Zika virus seems to be spreading at a far more accelerated rate than previously anticipated according to a report from the World Health Organisation. The virus has been spreading through the Americas, having ravaged Brazil over the last few months. The mosquito-borne illness which can cause the birth defect microcephaly can have symptoms as mild as joint pain and rashes. Due to the rapid rate of infection, health organisations are now investigating a possible vaccine in order to curb the amount of cases that occur. The virus is spread by Aedes mosquitoes, which are present in all of the Americas except Chile and Canada. It was reported last week that the first baby in the United States had been born with microcephaly linked to the Zika virus in a Hawaii hospital. The woman was living in Brazil for a time according to USNews.com. A travel warning for pregnant women remains in place in the following countries: Brazil, Colombia, El Salvador, French Guiana, Guatemala, Guyana, Haiti, Honduras, Martinique, Mexico, Panama, Paraguay, Saint Martin, Suriname, Venezuela, Puerto Rico, Barbados, Bolivia, Ecuador, Guadeloupe, Saint Martin, Guyana, Cape Verde, and Samoa. Lead image via Caltech