Varicella Virus Vaccine

What it is and how it works

Contains live attenuated varicella-zoster virus (Oka-derived strain) that replicates to a limited extent after injection, inducing humoral and cell-mediated immunity against chickenpox without causing significant disease in immunocompetent individuals.

Indications

Active immunisation against varicella (chickenpox) in susceptible individuals from 12 months of age, including adolescents and adults without evidence of immunity; post-exposure prophylaxis when given within 3–5 days of exposure.

Dosage and administration (summary)

Two doses of 0.5 mL by subcutaneous (or, for some products, intramuscular) injection; in adolescents and adults the doses are given at least 4–6 weeks apart, according to the national immunisation schedule.

Contraindications

Primary or acquired immunodeficiency or immunosuppressive therapy; pregnancy; active untreated tuberculosis; severe hypersensitivity to vaccine components (e.g. neomycin, gelatin); acute severe febrile illness.

Warnings and precautions

Avoid pregnancy for 1 month after vaccination. Vaccinees who develop a rash should avoid close contact with susceptible high-risk individuals because of rare transmission of vaccine virus. Avoid salicylates for 6 weeks after vaccination (risk of Reye’s syndrome); recent immunoglobulin or blood products may reduce the immune response.

Pregnancy

Contraindicated in pregnancy.

Storage and supply

Store refrigerated at 2–8 °C or frozen, according to the product, protected from light; 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.