Comparison of Immunogenicity of Adjuvanted and Non-Adjuvanted Influenza Vaccination in a Long-Term Care Population

Summary: Study investigators will recruit residents of nursing homes that are administering a licensed influenza vaccine as their standard or care, either the trivalent influenza vaccine (Fluvirin) or the adjuvanted trivalent influenza vaccine (Fluad). Eligible residents are those or their legally authorized representatives who give written, informed consent for three blood draws over one month's time and permission to review their nursing home medical and administrative records, including information required to be submitted to Medicare including quality performance data (the Minimum Dataset or MDS) and Medicare claims data for demographic and underlying disease comparisons between our participating populations between nursing homes. The investigators propose to study up to 230 subjects in one season at a 1:1 ratio of adjuvanted vs. and non-adjuvanted vaccine.

Background: Influenza is the most common clinically important viral infection of older adults. Influenza vaccination is associated with reduced hospitalization, strokes, heart attacks and death in non-institutional older adult populations, but the benefit of influenza vaccine for the oldest population has been questioned. The adjuvanted vaccine was shown in the past to elicit higher antibody titers than non-adjuvanted TIV. This included the elderly population as well. There are far more limited data about cell-mediated immunity (CMI) and use of the adjuvanted vaccine. There are data that support that CMI is important beyond the helper function to B cells. CMI helps mitigate influenza disease if the antibodies alone are not adequately protective.

Objectives: To determine if adjuvanted vaccine elicits higher T cell and B cell responses than non-adjuvanted standard dose influenza vaccine in nursing home residents.