Estimated rates of influenza-associated hospitalization and death are generally highest among individuals 65 years of age and older (1-4), an age group for whom influenza vaccine effectiveness is often lower relative to younger populations (5, 6). Two inactivated influenza vaccines approved in the U.S. for persons aged ≥65 years have features intended to promote a better immune response for this age group. These include a high-dose inactivated influenza vaccine containing four times the antigen dosage per virus compared with standard dose inactivated vaccines (approved as a trivalent formulation [HD-IIV3] in 2009 and a quadrivalent formulation [HD-IIV4] in 2019), and an inactivated vaccine containing the adjuvant agent MF59 (approved as a trivalent formulation [aIIV3] in 2015 and a quadrivalent formulation [aIIV4] in 2020). These two vaccines, as well as a recombinant influenza vaccine containing three times the antigen dosage per virus compared with SD-IIVs (initially licensed as a trivalent formulation [RIV3] in 2013 and as a quadrivalent [RIV4] in 2016 and approved for ages ≥18 years), have been evaluated for relative efficacy and effectiveness compared with standard dose unadjuvanted inactivated influenza vaccines (SD-IIVs) among older adults (7-9). This assessment sought to review the available published evidence for relative efficacy, effectiveness, and safety of HD-IIV, aIIV, and RIV to support ACIP discussion of whether any one or more of these three vaccines should be preferentially recommended over other age-appropriate influenza vaccines (unadjuvanted SD-IIVs) for persons ages 65 years and older.