Study Highlights Health, Economic Benefits of RSV Vaccine for Older Adults

New research published in Vaccine highlighted the potential of vaccination against respiratory syncytial virus (RSV) in older adults.

RSV is a common respiratory virus that typically causes cold-like symptoms that lead to lower respiratory infections and hospitalizations. While RSV in infants has been heavily researched, there are currently no approved pharmacological treatment or prevention methods for RSV infection in older adults aged 60 and older. Additionally, there is limited literature on the potential economic value of RSV vaccines in this age group.

In order to estimate both the magnitude of the clinical and economic burden of RSV and the general value-based price (VBP) of a potential RSV vaccine for older Americans, the authors developed a decision-tree model that included RSV-related outcomes, comparing the results of a hypothetical RSV vaccine to no vaccine. The model included epidemiology parameters as well as direct costs and quality-adjusted life years (QALYs) lost per case of illness QALYs lost per death.

The epidemiology parameters came from 2 previous studies. One was a landmark study that used community-based disease surveillance to estimate RSV incidence. The other used medical records to retrospectively look at RSV cases where patients needed medical attention and differentiated between mild and moderate disease.

“Specifically, our model structure categorizes all laboratory-confirmed RSV infections as either moderate-to-severe lower respiratory tract disease (msLRTD) or mild acute respiratory infection (mARI) based on the number of observed symptoms,” the authors explained.

The study found that a vaccine with 50% efficacy and coverage comparable with the influenza vaccine (65.3%) would prevent 43,700 to 81,500 RSV hospitalizations and 8000 to 14,900 RSV-related deaths per RSV season, which spans during the colder months from late fall to early spring.

This translates to 1800 to 3900 fewer quality-adjusted life-years (QALYs) lost and avoiding $557 to $1.024 billion in direct costs per year. VBPs in the 2 base-case analyses ranged from around $73 to $299, depending on the epidemiology parameters used.

“By explicitly incorporating RSV severity, the model can account for differences in resource utilization (e.g., hospitalization) and costs between severity levels and evaluate scenarios where vaccination attenuates the severity of breakthrough infections in those vaccinated, as observed with other respiratory vaccines.”

When using the epidemiology parameters derived from the community surveillance study, the estimated VBP per vaccination was $151.96 for a willingness to pay (WTP) threshold of $50,000 per QALY gained, and $289.79 for a WTP threshold of $100,000 per QALY gained.

For the co–base-case analysis using epidemiology parameters from Belongia and colleaguesthe study looking at RSV severity, the VBP estimates were $73.54 and $152.01 per vaccination for WTP thresholds of $50,000 and $100,000, respectively.

These estimates also changed slightly when taking into account the seasonality of RSV.

According to the authors, despite variability and gaps in the epidemiology literature, the findings provide further evidence of the significant burden of RSV disease older American adults face and the potential health and economic benefits of RSV vaccines, which would be comparable in price to other vaccines for older Americans.

“This burden is substantial relative to other vaccine-preventable diseases in older adults, with only influenza and pneumococcal disease exceeding the RSV disease economic burden ranging from $1.5 billion to $3.0 billion estimated in this analysis.” the authors said. They later added, “the modeling approach represents a general framework for future research addressing key remaining data gaps, notably RSV-specific costs and utilities and a more complete understanding of the long-term complications of RSV hospitalization in elderly populations.”

With an up-to-date model structure that considers current US epidemiology data as well as RSV disease severity, resource utilization, and long-term outcomes, these analyses provide a framework for future RSV evaluations and support the need for a RSV vaccine.

“As progress toward an effective RSV vaccine continues, this analysis provides public health decision makers, researchers, and other stakeholders with contemporary estimates of the population-level burden of RSV disease and fundamental insights into the factors that drive the potential economic value of RSV vaccination,” the authors said.

Reference

Herring WL, Zhang Y, Shinde V, Stoddard J, Talbird SE, Rosen B. Clinical and economic outcomes associated with respiratory syncytial virus vaccination in older adults in the United States. Vaccine. Published online December 20 2021. doi:10.1016/j.vaccine.2021.12.002