 The study compares the immune response of high-dose trivalent inactivated split-virus influenza vaccine IIv3-HD to standard dose trivalent vaccine IIv3-SD in adults aged greater than or equal to 65 years. The results show that IIv3-HD is consistently more immunogenic than IIv3-SD with higher hemid luteination inhibition, HAI, antibody response and similar trends for AH3N2 neutralization and antineuraminidase antibody titers. Additionally, HAI-GMT ratios were mostly one in immunocompromised individuals. This article was offered by Sandrine I. Samsung, Philip S. Levenfall, Camille Salamand, and others.