Dengue
- It is a mosquito-borne flavi virus (Dengue viruses 1-4 sero types) disease
- Area affected: tropical and subtropical.
- No specific therapy.
- Prevention: Vaccination, Mosquito control
Aedes aegypti – A mosquito that spreads dengue fever
Status of vaccine development
- Brand name: Dengvaxia (CYD-TDV) by Sanofi Pasteur.
- First registered in Mexico in December, 2015.
- World’s first immunization against the mosquito-borne virus.
- Type: Live recombinant tetravalent vaccine.
- Dose: 0/6/12 months.
- Useful for: 9-45 years of age living in endemic areas.
- Status: Reviewing by the WHO Strategic Advisory Group of Experts (SAGE) on Immunization.
- Challenges to vaccine development
- Infection by one of the four dengue virus serotypes has been shown to confer lasting protection against homotypic re-infection, but only transient protection against a secondary heterotypic infection. Moreover, secondary heterotypic infection is associated with an increased risk of severe disease. This and other observations suggest an immunopathological component in dengue pathogenesis, which is referred to as immune enhancement of disease. Due to these dengue-specific complexities, vaccine development focuses on the generation of a tetravalent vaccine aimed at providing long-term protection against all virus serotypes. Additional challenges are posed by the lack of an adequate animal disease model and the resulting uncertainty around correlates of protection. In spite of these challenges, vaccine development has made remarkable progress in recent years, and the current dengue vaccine pipeline is advanced, diverse and overall promising.
(Source: WHO)
