Scientists have mapped the structure of the Zika virus and found a possible chink in its armour.
Near atomic-level images of the virus show strong similarities to the dengue virus, which is also spread by mosquitoes and causes fever.
They also reveal a potential weakness, a variation in Zika'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.
Most infected individuals experience mild flu-like symptoms and skin rashes.
Zika virus transmission has been reported in 33 countries, with increased rates of microcephaly occurring in Brazil and French Polynesia.
In February, the World Health Organisation (WHO) declared Zika to be a "public health emergency of international concern".
The research is reported in the journal Science.