The vaccine is one of the safest vaccines available and provides effective, long-lasting immunity. The vaccine will give protection for 10 years, beginning 10 days after vaccination. Vaccination is also recommended for laboratory personnel who might be exposed to virulent yellow fever virus. Infants under 9 months of age and pregnant women should be considered for vaccination if they must travel in a high-risk area and a high level of protection from mosquito exposure is not possible. Children under 4 months of age should not receive the vaccine because of the risk of developing encephalitis.
Severe reactions are extremely rare.
However, vaccination of persons with illness and fever should be postponed until recovery. Individuals with asymptomatic HIV infection may be offered the choice of immunization, if exposure can not be avoided. Individuals with the above contraindications should avoid travel to yellow fever areas. Specific information is not available on adverse effects of yellow fever vaccine on the developing fetus. Pregnant women who must travel to areas where the risk of yellow fever is high should be vaccinated.