THE DENGUE VACCINE PIPELINE: A RELIEF OR A CONCERN FOR THE FUTURE?-A REVIEW

Dengue is a prevalent arboviral disease caused by any of the dengue virus serotypes (DENV 1-4). These virus types are closely related, and the dengue virus infection is a crucial economic and public health burden in endemic areas. The multifaceted epidemiology of DENV and prevalent infections affecting around 390 million people every year, show a diversity of clinical manifestations, from asymptomatic illness to fatal DHF and DSS, thereby making vaccine development imperative. Several vaccines for DENV infection are in the pipeline or in various evaluation phases, with three vaccine candidates—Dengvaxia®, TV003, and TAK-003—showing encouraging results. Dengvaxia proved inefficient in generating a stabilised immune reaction to all the serotypes (1–4) of dengue virus due to the development of ADE in dengue-naïve individuals. Hence, a better vaccine was imperative irrespective of the previous dengue exposure and age. Several DENV vaccines have been formulated based on numerous strategies: live attenuated/inactivated viruses, genetically engineered viruses, DNA, recombinant proteins, mRNA, etc. They are under various phases of trials or preclinical examination. However, due to the complex pathogenesis of the disease, developing such vaccines to be effective against all serotypes in individuals of all age groups requires time. This review article encompasses several aspects of the existing DENV vaccines; licenced and under trial, ranging from molecular design, efficacy, and adverse effects to the immunogenicity of each vaccine platform. Safety-related issues in DENV vaccine progress and future developments in DENV vaccines along with research gaps in the current development are also discussed.