varicella-zoster virus: clinical use

Prescribing considerations

• Confirm whether prevention of primary chickenpox or shingles is intended; Shingrix is not licensed to prevent primary chickenpox.
• Assess pregnancy, immune status, acute febrile illness, allergy history, bleeding risk, blood products and concurrent vaccination.
• Record the product name and batch number for biological traceability.
• For Varilrix in people at high risk of severe chickenpox, specialist assessment of immune competence is essential.

Contraindications and cautions

• Shingrix: hypersensitivity to an active substance or excipient.
• Varilrix: pregnancy; severe humoral or cellular immunodeficiency or specified immunosuppressive treatment; hypersensitivity to the vaccine, an excipient or neomycin, except contact dermatitis alone.
• Postpone either vaccine during an acute severe febrile illness.

Monitoring

• Ensure immediate treatment and supervision are available for anaphylaxis.
• Prevent injury from vaccination-related syncope.
• For Varilrix, promptly assess neurological symptoms or a generalised vesicular rash, particularly in an immunocompromised recipient.
• Monitor and report suspected adverse reactions through the UK Yellow Card scheme.

Clinical pharmacology

Varilrix contains live attenuated Oka-strain virus. Shingrix contains recombinant glycoprotein E with the liposomal AS01B adjuvant; conventional pharmacokinetic assessment is not applicable to either vaccine.

Formulation and product differences

• Shingrix is a non-live recombinant glycoprotein-E powder supplied with a separate adjuvant suspension; it is given intramuscularly after reconstitution.
• Varilrix is live attenuated Oka-strain virus supplied as powder with solvent; after reconstitution it may be given subcutaneously or intramuscularly.
• The products have different licensed uses, contraindications, routes and handling requirements and should not be substituted for one another.