Zika virus (ZIKV) is a flavivirus primarily transmitted by infected Aedes mosquitoes. Infection with ZIKV during pregnancy can affect the fetus causing microcephaly, neurological complications, and other birth defects. Adults are also at a heightened risk of developing Guillain-Barre syndrome and other neurological disorders. In response to the 2015-2016 Zika outbreak, CDC scientists developed a recombinant vaccine candidate as well as reagents and methods to detect ZIKV infection. The recombinant vaccine candidate utilizes adenovirus vector expressed viral envelope proteins. This vector-based vaccine candidate is an efficient platform that elicits a strong response in mouse models; added vaccine testing in rabbit models is underway. Virus-like particles generated from the vector are also being used for ZIKV diagnostics. The US Food and Drug Administration (FDA) has issued an Emergency Use Authorization (EUA) for CDC's Zika IgM antibody capture enzyme-linked immunosorbent assay (Zika MAC-ELISA) that utilizes VLP technology for in vitro qualitative detection of human IgM antibodies to Zika virus in serum. It can also be used to test cerebrospinal fluid (CSF) when submitted with a patient-matched serum sample. The CDC Zika MAC-ELISA assay is currently in use at qualified laboratories designated by CDC.