Functional antibody responses and protection against symptomatic dengue.

Exposure to dengue virus (DENV) triggers the development of anti-viral antibodies that may contribute to either protection or disease progression. Antibodies exist in different isotypes and subtypes, with diverse specificities and functions. IgG antibodies are produced during primary and secondary DENV infections, where they play a role central role in mediating protective immunity, and may also contribute to antibody-dependent enhancement in a secondary heterotypic infection. Although IgG antibodies are widely recognised as key mediators of protective immune responses during DENV infection, antibody specificities, types and functions that reliably correlate with protection remain unclear. A better understanding of anti-DENV antibodies and their roles in protection against symptomatic dengue is essential especially in guiding the design of dengue vaccines. In this review, antibody functions and effector mechanisms in DENV infection are discussed, with a focus on naturally acquired immunity and neutralising antibody responses following vaccination. In addition, current knowledge gaps in antibody functions during DENV infection will be highlighted.