CDC; Frederick Murphy, Cynthia Goldsmith

Scientists at Florida Gulf Coast University and their colleagues have found that human cells were more likely to be infected with Zika virus in vitro if they contained antibodies to dengue virus. Their findings, detailed Monday (April 25) in a bioRxiv preprint, could help explain why Zika infection appears to be more severe in areas where dengue is endemic, and points to a potential unintended effect of dengue vaccination.

Antibodies to dengue can increase the virus’s infectivity for certain types of immune cells through a process called antibody-dependent enhancement (ADE), resulting in the production of more virus and more severe illness. (See “Antibody-Dependent Enhanced (ADE) Immunity,” The Scientist, May 2013.) For the present study, the researchers cultured cells with immune proteins called Fc receptors and exposed them to Zika virus in the presence of human monoclonal antibodies to dengue,...