Abstract / Summary
Background/Objectives: Older adults are at high risk of influenza-related severe disease and complications. HD-IIV, currently recommended for adults [≥]65 years, is egg-based and may be subject to egg-adapted mutations. An mRNA-based vaccine for influenza, mRNA-1010, has been approved by the Food and Drug Administration. Given the clinical benefits observed in mRNA-1010 clinical trials and potential to avoid egg-adapted mutations, this analysis explores the clinical impact of mRNA-1010 compared to HD-IIV in those [≥]65 years in the United States. Methods: This study used a decision-analytic model of influenza infection and downstream outcomes to project influenza burden with each vaccine over a one-year timeframe. Vaccine coverage, HD-IIV vaccine effectiveness (VE) and influenza epidemiology was estimated based upon Centers for Disease Control and Prevention data. The relative VE (rVE) for mRNA-1010 vs. HD-IIV was modelled based on data from the clinical trial and published literature on the impact of egg adaptation. Results: The base-case analysis suggests mRNA-1010 may prevent an additional 232,200 symptomatic influenza infections, 130,000 outpatient cases, 21,100 influenza-related hospitalizations, and 2,200 influenza-related deaths compared to HD-IIV. The number needed to vaccination to prevent one hospitalization was 514 or mRNA-1010 vs no vaccine and 404 for HD-IIV versus no vaccine, for an incremental NNV of 110. Scenario and deterministic sensitivity analyses results indicate that clinical outcomes prevented by mRNA-1010 are most sensitive to influenza incidence and VE. Conclusions: mRNA-1010 may improve protection against influenza in US adults aged [≥]65 years, leading to meaningful reductions in the clinical influenza-related disease burden in older adults.