• Vaccine Name: Varivax
• Target Pathogen: Varicella-zoster virus
• Target Disease: chickenpox / shingles
• Product Name: Varicella Virus Vaccine Live
• Tradename: Varivax
• Manufacturer: Merck & Co., Inc.
• Vaccine Ontology ID: VO_0000119
• CDC CVX code: 21
• Type: Live, attenuated vaccine
• Status: Licensed
• Location Licensed: USA (License #0002)
• Host Species for Licensed Use: Human
• Antigen: OkaIMerck strain of live, attenuated varicella vlrus.
• Preparation: The OkaIMerck strain of live, attenuated varicella vlrus was initially obtained from a child with wild-type varicella, then introduced into human embryonic lung cell'cultures, adapted to and propagated in embryonic guinea pig cell cultures and finally propagated in human diploid cell cultures (WI-38). This live, attenuated varicella vaccine is a lyophllized preparation containing sucrose, phosphate, glutamate, processed gelatin, and urea as stabilizers. The product contains no preservative (FDA: Varivax).
• Immunization Route: Intradermal injection (i.d.)
• Storage: DO NOT FREEZE, store at 2 to 8°C or colder (36 to 46°F or colder).
• Approved Age for Licensed Use: 1 year and older
• Contraindication: A history of hypersensitivity to any component of the vaccine, including gelatin (FDA: Varivax).
• Description: Indication: For active immunization of persons 12 months of age and older.

Human Response

• Immune Response: Clinical trials with several formulations of VARIVAX containing the attenuated virus ranging from 1000 to 50,000 PFU per dose, have demonstrated that VARIVAX induces detectable immune responses and is generally well tolerated in healthy individuals ranging from 12 months to 55 years of age. VARIVAX was also found to induce cell-mediated immune responses in vaccinees (FDA: Varivax).
• Side Effects: Side effects of vaccination were mostly injection site redness and pain.
• Efficacy: The majority of subjects who received the vaccine and were exposed to wild-type virus were either completely protected from chickenpox or developed a milder form of the disease. Clinical studies have demonstrated continued protection up to 10 years after vaccination. Also, a boost in antibody levels has been observed in vaccinees following exposure to wild-type varicella as well as following a second dose of the vaccine (FDA: Varivax).