A Core will be established to support investigations on human subjects in the three research projects. This Clinical Subjects and Recruitment Core will provide a centralized resource for subject recruitment, screening and enrollment. Project 1 will employ a pre-existing network of clinical sites developed by co-PI Bockenstedt in Connecticut, including the Yale-New Haven Health System, and in Portland, Maine and Mansfield, CT for recruitment of participants with Lyme Disease. Project 2 recruitment will be carried out by collaborators in Texas (for West Nile Virus (WNV) infection), but will also include participants in Connecticut with WNV disease. Project 3 will utilize already-collected samples from a previously enrolled cohort; in addition, young (age 21- 30), non-frail and frail older (age ≥70) adults will be enrolled for a study of the high-dose influenza vaccine based in New Haven, Connecticut. This Core will also be responsible for ensure safety and information security for all participants and for compliance with all regulatory measures. The Core will be responsible for maintaining and deploying our established barcoding sample system for generation of subject numbers, tracking of samples, and mapping to external IDs, collaborating with Core B (Data Management and Analysis), where data management platforms are based. The Core is led by investigators with extensive experience carrying out human immunology studies who have the necessary regulatory and clinical experience. Consequently, this Clinical Subjects and Recruitment Core will advance the goals of this Human Immunology Project Consortium application.