Figure 2.

Antibody response and cross-reaction effect between DENV and ZIKV. Primary infection by one of the viruses can promote the production of long-lasting neutralizing antibodies the homologous virus and short-lived cross-reactive neutralizing antibodies, i.e., in the first few months (usually 3 months) after infection, neutralizing antibodies also neutralizes heterologous related viruses. However, after 3 few months, cross-neutralization is lost and cross-reactive non-neutralizing antibodies may enhance the infection during a secondary exposure by a heterologous related virus, for example, a second distinct DENV serotype, or a DENV infection following a primary ZIKV infection. Virus particles opsonized with non-neutralizing antibodies have facilitated access to permissive cells via FcγR which causes enhanced virus proliferation and increased viral load. This phenomenon is known as antibody-dependent enhancement (ADE). On the other hand, heterologous infections after short periods between the primary and secondary infections can induce virus neutralization by cross-reactive antibodies. Abbreviations: ADE—antibody-dependent enhancement. Images from Servier Medical Art, licensed under a Creative Common Attribution 3.0 Generic License (http://smart.servier.com/; accessed on 10 Februrary 2022).