For the prevention of yellow fever, a single vaccination with 17-D nonpathogenic strain of virus gives full protection to the individual for at least

.17D vaccine is a live attenuated vaccine,prepared from a non virulent strain grown in chick embryo cells and subsequently freeze dried.sensitivity to heat is a major drawback.vaccine is administered subcutaneously at the inseion of deltoid single dose of 0.5 ml, irrespective of age.immunity begins to appear by 7th day and continues for about 35 years.however WHO RECOMMENDS REVACCINATION AFTER EVERY 10 YEARS. ref:park&;s textbook,ed 22,pg no 258