1435. The Cost-Effectiveness of Vaccinating With an Adjuvanted Trivalent Influenza Vaccine for the 65+ Population in Argentina

BACKGROUND: Despite the current vaccination program in Argentina for older adults (OA), influenza continues to have severe consequences. Estimates based on Argentinian information surveillance system suggest that influenza-like illness reaches an average rate of 3,570/100,000 annually, a hospitalization rate of 15.5/100,000 and a death rate of 0.32/100,000 in OA aged 65+. The high burden of disease in this population is in part due to immunosenescence and the resulting suboptimal clinical effectiveness of influenza vaccines in this age group. There is an unmet clinical need in those aged 65+ for an influenza vaccine that offers enhanced protection. The objective of this study was to evaluate the cost effectiveness (CE) of the MF59 adjuvanted vaccine (aTIV) in Argentina compared with current vaccination policy with an un-adjuvanted vaccine (TIV). METHODS: A static decision tree CE model of aTIV was developed to estimate the cost effectiveness compared with TIV vaccine in those aged 65+ in Argentina. The model compares cost and health benefits of vaccination in an influenza season from the payer and the societal perspective. The main outcomes include events, death, LLY, QALYs, and costs. To the extent possible, model inputs were sourced from Argentina; in cases where local data were insufficient, international inputs were utilized. Vaccine efficacy assumptions were extracted from recent literature search. RESULTS: Using aTIV instead of TIV resulted in additional 530 deaths averted and 3,980 incremental quality-adjusted life-years (QALYs) gained. The incremental cost-effectiveness ratio (ICER) was US$243 and US$937 per QALY from societal and payer′s perspective respectively. In all univariate sensitivity analyses, aTIV remained highly cost-effective meeting the threshold of one GDP per capita in Argentina. From a societal perspective, the probabilistic sensitivity analyses showed aTIV cost-saving in 30% of the simulations. CONCLUSION: This analysis suggests that vaccinating with aTIV in Argentina would be a highly cost-effective in providing additional health gains while reducing healthcare resources utilization and costs. DISCLOSURES: N. Giglio, Sanofi Pasteur: Consultant, Speaker honorarium.