For Which Adults Are RSV Vaccinations Cost-Effective?

Vaccines for respiratory syncytial virus (RSV) can reduce hospitalization and costs for older adults, and vaccination programs focused on patients with underlying medical conditions appear to be the most cost-effective, according to a new study in Canada.
For instance, vaccinating patients aged ≥ 70 years who have one or more chronic medical conditions was the best strategy for a cost-effectiveness threshold of $50,000 CAD per quality-adjusted life year (QALY), the authors wrote. 
“RSV is a common respiratory virus that can cause serious respiratory illness in older adults, resulting in hospitalization, admission to the intensive care unit, and death. The risk for severe RSV illness increases with age and with certain medical conditions,” lead author Ashleigh Tuite, PhD, manager of health economics and modeling at the Centre for Immunization Surveillance and Programs at the Public Health Agency of Canada, told Medscape Medical News.
“We now have authorized vaccines for RSV in Canada that have the potential to prevent disease and reduce healthcare and related costs,” she added. “Understanding the costs, benefits, and cost-effectiveness of potential RSV vaccination strategies can help with the development of vaccine program recommendations.”
The study was published online September 9 in CMAJ.
Model-Based Analysis
The investigators conducted a model-based cost-utility analysis of RSV vaccination programs across various age ranges and medical risks, looking at a combination of age-only, medical-risk-only, and age-plus-medical-risk-based strategies. They modeled medically attended RSV disease requiring either outpatient care (with a healthcare provider or emergency department visit) or inpatient care (through hospital admission, with or without intensive care unit admission).
Previous cost-effectiveness studies have focused on patients aged ≥ 60 or 65 years. Tuite and colleagues included patients aged ≥ 50 years, following a hypothetical population of 100,000 people over a 3-year period with three full RSV seasons and peak activity between January and March.
In the model, vaccine characteristics were based on the two RSV vaccines authorized for patients aged ≥ 60 years in Canada as of May 2024. The researchers assumed protection of 2-3 years in different scenarios. They calculated sequential incremental cost-effectiveness ratios (ICERs) in 2023 Canadian dollars per QALY from the healthcare system and societal perspectives, using a discount rate of 1.5% for costs and outcomes.
Without vaccination, the model estimated 120,000-144,000 RSV cases that required medical attention, 10,000-14,000 hospital admissions, and 1015 deaths annually among patients aged ≥ 60 years in Canada.
Age-based vaccination strategies decreased RSV disease burden and prevented between 20% and 40% of hospitalizations and deaths. Although more cases were averted when vaccination programs included patients of younger ages, universal age-based strategies didn’t efficiently use resources when compared with medical-risk-based strategies.
For both vaccines, a vaccination program focused on people with at least one chronic medical condition at ages ≥ 70 years was the optimal strategy for a cost-effectiveness threshold of $50,000 per QALY. Lowering the age to 60 years led to an ICER of $100,000 per QALY gained. Other age- and risk-based strategies exceeded commonly used cost-effectiveness thresholds.
In some locations with higher disease risks and higher healthcare costs, such as remote communities in northern Canada, broader vaccination programs across more ages may be cost-effective as well, the authors wrote.
“Although we found that broader, age-based vaccination programs were not the best use of resources when programs focused on medical risk were an option, there may be other reasons why age-based programs would be preferred,” said Tuite. “For instance, an age-based program may make it easier for healthcare providers to identify people eligible for vaccination, which in turn, may increase vaccine uptake.”
Implementing Vaccine Programs
Canada’s National Advisory Committee on Immunization recommends RSV vaccination for patients aged ≥ 75 years, as well as those aged ≥ 60 years who live in nursing homes and other long-term care facilities. So far, Ontario has announced a publicly funded vaccination program for patients aged ≥ 60 years living in long-term care homes, Elder Care Lodges, and some retirement homes, as well as patients receiving dialysis, recipients of solid organ or stem cell transplants, people experiencing homelessness, and those who identify as First Nations, Inuit, or Métis.
As vaccination programs are introduced across the country, public health officials will gain a better understanding of how RSV vaccines perform in different patient groups, which will help researchers to improve their estimates, said Tuite.
But implementing medical-risk-based strategies over age-based strategies might be difficult and unlikely from a practical standpoint.
“In the real world, asking someone to declare their medical conditions to be eligible for a vaccine increases the risk of inequities, where more affluent individuals may be able and willing to declare their condition and be vaccinated, while those who cannot or do not would be those who would benefit most from being vaccinated,” said Caroline Quach-Thanh, MD, professor of microbiology, infectious diseases, immunology, and pediatrics at the University of Montreal.
Quach-Thanh, who wasn’t involved with this study, has researched vaccine readiness and uptake across Canada for numerous viruses, including RSV, SARS-CoV-2, and influenza.
“It will be interesting to see which Canadian provinces and territories will implement a public adult RSV vaccination program in the coming year, as it comes with an important budgetary impact,” she said. “Once implemented, vaccine effectiveness against medically attended outpatient visits and hospitalizations, and the duration of protection (≥ 2 years) will need to be followed. The acceptability of these vaccine programs and vaccine coverage should also be followed.”
The authors reported no specific funding for this study but declared financial support from and affiliations with organizations such as the Canadian Institutes of Health Research, SickKids, and the National Advisory Committee on Immunization RSV Working Group. Tuite and Quach-Thanh reported no relevant disclosures.
Carolyn Crist is a health and medical journalist who reports on the latest studies for Medscape Medical News, MDedge, and WebMD.
 
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