116. Potential Clinical Impact of Respiratory Syncytial Virus (RSV) Vaccination in Older Adults in the United States


 
 
 RSV causes acute respiratory disease (ARD), including severe lower respiratory tract disease (LRTD) in older adults, which can lead to hospitalization and death. Currently, there are no vaccines approved to prevent RSV disease. This study estimated the potential clinical impact of a hypothetical RSV vaccine over a 1-year time horizon in older adults aged ≥ 60 years.
 
 
 
 A decision-analytic model was developed (Figure 1). A strategy was used where the entire US population aged ≥ 60 years was given a single dose vaccine with an assumed efficacy of 75% against ARD, LRTD, and LRTD-hospitalizations and compared to a population who did not receive a vaccine. Given the uncertainty around RSV hospitalization rates, 2 base-case scenarios were created: (1) hospitalization rates that used RSV-specific claim codes and (2) hospitalization rates increased by 49% to account for underreporting in claims; Table 1 shows key inputs. One-way sensitivity analyses were used to assess the impact of specific parameter estimates.
 
 
 
 The vaccine would prevent 1.8 million and 0.6 million upper respiratory disease and LRTD cases, respectively; Figure 2 shows additional results for both base-case scenarios. The number needed to vaccinate (NNV) to prevent 1 LRTD case is 119; the NNV to prevent 1 LRTD hospitalization or death ranges from 792 to 1180 and 10,452 to 15,574, respectively. Sensitivity analyses indicate that results mainly depend on vaccine efficacy, and incidence of ARD and LRTD.
 
 
 
 There is substantial US public health benefit associated with utilization of an effective RSV vaccine in individuals ≥ 60 years of age to reduce RSV-associated morbidity and mortality; however, the magnitude of impact depends on RSV epidemiology, which is still being defined for older adults. Several model parameters were based on assumptions, and robust evidence generation is needed including the efficacy of an RSV vaccine, which is an important consideration in assessing the impact of vaccination in this age group.
 
 
 
 Kelly Fust, MS, Quadrant Health Economics Inc: Contractor at Quadrant Health Economics Inc who was funded by Moderna to perform this study Michele Kohli, PhD, Quadrant Health Economics Inc: Shareholder at Quadrant Health Economics Inc who was funded by Moderna to perform this study|Quadrant Health Economics Inc: Stocks/Bonds Catherine A. Panozzo, PhD, Moderna, Inc.: Salary|Moderna, Inc.: Stocks/Bonds Philip Buck, PhD, MPH, Moderna, Inc.: Salary|Moderna, Inc.: Stocks/Bonds Parinaz Ghaswalla, PhD, Moderna, Inc.: Salary|Moderna, Inc.: Stocks/Bonds.
