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An alternative to surgical sterilization for fertility control of animals (wild, zoo, farm, and domestic) is needed to prevent problems related to overpopulation, including culling and relocation. A PubMed and Google Scholar database search was conducted using the keywords 'contraceptive vaccine animals,' 'immunocontraception animals,' 'non-surgical sterilization animals,' 'PZP vaccine,' and 'GnRH vaccine.' The searches from 1972 to 2015 yielded over 1500 publications. These articles were read, and 375 were selected for detailed analysis. Articles referenced in these publications were also thoroughly examined. PZP and GnRH contraceptive vaccines (CVs) have been extensively investigated for fertility control of wild, zoo, farm, and domestic animal populations. Both vaccines have shown tremendous success with PZP vaccines taking the lead. Novel technologies and targets are being developed to improve existing vaccines and generate second-generation CVs. Single-shot vaccines, which can be delivered remotely, will greatly advance the field of immunocontraception for animal use with potential human application., (© 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

The year 2011 marks the 84th year of the discovery of human chorionic gonadotropin (hCG) by Ascheim and Zondek. Originally considered and employed as a reliable diagnostic index for pregnancy, the multiple roles of hCG as an initiator and sustainer of pregnancy are now recognized. Besides pregnancy, the expression of hCG or its subunits is observed in a number of cancers of diverse type, in particular at advanced stage. Cancers expressing hCG/subunits have poor prognosis and adverse survival. Thus, immunological approaches against hCG have applications for control of fertility and for treatment of terminal cancers. Various mechanisms by which hCG exercises its action are discussed. These include its role as autocrine growth promoter, inhibitor of apoptosis, promotor of angiogenesis, invasiveness, and protection against rejection by the immune system. The article reviews various vaccines developed for control of fertility and for therapy of advanced-stage cancers expressing ectopically hCG/subunits. Also reviewed are the recombinant fully humanized and chimeric antibodies usable for emergency contraception, as vacation contraceptive, and as therapeutic antibodies for treatment of cancers., (© 2011 John Wiley & Sons A/S.)

Current methods of contraception lack specificity and are accompanied with serious side effects. A more specific method of contraception is needed. Contraceptive vaccines can provide most, if not all, the desired characteristics of an ideal contraceptive. This article reviews several factors involved in the establishment of pregnancy, focusing on those that are essential for successful implantation. Factors that are both essential and pregnancy-specific can provide potential targets for contraception. Using database search, 76 factors (cytokines/chemokines/growth factors/others) were identified that are involved in various steps of the establishment of pregnancy. Among these factors, three, namely chorionic gonadotropin (CG), leukemia inhibitory factor (LIF), and pre-implantation factor (PIF), are found to be unique and exciting molecules. Human CG is a well-known pregnancy-specific protein that has undergone phase I and phase II clinical trials, in women, as a contraceptive vaccine with encouraging results. LIF and PIF are pregnancy-specific and essential for successful implantation. These molecules are intriguing and may provide viable targets for immunocontraception. A multiepitope vaccine combining factors/antigens involved in various steps of the fertilization cascade and pregnancy establishment may provide a highly immunogenic and efficacious modality for contraception in humans., (© 2011 John Wiley & Sons A/S.)

This is a review of current status and future perspectives on the development of antisperm contraceptive vaccines (CV) and immunocontraceptives. The development of antisperm CV is an exciting proposition. There is a strong rationale and recent data indicating that this proposition can translate into reality. The search for novel sperm-specific antigens/genes, that can be used for CV, continues using various recent developing technologies. Various approaches of proteomics, genomics, reproductive biology, mucosal immunity and vaccinology and several novel technologies such as gene knockout technology, phage display technology, antibody engineering, differential display technique, subtractive hybridization, and hybridoma technology are being used to delineate sperm-specific antigens and construct CV. Various sperm antigens/genes have been delineated, cloned, and sequenced from various laboratories. Vaccination with these sperm antigens (recombinant/synthetic peptide/DNA) causes a reversible contraceptive effect in females and males of various animal species, by inducing a systemic and local antisperm antibody response. The efficacy is enhanced by combination vaccination, including peptides based on various sperm antigens. Several human novel scFv antibodies with unique complementarity-determining regions (CDRs), that react with specific well-defined fertility-related sperm antigens, have been synthesized. These human infertility-related antibodies may find application in the development of novel immunocontraceptives. Besides finding the novel sperm antigens, the present and future focus is on enhancing the immunogenicity, bioefficacy, and on obliterating the inter-individual variability of the immune response, and proceeding for primate and human clinical trials. Multi-epitope vaccines combining sperm proteins involved in various steps of fertilization cascade have been found to enhance the immunogenicity and bioefficacy of the contraceptive effect. The in vitro synthesis of infertility-related human scFv antibodies may provide unique once-a-month immunocontraceptives, the first of its kind, for human use. The multi-epitope CV and preformed engineered human antibodies of defined specificity may obliterate the concern related to inter-individual variability of the immune response., (© 2011 John Wiley & Sons A/S.)