By Maggie Fox

A new global map calculating when and where Zika virus is likely to spread shows 2 billion people could be in the Zika zone.

Nearly 300 million people in the Americas live in areas where the mosquitoes that spread Zika thrive, and more than 5 million babies a year are born to women living in these areas, the team at the University of Washington, Oxford University and elsewhere report in the journal ELife.