Amidst an ongoing surge in dengue cases across Bangladesh, a promising dengue vaccine candidate, TV005, faces significant hurdles as Phase III clinical trials stall due to a critical lack of funding. The tetravalent vaccine, which has demonstrated effectiveness against all four dengue serotypes, including the currently dominant DEN-2 strain, is already undergoing Phase III trials in India and Brazil.
Vaccine Development and Trial Status
The TV005 vaccine, developed by the US National Institutes of Health (NIH) and evaluated by the University of Vermont Vaccine Training Centre since 2009, has shown favorable results in Phase II clinical trials conducted in Bangladesh. These trials were led by the International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b) in collaboration with the Larner College of Medicine at the University of Vermont. The results from Phase II trials were recently published in The Lancet Infectious Diseases. Despite these promising outcomes, the crucial Phase III trial, necessary for regulatory approval and widespread availability, remains unfunded in Bangladesh.
Funding Challenges and Potential Delays
Discussions are reportedly ongoing with India's Panacea Biotech to secure funding for the trials in Bangladesh; however, a senior icddr,b official indicated that Panacea has shown little interest in financing the Phase III trials locally. This funding shortfall could delay the vaccine's availability in Bangladesh by three to five years. "Without adequate funding, the trial remains stalled," the official stated, requesting anonymity.
Dengue Serotype Prevalence and Patient Trends
Recent data from the Institute of Epidemiology, Disease Control and Research (IEDCR) indicates that the DEN-2 serotype has been the predominant strain in Bangladesh, accounting for approximately 69% of dengue cases between July and September 2024. Virologist Dr. Abdullah Omar Nasif from IEDCR noted that while the dominance of DEN-2 may reduce the risk of widespread reinfection among previously affected populations, it still poses a threat, particularly outside Dhaka where many have yet to develop immunity. The DNCC Dedicated Covid-19 Hospital, now repurposed as a dengue treatment center, reported managing 692 patients as of September 28, compared to 2,482 in the same month last year. According to AKM Johirul Hossain Khan, the hospital's acting director, most patients exhibit common dengue symptoms, such as low platelet counts, bleeding, and weakness, but those without complications are recovering well.
