The Lyme Research Alliance, Inc. recently awarded Dr. Nicole Baumgarth a grant to study “Host Defense Against Borrelia burgdorferi Infection”.  The proposed project is concerned with identifying CD4 T cell epitopes on three antigens of Borrelia burgdorferi, that they showed previously to give strong T-dependent IgG responses after infection of C57BL/6 mice with B. burgdorferi.  Our studies could explain the clinically observed rapid decline of antibodies in the serum of infected and antibiotic-treated patients, the frequent repeat infections in endemic areas, and possibly also the often-observed co-infections with other tick-borne illnesses.