Yellow Fever Vaccine

What it is and how it works

Contains live attenuated yellow fever virus (17D strain) grown in chick embryos. A single dose induces neutralising antibodies in most recipients within about 10 days, and WHO considers one dose to provide life-long protection for most people.

Indications

Active immunisation against yellow fever in persons aged 9 months and over travelling to or living in endemic areas, persons travelling to countries requiring an international certificate of vaccination, and laboratory workers handling the virus.

Dosage and administration (summary)

A single 0.5 mL dose by subcutaneous (or intramuscular, depending on the product) injection, given at least 10 days before travel; booster doses only in specific circumstances according to national recommendations.

Contraindications

Age under 6 months; severe hypersensitivity to eggs, chicken proteins or other components; immunodeficiency (congenital, acquired including symptomatic HIV or low CD4 counts, or immunosuppressive therapy); history of thymus dysfunction or thymectomy.

Warnings and precautions

Rare serious adverse events include yellow fever vaccine–associated neurotropic and viscerotropic disease; the risk is higher in people aged 60 years and over and in infants 6–9 months, so vaccination should be given only when the risk of infection is significant. Breast-feeding women should receive the vaccine only if exposure is unavoidable, because transmission to infants has been reported. Give simultaneously with or at least 4 weeks apart from other live vaccines.

Pregnancy

Generally avoided in pregnancy; may be given if travel to a high-risk area is unavoidable.

Storage and supply

Store refrigerated at 2–8 °C, protected from light; do not freeze; use promptly after reconstitution.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.