Dengue is a mosquito-borne disease caused by an infection from one of its viruses DENV 1 – 4. It causes morbidity and mortality in people with various age groups. The ability of mosquitoes to survive and multiply in tropical and subtropical regions results in this disease which has become endemic in many regions across the globe.
Sanofi launched first Dengue Vaccine (Dengvaxia) in Mexico in 2015. It came at a cost of severe dengue infectivity in children, with no prior history of Dengue, after getting vaccinated. Certain scientific rationale had been stated since the adverse effects of Dengvaxia were observed after the third year post its administration in children. Currently, this vaccine is available for children aged 6 – 16 with prior history of Dengue, thus to suppress any future infectivity by Dengue virus.
Modern scientific know-how has helped synthesize tetravalent vaccine by Takeda (Japanese Company) which has shown no side-effects in spite of baseline dengue immune status in children aged 4 and above. The vaccine is already approved for use in European, South American and some South Asian nations. However, just this month US FDA issued further queries to Takeda regarding its dengue vaccine’s clinical data thereby prohibiting its use in its parameter.
More recently, Instituto Butanta in collaboration with the NIH and Merck (MSD), has conducted Phase III trials to study the efficacy of dengue vaccine in about 16000 volunteers. The agency found success with its vaccine to some degree but a perfect vaccine to cure dengue is not on the immediate horizon.
To add onto this ambitious list, India will likely hold its Phase III trials starting August 2023 for two of the dengue vaccines designed by Serum Institute of India and Pancea Biotech, respectively in collaboration with the Indian Council of Medical Research (ICMR).
To prevent Dengue, one may as well think about mosquito control strategies by designing smart repellents. Since not all Aedes Aegypti mosquito contains same DENV virus, suggesting variable genetic makeup, a possible smart-repellent targeting all the genetically-different Aedes Aegypti mosquitoes might lead to better dengue control.
Please refer the article by Ooi et al to know more on the vaccination strategies adopted for tackling dengue immunity.
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