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. 

The aim of this HTA was to establish the clinical effectiveness and safety, cost effectiveness, and budget impact associated with alternative infant and adult immunisation strategies against RSV in Ireland. The HTA was submitted as evidence-based advice to inform decision-making by the Minister for Health and the HSE.

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

• The Terms of Reference of the HTA were agreed between HIQA and the Department of Health.
• An Expert Advisory Group (EAG) was convened with representation from key stakeholders including advocacy groups representing infants and older adults, decision makers, clinical experts, public health experts and methodological expertise.
• A protocol outlining the proposed methodology was reviewed by the EAG and following incorporation of feedback, as appropriate, the final protocol was published on the HIQA website.
• A description of the technology (immunisation against RSV) was prepared.
• The health technology developers of the RSV immunisation products were offered the opportunity to provide a factual accuracy check.
• The epidemiology and burden of the disease was described separately for the two populations of interest — infants and older adults.
• Systematic reviews of the clinical efficacy, effectiveness and safety of authorised interventions and approaches for the immunisation of infants and older adults RSV were completed.
• Cost-utility analyses of alternative immunisation strategies for infants and older adults were conducted.
• Budget impact analyses were undertaken to assess the budget impact of implementing alternative infant and adult RSV immunisation programmes.
• The potential organisational and resource implications of implementing infant and adult RSV immunisation programmes were examined.
• The ethical, patient and social implications relevant to the immunisation strategies for infants and older adults were examined.
• 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 was submitted to the Board of HIQA for approval. Following its approval, the final assessment was submitted to the Minister for Health and the HSE as advice, and published on the HIQA website along with the statement of outcomes report.

HIQA’s advice is in the context of the general infant population and assumes the ongoing immunisation of infants and children up to two years of age at high risk of severe disease (that is, those previously identified as eligible for palivizumab in line with recommendations from the National Immunisation Advisory Committee).

• RSV is a highly contagious seasonal virus which can cause serious complications particularly in infants and young children. RSV has a substantial and predictable seasonal impact on families and on the Irish healthcare system.
• In those aged less than two years, data for the period 2018 to 2024 indicate that RSV resulted in almost 1,800 hospital discharges each year, of which 87% were in those aged less than one year. On average, 130 discharges included an ICU stay, 91% of which were in infants aged less than one year. This considerable burden was in the context of an established immunisation programme that offers RSV immunisation to infants and children at high risk of severe disease (that is, those previously eligible for palivizumab). 
• The identified incidence data are likely an underestimate of the total burden, particularly in primary care and emergency departments, as they are influenced by testing policy and practices.
• RSV poses a significant challenge for paediatric healthcare services, as a high proportion of hospital discharges occur between October and December. These seasonal RSV surges impact delivery of scheduled and unscheduled care, increasing pressure on staff and the risk of hospital-acquired infection, challenging the ability to provide safe and effective care, and undermining the resilience of the healthcare system.
• There is consistent evidence that the RSV immunisation products considered in this HTA (extended half-life monoclonal antibodies [EHL-mAbs] and maternal vaccine) are safe and effective for the prevention of RSV and associated complications in infants, over one season. While local and systemic events are common, serious adverse events are rare. 
• For all strategies modelled, expanding RSV immunisation to include the general population of infants would result in significant reductions in medically attended cases and RSV-related hospitalisations. The results of the analyses for a strategy offering an EHL-mAb to those born during the RSV season broadly aligned with the positive findings reported by the HSE for the 2024/25 Pathfinder RSV immunisation programme.
• In the absence of list prices for all the interventions considered, and the potential for price reductions through competitive tender, there is considerable uncertainty in relation to their likely cost and relative cost to the HSE. At assumed prices (ex-VAT) of €301 and €165 for an EHL-mAb and maternal vaccine, the estimated five-year incremental budget impact ranged from €15.6 million for a strategy based on seasonal maternal vaccination to €58.5 million for a strategy offering an EHL-mAb to those born during or entering their first RSV season (seasonal EHL-mAb plus catch-up).
• Given the assumptions of the economic model and considering a willingness to pay (WTP) threshold of €45,000 per QALY:
  • A seasonal EHL-mAb plus catch-up strategy would deliver the highest health gain (most QALYs) but would also be the most costly. 
  • At a price of €166 or less (ex VAT) for the EHL-mAb and a price of at least €90 for the maternal vaccine, the seasonal EHL-mAb plus catch-up strategy would be cost effective.
  • At a price of €47 or less (ex VAT) for the maternal vaccine and a price of at least €190 for the EHL-mAb, the maternal vaccine strategy would be cost effective.
• In the event of a long-term policy decision to provide RSV immunisation for the general population of infants, it will be important to consider:
  • the unique information campaign requirements, organisational and resource implications of the alternative strategies, including any requirement to recruit and train healthcare workers to deliver the strategy.
  • the need for ongoing programme evaluation to ensure the best possible outcomes for the resources allocated. This should include monitoring uptake in the target population, and linkage of vaccination records, where appropriate.

• Respiratory syncytial virus (RSV) is a highly contagious seasonal virus. In healthy individuals, infection with RSV is usually self-limiting; however, complications can occur. Older adults, particularly those with certain underlying health conditions and residents of long-term care facilities are among those vulnerable to serious complications, which can be fatal.
• The number of recorded hospital discharges with a primary diagnosis of RSV in older adults is relatively low but has increased in recent years (average of 119 discharges per annum between 2022 and 2024). This is likely due to improved ascertainment arising from changes in testing practices.
• The burden of RSV increases with age. Despite representing only a quarter of the population aged 65 years and older, those aged 80 years and older account for almost half of all notified cases, RSV-related ED visits and RSV-related hospital admissions, as well as more than two thirds of the mortality in this age group.
• The currently authorised RSV vaccines are authorised as a single (once-off) dose, as the need for a booster has not been confirmed. There is consistent evidence that they are safe and effective for the prevention of RSV and associated complications. While local and systemic events are common, serious adverse events are rare. There is evidence of longer-term effectiveness, with data limited to a maximum of three years’ follow-up; however, immunity wanes over time.
• At currently available list prices of €165 (ex VAT) for the adult vaccine, the estimated five-year incremental budget impact for the age-based strategies modelled for older adults ranged from €70.6 million to €73.7 million.
  • The estimated total five-year budget impact for the full cohort of adults aged 60 years and over with additional risk factors for severe disease due to comorbidity or who are resident in a long-term care facility was estimated at €93.4 million, €7.9 million of which related to residents of LTCFs.
• Given the assumptions of the economic model and considering a willingness to pay threshold of €45,000 per quality-adjusted life year (QALY):
  • At currently available list prices of €165 (ex VAT), none of the strategies modelled would be cost effective.
  • A strategy of providing immunisation to those aged 80 years and older in year one of the programme and those aged 80 years only in subsequent years would be cost effective at a vaccine price of €20 or less (ex VAT), that is an 88% reduction relative to currently available list prices.
• In the event of a decision to implement an RSV immunisation programme for older adults, it would be important to consider:
  • The potential scheduling challenges given existing seasonal influenza and COVID-19 vaccination programmes, with the RSV vaccine representing a third seasonal vaccine.
  • An information campaign and materials to clearly communicate the eligible population, and the potential benefits and harms of RSV immunisation. This should include resources to support uptake in under-represented or hard-to-reach groups.
  • The need for ongoing programme evaluation to ensure the best possible outcomes for the resources allocated. This should include monitoring uptake in the target population.