CSL(US:CSLLY) Prnewswire·2025-10-21 12:30Core Insights - CSL Seqirus has announced that cell-based influenza vaccines provide greater protection against test-confirmed influenza compared to standard egg-based vaccines for individuals aged six months to 64 years [1][5][10]. Study Overview - A retrospective test-negative study was conducted to evaluate the relative vaccine effectiveness (rVE) of cell-based influenza vaccines versus egg-based vaccines during the U.S. 2023/24 influenza season [3][12]. - The study analyzed data from 106,779 vaccinated and influenza-tested patients, including various subgroups such as pediatric, adult, outpatient, and high-risk populations [4][10]. Key Findings - The study found an estimated rVE of 19.8% (95% CI; 15.7 – 23.8%) for cell-based vaccines compared to egg-based vaccines in preventing test-confirmed influenza [5][10]. - Consistent rVE results were observed across different age subgroups and at-risk populations, indicating robust effectiveness [5][10]. Clinical Implications - The findings suggest that if all vaccinated individuals aged six months to 64 years had received cell-based vaccines, an estimated 14,930 hospitalizations could have been prevented during the 2023/24 influenza season [6][10]. - The study adds to a growing body of evidence supporting the clinical benefits of cell-based vaccines over traditional egg-based options [7][10]. Manufacturing and Technology - CSL Seqirus operates the largest cell-based influenza vaccine manufacturing facility in the world, located in Holly Springs, North Carolina, which supports global vaccine distribution [11][15]. - Cell-based technology allows for a more accurate antigenic match to the vaccine strain selected by the World Health Organization, enhancing vaccine effectiveness [8][9].