Late Breaking Abstract - Public health impact of adjuvanted RSVPreF3 vaccination of older adults in six Latin American countries

<bold>Aims and objectives:</bold> In Latin America, data for Respiratory syncytial virus (RSV) disease burden in older adults ≥60 years (OA) are limited. We aimed to estimate the RSV burden and impact of adjuvanted RSV prefusion F protein vaccine (RSVPreF3) vaccination in OA in 6 countries; Argentina, Brazil, Chile, Colombia, Mexico, Panama. <bold>Methods:</bold> A static multi-cohort Markov model was used to estimate RSV-related outcomes over a 3-year time horizon, evaluating scenarios without and with RSVPreF3 vaccination (exploring 30% and 70% coverage). Outcomes included symptomatic RSV acute respiratory illness (RSV-ARI), classified as upper or lower respiratory tract disease (URTD/LRTD), and RSV-LRTD hospitalizations and mortality. Model inputs were sourced from published data and the pivotal AReSVi-006 study. <bold>Results:</bold> Without vaccination, across all 6 countries the model estimated over 13.8 million symptomatic RSV-ARI cases (7.2 million RSV-URTD and almost 6.6 million RSV-LRTD) in OA over 3 years. Of these, 549,535 were hospitalized due to LRTD, with 52,169 LRTD-deaths. RSVPreF3 vaccination (30% coverage) was estimated to result in 1.6 million fewer RSV-ARI cases, and avoid 89,794 hospitalizations and 8,524 deaths. Data per country and impact with 70% coverage are shown in Figure 1. <bold>Conclusions:</bold> RSV burden in OA is estimated to be substantial and adjuvanted RSVPreF3 vaccination offers considerable benefits for Latin America. <bold>Funding:</bold> GSK <fig><object-id>erj;64/suppl_68/OA3677/F1</object-id><object-id>F1</object-id><object-id>F1</object-id><graphic></graphic></fig>