already been reported. 

Dr Murhekar noted that "the two-year follow-up period will be critical in understanding the vaccine’s long-term impact, safety, and ability to protect against all four serotypes."

(With inputs from PTI)