Zika virus likely to spread throughout the Americas, says WHO

Drug companies evaluate existing vaccine technology as only Canada and Chile expected to be free of mosquito-borne disease

Two of the world's biggest drug companies are evaluating whether existing vaccine technology could be used against the Zika virus, as the World Health Organisation warned the mosquito-borne virus was likely to spread to all countries in the Americas except for Canada and Chile.

The WHO director general, Margaret Chan, told the organisation's executive board that she had asked Carissa Etienne, head of the WHO in the Americas, to brief the board later this week on its response to the outbreak. The mosquito-borne Zika virus has been linked to brain deformities in babies.