A PROBABILISTIC FRAMEWORK FOR COMPARING THE PUBLIC HEALTH IMPACT OF ADJUVANTED RSVPREF3 AND NON-ADJUVANTED RSVPREF VACCINES IN ITALY
Author(s)
Eleftherios Zarkadoulas, MBA, FHAS, CERA1, Federica Piccolo, MSc2, Hiral Anil Shah, BSc, MSc, PhD3, Nidhi Dani, MBA4, Lisa White, PhD3.
1GSK, Wavre, Belgium, 2GSK, Verona, Italy, 3GSK, London, United Kingdom, 4GSK, Zug, Switzerland.
1GSK, Wavre, Belgium, 2GSK, Verona, Italy, 3GSK, London, United Kingdom, 4GSK, Zug, Switzerland.
OBJECTIVES: Respiratory syncytial virus (RSV) remains a substantial cause of morbidity and hospitalization among older adults in Italy. Protein-based and mRNA vaccines are now available for prevention. However, direct comparison of their effectiveness and public health impact is limited by differences in trial design, follow-up duration, and case definitions. Given overlapping evidence with uncertain differentiation, probabilistic modeling using real-world evidence provides a structured approach to assess comparative outcomes. This study aimed to estimate the probability that adjuvanted RSVPreF3 confers greater public health impact than non-adjuvanted RSVPreF in Italy.
METHODS: A probabilistic multi-cohort Markov model was developed to estimate the incremental public health impact over an 18-month time horizon (covering two RSV seasons) among Italy for adults aged 60-74 years at increased risk and adults aged 75+ general population. Vaccine effectiveness inputs were parameterized using probability distributions derived from published confidence intervals and propagated through 1,000 Monte Carlo simulations. Hospitalization outcomes were informed by real-world evidence (IVY Network, VISION Network, Veterans Health Administration target trial emulation). Scenario analyses assessed the robustness of comparative results. Outcomes, which included RSV-related hospitalizations, associated healthcare costs and number needed to vaccinate to avert one hospitalization (NNV).
RESULTS: Adjuvanted RSVPreF3 was more likely than non-adjuvanted RSVPreF to deliver greater public health impact. Across scenarios, 66-79% of simulations favored adjuvanted RSVPreF3, corresponding to incremental avoided hospitalizations from 8.1k to 9.3k versus non-adjuvanted RSVPreF over two RSV seasons. Adjuvanted RSVPreF3 may demonstrate lower NNV, ranging from [113-119] to prevent one hospitalization compared to [127-135] for non-adjuvanted RSVPreF among scenarios.
CONCLUSIONS: According to current real-world evidence and probabilistic modelling analysis, adjuvanted RSVPreF3 is more likely to generate greater public health impact than non-adjuvanted RSVPreF in Italy, reflecting reductions in hospitalizations and associated costs. The framework translates uncertain evidence into decision-relevant insights for payors, patients, and health-care professionals.
METHODS: A probabilistic multi-cohort Markov model was developed to estimate the incremental public health impact over an 18-month time horizon (covering two RSV seasons) among Italy for adults aged 60-74 years at increased risk and adults aged 75+ general population. Vaccine effectiveness inputs were parameterized using probability distributions derived from published confidence intervals and propagated through 1,000 Monte Carlo simulations. Hospitalization outcomes were informed by real-world evidence (IVY Network, VISION Network, Veterans Health Administration target trial emulation). Scenario analyses assessed the robustness of comparative results. Outcomes, which included RSV-related hospitalizations, associated healthcare costs and number needed to vaccinate to avert one hospitalization (NNV).
RESULTS: Adjuvanted RSVPreF3 was more likely than non-adjuvanted RSVPreF to deliver greater public health impact. Across scenarios, 66-79% of simulations favored adjuvanted RSVPreF3, corresponding to incremental avoided hospitalizations from 8.1k to 9.3k versus non-adjuvanted RSVPreF over two RSV seasons. Adjuvanted RSVPreF3 may demonstrate lower NNV, ranging from [113-119] to prevent one hospitalization compared to [127-135] for non-adjuvanted RSVPreF among scenarios.
CONCLUSIONS: According to current real-world evidence and probabilistic modelling analysis, adjuvanted RSVPreF3 is more likely to generate greater public health impact than non-adjuvanted RSVPreF in Italy, reflecting reductions in hospitalizations and associated costs. The framework translates uncertain evidence into decision-relevant insights for payors, patients, and health-care professionals.
Conference/Value in Health Info
2026-11, ISPOR Europe 2026, Vienna, Austria
Value in Health, Volume 29, Issue 12S
Code
EE441
Topic
Economic Evaluation
Topic Subcategory
Cost/Cost of Illness/Resource Use Studies
Disease
Vaccines