YF-Vax

Yellow fever vaccine is a vaccine that protects against yellow fever.[4] Yellow fever is a viral infection that occurs in Africa and South America.[4] Most people begin to develop immunity within ten days of vaccination and 99 percent are protected within one month, and this appears to be lifelong.[4] The vaccine can be used to control outbreaks of disease.[4] It is given either by injection into a muscle or just under the skin.... [wikipedia]