American scientists studying the Zika virus have warned that it could be a decade before a vaccine is publicly available.
The virus is linked to shrunken brains in unborn children, leading to severe brain damage or death.
It has spread to more than 20 countries, and has caused panic in Brazil where thousands of people have been infected.
There is currently no vaccine or cure, and diagnostic testing is difficult.
The search for a vaccine is being led by scientists at the University of Texas Medical Branch.