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.