Neurotropic disease after vaccination against yellow fever

: Millions of people are vaccinated each year to prevent morbidity and mortality by numerous bacterial and viral infections. Safety of vaccines is an important topic of discussion, especially because of the prophylactic nature of vaccination. Luckily, serious adverse events are rare. However, low incidence results in low awareness, and thus can make identification of these post-vaccination diseases difficult for healthcare workers. In the Netherlands, serious adverse events caused by travel vaccinations are especially rare, because of the low immunisation coverage compared to endemic countries. We present two Dutch cases that were diagnostically challenging. Both turned out to suffer from a serious adverse event of vaccination with live attenuated yellow fever virus, so-called yellow fever associated neurotropic disease (YEL-AND). With this article we hope to improve awareness of post-vaccination diseases, and YEL-AND in particular.