Vaccines for feline contraception: GonaCon GnRH-hemocyanin conjugate immunocontraceptive

Vaccine: GonaCon is the trade name of a GnRH-hemocyanin conjugate immunocontraceptive vaccine formulation shown to prevent reproduction and inhibit production of sex hormones in numerous mammalian species for extended durations. GonaCon is currently registered with the US Environmental Protection Agency (EPA) for contraception of female white-tailed deer, and GonaCon-Equine for female wild horses and burros. Multiple formulations of this GnRH-hemocyanin conjugate immunocontraceptive vaccine have been developed at the National Wildlife Research Center in the United States. Evidence base: Three studies employing an early generation vaccine formulation indicated its potential for multi-year contraception of female cats (median duration of effect in excess of 39.7 months). The contraceptive effect for male cats was less predictable and of shorter duration (median duration of effect 14 months). Since these initial feline studies there have been formulation composition changes, and further investigation of the safety, efficacy and duration of this contraceptive vaccine for cats is warranted. Future prospects: Individual country regulations will determine if GonaCon could be registered for unowned, free-roaming and/or pet cats.