When You're Traveling by Jacqueline Tresl, RN Yellow fever is a mosquito-spread virus that occurs in Africa and South America.
Symptoms appear three to six days after exposure and include headache, vomiting, fever and jaundice.
Get immunized before you travel to these countries. Get a vaccine to prevent yellow fever. The virus is made from 17D yellow fever virus strain and grown inside chick embryos. Carry a Certificate of Vaccination, issued by your health department, with you whenever you travel to South America and Africa. Many countries in these regions will not permit you to enter without a vaccination certificate or a medical waiver.