Writing in a US medical journal, they called on the WHO to heed lessons from the Ebola outbreak and convene an emergency committee of disease experts.
They said a vaccine might be ready for testing in two years but it could be a decade before it is publicly available.
Zika, linked to shrunken brains in children, has caused panic in Brazil.
Thousands of people have been infected there and it has spread to some 20 countries.
Would it be wrong to eradicate mosquitoes?
The Brazilian President, Dilma Roussef, has urged Latin America to unite in combating the virus.
She told a summit in Ecuador that sharing knowledge about the disease was the only way that it would be beaten. A meeting of regional health ministers has been called for next week. Read more on bbc.