Abstract
Although antivirals can help reduce the severity and duration of acute herpes zoster (HZ), the best protection against the disease is to boost an individual’s immunity by vaccination with the live attenuated HZ vaccine. A new recombinant HZ subunit vaccine holds promise to further reduce the burden of HZ and its complications.
Key Points
- Herpes zoster (HZ) is common and associated with a considerable burden of morbidity.
- Vaccination against HZ is the most effective strategy to provide increased protection against both acute zoster and postherpetic neuralgia.
- A recommendation from the GP to receive the zoster vaccination is the most effective strategy to increase HZ vaccine coverage.
Herpes zoster (HZ), or shingles, is a neurocutaneous disease that occurs when varicella-zoster virus (VZV) latent in sensory ganglia reactivates and replicates to cause dermatomal pain and a vesicular rash.1,2 These events occur when VZV-specific cell-mediated immunity (CMI) falls below a critical level, which typically happens when it is compromised by disease, medical treatment or ageing.3 The exact triggers for reactivation of the virus in an individual are unknown.
Exogenous, circulating wild-type virus episodically boosts adult T cell immunity (e.g. through exposure to children with chickenpox) so that reactivation usually occurs as a result of naturally waning CMI with age or induced immunosuppression.4
Up to one-third of the population is at risk of developing HZ during their lifetime, and two-thirds of people with the disease are aged 50 years or older.5 In the Australian context, HZ affects 120,000 people every year.6
Risk factors
The increased incidence of HZ is most marked after 50 years of age and continues to rise with age. This is likely to be related to decline in CMI in older people.3 Other risk factors for HZ include: female sex, being immunocompromised and having a family history of HZ.7,8
Reactivation of VZV leads to a localised inflammatory response, with nerve-cell damage and subsequent ganglionitis. The degree of inflammation correlates with both the disease severity and the risk of complications.9
The risk and severity of HZ is considerably higher in immunosuppressed individuals and proportional to the severity of immunosuppression. Therefore, it is recommended that individuals consider, in conjunction with specialist advice, having HZ vaccination before starting immunosuppressive therapy.
Guidance on the use of the HZ vaccine in patients who are immunocompromised, developed by the National Centre for Immunisation Research and Surveillance (NCIRS),10 is summarised below in the section on Prevention. Discussions between GPs and specialists (e.g. a haematologist) on whether the HZ vaccine can be used in a particular patient who is immunocompromised is recommended.