Contents

22 Zoster (herpes zoster/shingles)

22.4 Vaccine

Herpes zoster vaccine (HZV) is not on the Schedule.

22.4.1 Available vaccine

HZV (Zostavax, Merck) is a live attenuated virus vaccine. It is a higher titre formulation of the varicella vaccine and has been tested as a vaccine to protect against herpes zoster.9 By mimicking the immune response seen following a dose of shingles and boosting cell-mediated immunity in older adults, the incidence and severity of HZ is reduced by the high-titre vaccine.

Each HZV dose contains a minimum of 19,400 plaque-forming units (PFU) of the Oka/Merck strain of VZV. Other components include sucrose, hydrolysed porcine gelatin, urea, sodium chloride, monosodium L-glutamate, sodium phosphate dibasic, potassium phosphate monobasic, potassium chloride, residual components of MRC-5 cells (including DNA and protein), and trace quantities of neomycin and bovine calf serum. The vaccine contains no preservative.

22.4.2 Efficacy and effectivenessTop

In a large clinical trial (the Shingles Prevention Study) of 38,546 adults aged 60 years and older, with either a history of chickenpox or of having lived in the US for more than 30 years, the participants received the high-dose zoster vaccine or a placebo. The results showed that the zoster vaccine reduced the burden of illness of zoster by 61 percent in all age groups, by 65.5 percent in the age group 60–69 years, and by 55.4 percent in those aged 70 years and older. There was also a 66.5 percent reduction in post-herpetic neuralgia in all age groups.9 A cohort study of individuals in the US aged 65 years and older found zoster vaccine was associated with a 48 percent reduction in incident zoster, including a 37 percent reduction in those with immunosuppression.10

A review of the efficacy of HZV in preventing zoster and post-herpetic neuralgia concluded that zoster vaccine is safe, effective and highly recommended for the immunisation of immune-competent individuals over the age of 60 years.1

Duration of protection

The persistence of HZV efficacy was measured for seven years using a subgroup of individuals from the Shingles Prevention Study discussed above. Vaccine efficacy was statistically significant for the incidence of HZ and the HZ burden of illness through year five after vaccination.11 How long protection will last is not known and further doses may be required.

22.4.3 Transport, storage and handlingTop

Transport according to the National Guidelines for Vaccine Storage and Distribution.12 Store in the dark at +2oC to +8oC. The supplied diluent can be stored separately at room temperature (+20oC to +25oC), or in the refrigerator at +2oC to +8oC.

The vaccine must be reconstituted with the supplied diluent. Once reconstituted, HZV must be used within 30 minutes.

22.4.4 Dosage and administrationTop

HZV is registered for adults aged 50 years and older.

The dose of reconstituted HZV is 0.65 mL, to be administered subcutaneously in the deltoid muscle (see section 2.3).

Co-administration with other vaccines

HZV can be concurrently administered with influenza vaccine using separate syringes and sites. Recent evidence13 suggests that HZV can be concurrently delivered with 23PPV, despite earlier research to the contrary. The earlier research showed the average antibody titre against VZV was lower in individuals who received HZV and 23PPV at the same visit, compared to those who received these vaccines four weeks apart.

However, there is no evidence to suggest that antibodies against VZV are a measure of protection against HZ.14 The US Centers for Disease Control has not changed its recommendation for either vaccine and continues to recommend that HZV and 23PPV be administered at the same visit if the individual is eligible for both vaccines.14