The single-shot GnRH immunocontraceptive vaccine (GonaCon) in white-tailed deer: comparison of several GnRH preparations.

PROBLEM An effective, single-injection, multi-year, GnRH contraceptive agent is needed to control reproduction in overabundant white-tailed deer populations. METHOD OF STUDY Two GnRH conjugates, GonaCon (GnRH-KLH) and GonaCon-B (GnRH-blue protein), were prepared in emulsion form as one-injection and two-injection immunocontraceptive vaccine formulations. In addition, the GnRH-KLH protein conjugate was lyophilized and suspended in AdjuVac adjuvant to produce a fifth vaccine formulation. Each formulation was administered to a group of five captive adult female white-tailed deer. Reproductive performance of treated female deer was monitored for 5 years to determine the comparative efficacy of the various treatments. RESULTS The longevity of the contraceptive response (2-5 years) was strongly influenced by the design of the conjugate antigen, the adjuvant used, and the delivery form of the vaccine. CONCLUSION One-injection and two-injection formulations of GonaCon and GonaCon-B produced multi-year contraception in adult female white-tailed deer. GonaCon-B provided a longer lasting contraceptive effect.