Yellow Fever Yellow fever is a viral disease transmitted by mosquitos in parts of Africa and South America. The spectrum of illness ranges from a flu-like syndrome to severe hepatitis and hemorrhagic fever. In addition to vaccination, travelers should take personal protective measures against exposure to mosquitos when traveling in areas where yellow fever occurs. Initially, yellow fever vaccine consists of one dose which should be given at least ten days prior to arrival in an infected area. The period of protection is about ten years and can be extended by revaccination. The vaccine can only be given at a designated Yellow Fever Vaccination Center and, when required for entry into a country, must be documented on the International Certificate of Vaccination. If you wish to receive yellow fever vaccine, please call us for a clinic appointment.