Despite a limited number of available full-length Zika virus sequences, the molecular data are sufficient to reveal patterns of viral evolution and movement. The virus is likely to have originated in East Africa and subsequently spread to West Africa and then to Asia, resulting in distinct lineages (Nigerian Cluster, MR766 Cluster, and the Asian genotype).101,117 All strains currently associated with the outbreak in the Americas are of
the Asian genotype and are most closely related to strains from Yap, Cambodia, Thailand, and French Polynesia.118 The strains from the Americas that have been examined to date are genetically very similar to each other, with approximately 99% nucleotide homology. Furthermore, there is strong conservation among all Zika virus strains overall, with less than 12% divergence at the nucleotide level.119 This is important for diagnostic assays, which rely on precise sequences and epitopes, as well as for the development of therapeutics and vaccines. The current similarity data suggest that any vaccine product developed against any strain of Zika virus should be protective against all strains. The very nature of the close relatedness among the flaviviruses is responsible for the challenges in developing diagnostic algorithms for distinguishing among these viruses