Zika virus (ZIKV) can be passed from a pregnant woman to her fetus. Infection during pregnancy can cause microcephaly and other severe birth defects. Currently, there are no vaccines to prevent or medications to treat Zika infections.

CDC engineered chimeric Zika viruses on the dengue virus (DENV) sub-type 2 (D2) PDK-53 vaccine backbone (D2 PDK-53) for potential development of a live-attenuated Zika vaccine. These chimeric viruses could also be used for other research purposes such as development of diagnostic tests. The cDNA genetic clones for the chimeric constructs have been successfully engineered, and scientists in the laboratory are in the process of deriving infectious chimeric D2 PDK-53/Zika viruses.