Varicella, Live Attenuated

What it is and how it works

Contains live attenuated varicella-zoster virus (Oka 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 healthy adolescents and adults, non-immune healthcare workers and close contacts of immunocompromised patients; post-exposure prophylaxis if 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, given at least 4–6 weeks apart in adolescents and adults, according to the national immunisation schedule.

Contraindications

Primary or acquired immunodeficiency, including high-dose corticosteroid or other immunosuppressive therapy, leukaemia or lymphoma; pregnancy; active untreated tuberculosis; severe hypersensitivity to vaccine components such as neomycin or gelatin; acute severe febrile illness.

Warnings and precautions

Pregnancy should be avoided for 1 month after vaccination. Vaccine virus can rarely be transmitted to susceptible contacts from vaccinees who develop a rash; avoid close contact with high-risk individuals in that case. Salicylates should be avoided for 6 weeks after vaccination because of the risk of Reye’s syndrome; immunoglobulins or blood products may reduce the response.

Pregnancy

Contraindicated in pregnancy.

Storage and supply

Store refrigerated at 2–8 °C (some products may also be stored frozen), 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.