There is a single-shot vaccine for yellow fever, according to the Centers for Disease Control and Prevention. People visiting areas where yellow fever exists should obtain the vaccination at least 10 days prior to arrival. Additionally, some countries require proof of yellow fever vaccination as a condition for entry.
Most people between the ages of 9 months and 59 years can receive the yellow fever vaccination with little risk of severe side effects; however, vaccination may be contraindicated for people with compromised immune systems or a severe allergy to a component of the vaccine, notes the CDC. Furthermore, pregnant or nursing women should not receive the vaccine.