PUNE, July 23 -- The Phase 3 clinical trial for India's first dengue vaccine has enrolled over 7,248 participants since its launch in August 2024, marking a major milestone in the development of an indigenous dengue vaccine. The trial, led by the Indian Council of Medical Research (ICMR) in collaboration with Panacea Biotec, is testing DengiAll, a tetravalent vaccine designed to protect against all four known dengue virus serotypes. The vaccine strain (TV003/TV005), originally developed by the US National Institutes of Health (NIH), has shown promising results in global studies. The NIH later sub-licensed the technology to several firms globally including Indian companies like Panacea Biotec and Indian Immunologicals. Among the Indian licensees, Panacea Biotec is the most advanced, having completed Phase 1 and 2 trials in 2018-19. The company has since developed a full vaccine formulation and holds a process patent. The ongoing multi-centre, double-blind, randomized, placebo-controlled Phase 3 trial began on August 14, 2024, and aims to recruit 10,355 healthy volunteers aged 18-60 years across 19 clinical sites in India. The trial has received all regulatory approvals from the Drug Controller General of India (DCGI). Enrolment is expected to conclude by October 2025, with each participant to be monitored for two years. Data will be submitted to the Central Drugs Standard Control Organisation (CDSCO) for review. "This is the first-ever Phase 3 dengue vaccine trial in India," said Dr Shrikant Tripathi, Research Head at Dr DY Patil Vidyapeeth, Pune, one of the trial sites. "It is primarily funded by ICMR, with some support from Panacea Biotec-no external funding is involved. This trial reflects India's push toward vaccine self-reliance." Dr Rajesh Karyakarte, Head of Microbiology department, at B J Medical College, Pune, one of the Sentinel Surveillance Institute for National Centre for Vector Borne Disease Control, told HT, "India is contributing nearly a third of global dengue cases. Dengue cases and minor to major outbreak are now being reported round the year. The climate change, monsoon pattern and humidity are further fuelling expansion and transmission of the vector borne disease. In India, out of the four Dengue serotypes, the DENV-2 serotype strongly associated with severe manifestations such as dengue haemorrhagic fever and dengue shock syndrome is prominent in circulation. A safe and effective dengue vaccine is no longer optional but essential to protect the community to reduce hospital burden and prevent repeat infections that can be fatal," he said. According to Panacea Biotec, there is no fixed timeline for the efficacy endpoint-it depends on dengue transmission and infection rates. DengiAll activates immune responses against all four dengue virus strains. "Once efficacy is established and approved by authorities, the vaccine can be included in national immunisation programmes. Currently, there is no dengue vaccine in India's routine immunisation schedule for children or adults," said a source from Panacea Biotec. Dr Sheela Godbole, Director of ICMR's National Institute of Translational Virology, is the national principal investigator for the trial. An email query sent to ICMR, ICMR-NITVAR, and national principal investigator Dr Sheela Godbole remained unanswered. Meanwhile, the Serum Institute of India (SII) too is preparing to roll out Phase 3 trials for its own dengue vaccine Dengusiil, for which Phase 1 and 2 trials in adults and children have been successful. The Phase 3 study will cover about 10,000 children aged two to under 18 years across multiple sites in India, considering regional dengue epidemiology. The trial is expected to begin by the end of 2025, with follow-up for at least three years and an overall duration of four to five years for the vaccine to be rolled out in the market. Dengusiil, like DengiAll, is a live attenuated tetravalent vaccine that generates neutralising antibodies against all four dengue serotypes. Earlier trials demonstrated safety and high immunogenicity in both adults and children, with no serious adverse events reported. SII and ICMR have signed an MoU for the upcoming study. Once protocol approvals are in place, study site details will be finalised and submitted to CDSCO....