As Zika spreads across the globe, more and more countries are being declared out of bounds for pregnant women - or women planning pregnancy. In addition to South American nations, Singapore, Thailand, Florida and the Philippines have all been added to the high-risk list, making the mosquito-borne disease an increasingly global problem.

Currently there is no treatment for the Zika virus, which can lead to microcephaly - abnormally small heads - in babies who are infected in utero, as well as placenta damage, which can slow foetal growth and can often be fatal. But that looks set to change, as this week, researchers at the Washington University School of Medicine in St. Louis and Vanderbilt University School of Medicine have identified a human antibody that prevents the foetus in pregnant mice from becoming infected with Zika. The antibody also prevented placental damage in the mice and protects adult mice from the disease.

There could soon be a Zika vaccine for pregnant women

"This is the first antiviral that has been shown to work in pregnancy to protect developing fetuses from Zika virus," Professor Michael Diamond, the study's co-senior author, says in the study's press release. "This is proof of principle that Zika virus during pregnancy is treatable, and we already have a human antibody that treats it, at least in mice."

Studies to determine whether the antibody will have the same effect on humans are yet to be done, but it's a massive step in the fight against Zika. The study was published this week in Nature, as a fast-track advance online publication. 

There could soon be a Zika vaccine for pregnant women