A health technology assessment (HTA) is intended to support evidence-based decision-making in regard to the optimum use of resources in healthcare services. Measured investment and disinvestment decisions are essential to ensure that overall population health gain is maximised, particularly given finite healthcare budgets and increasing demands for services provided. 

HIQA undertook this assessment at the request of the Department of Health following a clinical recommendation from the National Immunisation Advisory Committee (NIAC). The aim of the HTA was to establish the clinical effectiveness, cost effectiveness and budget impact of the addition of herpes zoster (shingles) vaccination to the adult immunisation programme in Ireland. The HTA will be provided as advice to the Minister for Health to inform a policy decision on whether to include herpes zoster vaccination in the adult immunisation programme in Ireland.

This research was carried out in accordance with HIQA’s guidelines for the conduct of HTAs. In summary:

• The terms of reference for the HTA were agreed between HIQA and the Department of Health. 
• An Expert Advisory Group (EAG) was convened comprising representation from the Department of Health, the National Immunisation Advisory Committee, the National Immunisation Office, the Health Protection Surveillance Centre, and the Irish College of General Practitioners. The EAG also included clinicians with specialist expertise in infectious diseases and public health, healthcare professionals from public health and general practice nursing, representatives from relevant patient advocacy groups and methodological experts.
• A protocol for the work to be undertaken was reviewed by the HIQA EAG and published on the HIQA website.
• The epidemiology of herpes zoster in Ireland was described.
• The technology — that is, the recombinant adjuvanted zoster vaccine — was described. 
• A systematic review of the clinical efficacy, effectiveness and safety of herpes zoster vaccination was conducted. 
• A rapid review was conducted to assess the most up-to-date international evidence on the approaches taken to the economic modelling of herpes zoster vaccination, and to inform the development of a de novo economic model for Ireland.
• An economic model was developed to estimate the cost effectiveness and budget impact of the potential introduction of herpes zoster vaccination for adults in Ireland. 
• Analyses of the organisational, social and ethical implications of the proposed introduction of a herpes zoster vaccination programme were undertaken.
• The draft HTA report was reviewed by the EAG. The report was then made available for a six-week public consultation period, during which members of the general public and stakeholder organisations had the opportunity to provide feedback on the draft HTA report. A statement of outcomes outlining HIQA’s response to the consultation feedback was drafted, with changes made to the HTA report, as appropriate.
• A final draft report along with the draft statement of outcomes were submitted to the Board of HIQA for approval. Following their approval, the final assessment was submitted to the Minister for Health and the HSE as advice, with both documents published on the HIQA website.

• Herpes zoster (HZ), commonly known as shingles, is characterised by a painful, blistering rash that typically takes two to four weeks to resolve. Among those with a history of varicella (chicken pox), the individual life-time risk of developing HZ is approximately 30%. The most frequent complication of HZ is post-herpetic neuralgia (PHN), referring to persistent chronic pain after the resolution of the acute rash. PHN can significantly alter individuals' lives, inflicting debilitating pain, disrupting daily activities, sleep, and emotional wellbeing. The probability of PHN after HZ increases with age, increasing from a one in 10 chance in 50- to 59-year-olds to one in five in those aged over 80 years.
• Both the risk of HZ and complications from HZ increase with age after 50 years and among individuals who are immunocompromised due to immunosuppressive conditions or therapies.
• There is clear and consistent evidence that the recombinant adjuvanted vaccine (RZV) vaccine is safe and effective at reducing HZ cases, but that its effectiveness diminishes over time. While local and systemic adverse events are common, serious adverse events are uncommon.
• At the submitted price, the current evidence suggests that HZ vaccination does not represent an efficient use of healthcare resources in Ireland. 
  • The incremental cost-effectiveness ratios (ICERs) for the general population ranged from €127,825 per quality-adjusted life year (QALY) gained for vaccination at age 80, to €979,815 per QALY gained for vaccination at age 50. 
  • Based on the assumptions in the model, at a willingness-to-pay threshold of €45,000 per QALY, the vaccine cost would need to be reduced by at least 80% for HZ vaccination at age 75 or at age 80 to be cost effective.
  • Considering a vaccine uptake of 50%, the five-year incremental budget impact of a HZ vaccination programme for:
    • adults as they turn 65 years old (no catch up for older adults) would be €53.3 million.
    • all adults aged 65 years and older, as recommended by the National Immunisation Advisory Committee (NIAC), would be €218 million. 
  • The five-year incremental budget for eligible immunocompromised persons as recommended by NIAC (with 100% coverage) was estimated at €56.2 million. This estimate comprised €46.3 million for the cohort aged 50 years and older with non-specific immunocompromising conditions, and €9.8 million for specific groups including those with haematological malignancies, solid organ transplant recipients, haematopoietic stem cell transplant (HSCT) recipients and those with advanced/untreated HIV. 
• A decision to fund the RZV vaccine as part of the adult programme could have significant financial and logistical implications depending on the population groups for whom the vaccine is funded. RZV vaccination is given as a two-dose schedule. A staggered roll-out approach would be required if vaccination was extended to all individuals included in the NIAC recommendations (approximately 850,000 in the first year and 53,000 each year after that).
• While the addition of the HZ vaccine to the adult immunisation programme would improve equity of access to this vaccine, the use of resources in this way may create inequity in other areas of the healthcare system. In the context of a finite healthcare budget, it could require reallocation of resources, potentially impacting the existing healthcare system by diverting resources from other effective treatments or from the overall healthcare fund. Funding interventions, which have been found to be not cost effective, could create issues of justice and equity with respect to a fair distribution of benefits and burdens.