Because room for error is slim for a species on the brink of extinction, most instances of vaccine use have been limited to emergency responses during ongoing outbreaks. (sciencenews.org)
That's why the US government have been advising travelers who are pregnant or trying to get pregnant to avoid areas with an ongoing outbreak. (businessinsider.com)
The Brazilian Ministry of Health reported an ongoing outbreak in December 2016. (sciencedaily.com)