Question: how long is typhoid vaccine effective?
Answer: The product information for Vivotif Oral live attenuated vaccine recommends a booster every 3 years. For people at ongoing risk of typhoid fever, ATAGI also recommends revaccination with a 3- or 4-dose course of the oral live attenuated vaccine 3 years after a 3-dose course, or 5 years after a 4-dose course.