DEVELOPMENT OF CONTRACEPTIVE VACCINES FOR HUMANS USING ANTIGENS DERIVED FROM GAMETES (SPERMATOZOA AND ZONA-PELLUCIDA) AND HORMONES (HUMAN CHORIONIC-GONADOTROPIN) - CURRENT STATUS

Contraceptive research has entered a new phase of development with the advent of hybridoma and DNA recombinant technologies. During the past 5 years, significant advances have been made in this area and now it seems that realistic prospects exist for the development of contracept ive vaccines for use in humans and animals (veterinary, wild and domes tic), applicable to both the female and male sexes. Contraceptive vacc ines will be valuable supplements to the presently available methods o f family planning, and, due to high specificity, the occurrence of lim ited side-effects if any, low cost and infrequent administration, cont raceptive vaccines may have greater acceptability than the currently a vailable methods. Mammalian reproduction starts with the unison of gam etes contributed by the male and female partners. Both spermatozoon an d oocyte have antigens on the cell surface that are unique, tissue-spe cific, immunogenic and accessible to antibodies, and binding of the an tibodies to these antigens can cause inhibition of gamete function, re sulting in a failure of fertilization. Fertilization is followed by em bryogenesis, with the early embryo producing several proteins, some of which, e.g. human chorionic gonadotrophin (HCG), have a vital role in the establishment and maintenance of early pregnancy. Again, these pr oteins are accessible to antibodies, and their immunoneutralization ca n cause anti-fertility effects with loss of early embryo. Thus, the an tigens derived from proteins on spermatozoa, oocyte and early embryo, especially HCG, constitute interesting molecules for the development o f contraceptive vaccines. The aim of the present article is to review the current status of development of contraceptive vaccines based on a ntigens derived from sperm cell, oocyte zona pellucida and HCG, and to discuss their relative merits and future development.