Immunocontraception of mammalian wildlife: ecological and immunogenetic issues

Abstract

Immunocontraception involves stimulating immune responses against gametes or reproductive hormones thus preventing conception. The method is being developed for the humane control of pest and overabundant populations of mammalian wildlife. This paper examines three fundamental issues associated with its use: (1) the difficulties of obtaining responses to self-antigens, (2) the likely evolution of genetically based non-response to immunocontraceptive agents, and (3) the possible changes in the array of pathogens possessed by the target species after generations of immunocontraception. Our review of the literature demonstrates that the barriers to an effective immunocontraceptive are at present very basic. Should they be overcome, the effects of immunocontraception on the immunogenetic constitution of wildlife populations through the selection for nonresponders must be examined. We suggest that the attempt to use the animal's own immune system to modulate reproduction may be incompatible with the basic biological function of protection against infectious disease. Research programs on mammalian immunocontraception should involve measurement of the heritability of non-response and an assessment of the likely change in the response of the contracepted population to possible pathogens.

Fertility control to mitigate human–wildlife conflicts: a review

“…Gross 2000;Magiafoglou et al 2003;Holland et al 2009). Although some studies concluded that the evolution of resistance was unlikely (Magiafoglou et al 2003), research programs on mammalian immunocontraception should involve measurement of the heritability of non-response (Cooper and Larsen 2006). For instance, in brushtail possums, two sets of alleles (haplotypes) were found to associate significantly with differences in response to immunocontraceptive vaccines (Holland et al 2009).…”

“…With the exception of the overview by Fagerstone et al (2010) on issues concerning the use of reproductive inhibitors for wildlife in North America, these reviews have focussed on specific groups such as zoo species and companion animals (Asa and Porton 2005;Munson 2006;Purswell and Kolster 2006;Levy 2011;Massei and Miller 2013), on particular compounds such as immunocontraceptives (Cooper and Larsen 2006;Kirkpatrick et al 2011), on selected species such as brushtail possums (Trichosurus vulpecula) (Ji 2009;Cross et al 2011) or on groups of species such as ungulates (Patton et al 2007). Here, we provide a comprehensive, critical overview of fertility control to mitigate human-wildlife conflicts, with the following aims:…”

Does contraceptive treatment in wildlife result in side effects? A review of quantitative and anecdotal evidence

“…Nettles (1997) reviewed potential side effects, which included physiological effects, behavioral effects, population impacts and evolutionary impacts, and more recently suggested side effects include evolutionary effects (Magiafoglou et al 2003, Cooper & Larsen 2006 and impacts on disease transmission rates (Tuyttens & MacDonald 1998, Caley & Ramsey 2001, Miller et al 2004. The diversity of contraceptive agents means that there is potential for a variety of secondary impacts.…”

Vesicle-associated protein 1: a novel ovarian immunocontraceptive target in the common brushtail possum, Trichosurus vulpecula

“…Contraceptive vaccines may interfere with gamete production, fertilization, or embryogenesis by stimulating an immune reaction to key reproductive molecules. Common targets of interest include proteins of the zona pellucida (Barber & Fayrer-Hosken 2000), sperm surface antigens, and reproductive hormones (Naz et al 2005, Cooper & Larsen 2006, Hardy & Braid 2007.…”