GnRH Single-Injection Immunocontraception of Black-Tailed Deer

Abstract

High deer densities increase vehicle collisions, damage agricultural crops, and amplify the spread of zoonotic and animal diseases, intensifying human-deer conflict. In addition, deer impact on forest vegetation can influence the distribution and abundance of other wildlife species. Greater demand for non-lethal means of animal damage control has led to an interest in contraception as a wildlife management tool. The development of a single-injection Gonadotropin-Releasing Hormone (GnRH) contraceptive vaccine by NWRC reduces logistical limitations and cost of using immunocontraception as compared to a vaccine that requires two injections. This study assessed the efficacy of two different GnRH-KLH (keyhole limpet hemocyanin) vaccine designs in a single-injection study, to determine if Mycobacterium avium bacterium in the adjuvant is necessary for the success of a single-injection contraceptive vaccine. Forty-two captive female black-tailed deer were divided into 3 groups. Control deer were injected with saline solution, one treatment group received GonaCon ™ (a GnRH-KLH vaccine paired with AdjuVac ™ adjuvant that contains a small quantity of killed M. avium bacterium), and the second treatment group received GnRH-KLH vaccine with DEAE-Dextran/oil as the adjuvant. Contraceptive success was evaluated by monitoring progesterone, pregnancy specific protein, antibodies to GnRH-KLH conjugate and to Johne's bacterium (M. avium), and actual pregnancy rates. Pregnancy rates were significantly different based on treatment (X² = 9.389; df = 2; P = 0.009). Pregnancy rates in deer treated with GonaCon ™ were significantly reduced as compared to saline controls (P = 0.006), but there was no significant difference between GnRH-DD compared to saline (P = 0.297). Significant difference was found between GonaCon ™ and GnRH-DD (P = 0.055). Results suggest that M. avium in the AdjuVac ™ adjuvant is essential for the success of the single-injection GnRH vaccine GonaCon ™ . The development of a single-injection vaccine will increase the practicality and lower the cost of using immunocontraception as a tool to control deer populations.

ORIGINAL ARTICLE: The Single‐Shot GnRH Immunocontraceptive Vaccine (GonaCon™) in White‐Tailed Deer: Comparison of Several GnRH Preparations

“…GonaCon ™ vaccine is a mixture of a new, highly immunogenic antigen (GnRH‐mollusk hemocyanin) with a previously experienced M. avium bacterium. In a GnRH vaccine study with black‐tailed deer ( Odocoileus hemionus columbianus ), Perry et al 43 injected a group of deer with GnRH vaccine in which M. avium had been replaced by DD‐Dextran in the adjuvant. The first‐year response to the DD‐Dextran was 14% contraception ( n = 14).…”

Four-year contraception rates of mares treated with single-injection porcine zona pellucida and GnRH vaccines and intrauterine devices

“…Although the average titre for the non-pregnant SpayVac-treated mares declined in Years 2 and 3 relative to Year 1, the titres actually increased in the fourth year in most of the contracepted mares. This suggests that self boosting of the immune response may occur (Perry et al 2006), perhaps as a result of the seasonality of mare reproduction. It is thought that self boosting occurs in the draining lymph node (Burton et al 1994) as antigen is released from the follicular dendritic cell when the antibody flowing through the draining lymph node drops to a certain level.…”

Efficacy and health effects of a wildlife immunocontraceptive vaccine on fox squirrels

“…Since its development, GonaCon has been used to induce temporary infertility in many mammals, including white‐tailed deer (Miller et al , Gionfriddo et al ), mule deer ( O. hemionus ; Perry et al ), domestic cats ( Felis catus ; Levy et al ), California ground squirrels ( Otospermophilus beecheyi ; Nash et al ), Norway rats ( Rattus norvegicus ; Miller et al ), feral pigs ( Sus scrofa ; Killian et al ), eastern gray squirrels ( Sciurus carolinensis ; Pai ), and black‐tailed prairie dogs ( Cynomys ludovicianus ; Yoder and Miller ). Although the safety and efficacy of GonaCon have been documented in a variety of species, less is known about the types and severity of side effects.…”