Herpes zoster vaccine: What are the potential benefits for the ageing and older adults?

The burden of illness and healthcare resource utilisation associated with herpes zoster in individuals aged 50 years or above is substantial, causing severe loss of quality of life (QoL). Herpes zoster incidence varies from 1.5 to 5.0 per 1000 person-years in adults of all ages, and reaches 10 cases per 1000 person-years in individuals aged over 60. The most frequent and debilitating complication is post-herpetic neuralgia (PHN). In the absence of antiviral therapy, up to 45% of over 60-year-old experience pain which persists for 6 months to a year. The importance of preventive strategies for PHN is becoming widely recognised. Several systematic reviews confirm that short-term benefit can be gained from antiviral drugs, with limited evidence that they reduce the incidence of PHN. Complementary analgesic drugs are often required. However, prescribing advised medications in old, frail, co-morbid and poly-medicated patients must be carefully considered, as there may be contraindications. Consequently, the difficulties in effectively treating HZ and severe, often intractable PHN that may follow provide a strong argument for the development of effective immunization strategies. In the Shingles Prevention Study, a placebo-controlled trial in adults aged 60 years or more, the HZ vaccine led to a sustained boost of specific cell-mediated immunity with a good tolerance. In older adults, the HZ vaccine has the potential of significantly reducing the HZ burden of illness by decreasing the incidence of HZ or reducing its severity. This review aims to detail and analyse the potential benefits of this immunization.