OBJECTIVES: Respiratory syncytial virus (RSV) is a common cause of acute respiratory infections, and the risk of severe RSV outcomes is higher among older adults (OA) and individuals with chronic diseases (high risk, HR). The AS01E-adjuvanted RSV prefusion F OA vaccine (adjuvanted RSVPreF3) is indicated for the prevention of lower respiratory tract disease (LRTD) due to RSV in adults ≥60 years (y). Objective of this study is to assess the potential public health impact of an RSV vaccination program using adjuvanted RSVPreF3 vaccine among OA ≥75y and HR adults ≥60y (≥60y HR) in Italy.

METHODS: A static multi-cohort Markov model with a three-year time horizon, representing three RSV seasons, was used to estimate the public health impact of the adjuvanted RSVPreF3 vaccine, in comparison with no vaccination, in OA ≥75y and adults ≥60y HR in Italy. Demographic, epidemiologic, and cost data were derived from National databases and scientific literature. Vaccine efficacy and waning inputs were based on results from AReSVi-006 Phase III clinical trial. In the base-case analysis, target influenza vaccine coverage rate of 75% was assumed.

RESULTS: In the base case analysis, compared to no vaccination, the adjuvanted RSVPreF3 vaccine targeting OA ≥75y and adults ≥60y HR would reduce the number of RSV-LRTD events by 43%, leading to a reduction of associated emergency department visits, hospitalizations, complications (i.e., pneumonia cases), deaths and direct healthcare costs over a three -year period.

CONCLUSIONS: A vaccination program using one dose of the adjuvanted RSVPreF3 vaccine in the population ≥75y and ≥60y HR, offers the potential for substantial reductions of disease burden associated with RSV in and HR OA in Italy, and potential reductions in direct costs for the Italian National Health Service. These findings may be helpful to support policymakers and clinicians in making decisions about RSV vaccination in Italy.