Scientists have found a possible chink in the Zika virus's armour after mapping its structure.
Near atomic-level images of the virus show strong similarities to the dengue virus, which like Zika is spread by mosquitoes and causes a fever.
They also reveal a potential weakness - a variation inside the virus's outer shell of sugary proteins.
Understanding the way the virus is made could provide clues to how Zika invades human cells and suggest targets for drug treatments or vaccines.
Professor Richard Kuhn, director of Purdue University's Institute for Inflammation, Immunology and Infectious diseases in the US, who led the research, said: "Determining the structure greatly advances our understanding of Zika - a virus about which little is known. It illuminates the most promising areas for further testing and research to combat infection."
Zika has been associated with a birth defect called microcephaly that causes babies to be born with abnormally small heads and to suffer brain damage. It is also linked to the autoimmune disease Guillain-Barre syndrome, which can lead to paralysis.