hepatitis b antigen: clinical use

Prescribing considerations

• Confirm that the patient is aged at least 15 years and has renal insufficiency within the licensed indication.
• Consider whether infection could pre-date vaccination; the vaccine does not treat established hepatitis B.
• Avoid switching hepatitis B vaccines after starting a primary course with this product.
• Record the product name and batch number for traceability.
• Ensure facilities and trained staff are available to manage anaphylaxis.

Contraindications and cautions

• Hypersensitivity to the active substance, an excipient or a previous hepatitis B vaccine.
• Postpone during an acute severe febrile illness; a minor infection such as a cold is not a contraindication.
• Never administer intravenously or intradermally; avoid gluteal administration because it may produce a suboptimal response.

Monitoring

• Assess vaccine response serologically because response and antibody persistence may be reduced in renal insufficiency.
• Continue anti-HBs monitoring in people with kidney failure and act according to current national recommendations if protection falls below the accepted threshold.
• Observe for immediate hypersensitivity and prevent injury in patients prone to injection-related syncope.

Clinical pharmacology

Recombinant hepatitis B surface antigen induces specific anti-HBs humoral antibodies. It is adsorbed onto aluminium phosphate and combined with monophosphoryl lipid A in the AS04C adjuvant system. Pharmacokinetics have not been studied because protection is mediated through the immune response.

Formulation and product differences

• Turbid white suspension supplied in a pre-filled syringe.
• Contains recombinant surface antigen produced in yeast and the AS04C adjuvant system.
• Essentially sodium-free, contains no live hepatitis B virus and must not be mixed with other medicinal products.