Measles virus live attenuated + Mumps virus live attenuated + Rubella virus live attenuated + Varicella-Zoster virus live attenuated (Oka strain): clinical use

Prescribing considerations

• Confirm eligibility under current national recommendations and review previous relevant vaccines.
• Postpone during acute severe febrile illness, but not solely for a minor infection without significant fever.
• Assess personal or family history of febrile convulsions; risk is increased after the first combined MMRV vaccination compared with separate MMR and varicella vaccines.
• Review thrombocytopenia or coagulation disorders and consider the subcutaneous route.
• Assess immediate egg reactions carefully; severe egg anaphylaxis requires caution and access to treatment.
• Record the product name and batch number.

Contraindications and cautions

• Pregnancy
• Severe humoral or cellular immunodeficiency
• Current significant immunosuppressive therapy, including high-dose systemic corticosteroids
• Anaphylaxis or other hypersensitivity to a previous measles-, mumps-, rubella- or varicella-containing vaccine
• Hypersensitivity to an active substance, excipient or neomycin; contact dermatitis to neomycin alone is not a contraindication

Monitoring

• Ensure anaphylaxis treatment is immediately available.
• Advise carers about fever, febrile convulsions and when urgent assessment is required.
• Monitor immunocompromised recipients who are not formally contraindicated because protection may be reduced.
• If a varicella-like rash develops, advise avoiding close contact with susceptible high-risk people; vaccine-strain transmission is very uncommon.
• Report suspected adverse reactions through the Yellow Card scheme.

Clinical pharmacology

Live attenuated Schwarz measles, RIT 4385 mumps, Wistar RA 27/3 rubella and Oka varicella strains induce humoral and cellular immune responses. Pharmacokinetic assessment is not applicable to vaccines.

Formulation and product differences

• Priorix Tetra is supplied as powder in a vial with solvent in a pre-filled syringe and requires reconstitution.
• The reconstituted solution may range from clear peach to fuchsia pink and contain translucent product-related particles; abnormal colour or other particles require disposal.
• It contains trace neomycin, sorbitol, phenylalanine and para-aminobenzoic acid.
• Unlike ProQuad, Priorix Tetra does not contain porcine gelatine.
• After reconstitution, follow the SmPC storage and disposal limits.