Antibody-dependent enhancement in the immunopathogenesis of severe dengue, implications for the development and use of vaccines

Abstract

Dengue virus infection is the most important vector transmitted disease in tropical countries such as Colombia, where all the four dengue virus serotypes are circulating and are involved in successive secondary infections which induce severe or even fatal cases. The central key to understanding the severe dengue cases is the endothelial function damage which appears as plasma leakage, coagulation impairment, and organ compromise. Severe dengue could be explained by different theories, among them the antibody-dependent enhancement (ADE) phenomenon is the best known. This theory postulates that the second heterotypic virus causing a secondary infection is recognized by antibodies raised during the first infection but are ineffective to neutralize the virus. Instead this virus-antibody complex is internalized by Fc-gamma receptor-bearing cells increasing the viral replication and inducing an aberrant immune response that contributes to severe dengue presentation. This manuscript is aimed to review the evidence about the ADE phenomenon and its involvement in the severe evolution of dengue cases. Here, it will be described the extrinsic and intrinsic ADE concepts and how these phenomena must be considered to the design, development, and implementation of a dengue vaccine because the evidence indicates that ADE affects both efficacy and safety of vaccine prototypes.