The Potential Public Health Impact of the Adjuvanted Respiratory Syncytial Virus Prefusion F Protein Vaccine Among Older Adults in Italy.

Background: Respiratory syncytial virus (RSV) is a common cause of acute respiratory infection (ARI). The risk of severe RSV outcomes is higher among older adults (OAs) and individuals with chronic diseases (high risk, HR). AS01E-adjuvanted RSV preFusion protein 3 OA vaccine (adjuvanted RSVPreF3 OA is approved for the prevention of lower respiratory tract disease [LRTD] due to RSV in OAs). The objective of this study was to assess the potential public health impact of an RSV vaccination program using adjuvanted RSVPreF3 OA in adults ≥75 years (y) and HR adults ≥60 y in Italy.

Methods: A static multi-cohort Markov model was used to estimate the number of RSV cases and associated health outcomes projected in adults ≥75 y and HR adults ≥60 y with no RSV vaccination or with a single dose of adjuvanted RSVPreF3 OA. Epidemiological, healthcare resource use and cost data were obtained from the scientific literature. Vaccine efficacy and waning inputs were based on results from the AReSVi-006 phase III clinical trial. Several scenarios for vaccine coverage were explored.

Results: Assuming the target vaccination rate for influenza vaccination in Italy (75%), the model predicted that vaccinating Italian adults ≥75 y and the HR population ≥ 60 y with adjuvanted RSVPreF3 OA would reduce the number of RSV-LRTD events by 43%, leading to a reduction in associated emergency department visits, hospitalizations, complications, deaths, and direct healthcare costs over a 3-year period.

Conclusions: The vaccination of Italians aged ≥ 75 y and HR individuals aged ≥ 60 y using the adjuvanted RSVPreF3 OA vaccine has the potential to offer substantial public health benefits by reducing the burden of RSV disease.