Abstract: A technique has been developed to cause a mammal to generate antibodies which will bind to its native GnRH thus suppressing the mammal's fertility. The technique involves vaccinating a mammal with a novel conjugate of an immuno stimulating carrier and a novel GnRH analogue. The analogue is substantially identical to the natural GnRH which is common to all mammals except that one or more of the normally occurring amino acids of this decapeptide have been replaced by an amino acid with a more reactive side group. A favored technique is to utilize an analogue containing cysteine which, of course, has as a sulfhydryl side group. This analogue may then be conjugated to a large protein carrier using a heterobifunctional agent carrying a group reactive with carboxyl or amino groups and a group reactive with sulfhydryl groups. This conjugate then forms the immunogen base for a vaccine which may also contain art recognized adjuvants.

Abstract: A monoclonal antibody against GnRH and particularly designated USASK/DSIL-GnRH is produced by a hybrid formed by fusion of cells from a myeloma line and antibody producing cells of the immune system from an animal previously immunized with a source of GnRH; the monoclonal antibody has the following characteristics:(i) it produces a short term reduced mean level of luteinizing hormone (LH) in immunized mammals;(ii) it produces a short term reduced pulsatile secretion of LH in immunized mammals;(iii) it terminates pregnancy in a female mammal with an accompanying decline in progesterone levels;(iv) it produces a long term reduced testosterone level in a male mammal, and,(v) it induces inferility in a male mammal;thus passive immunization of the female or male with the monoclonal antibodies may be employed to reduce fertility and terminate pregnancy.

Abstract: A monoclonal antibody against GnRH and particularly designated USASK/DSIL-GnRH is produced by a hybrid formed by fusion of cells from a myeloma line and antibody producing cells of the immune system from an animal previously immunized with a source of GnRH; the monoclonal antibody has the following characteristics:(i) it produces a short term reduced means level of luteinizing hormone (LH) in immunized mammals;(ii) it produces a short term reduced pulsatile secretion of LH in immunized mammals;(iii) it terminates pregnancy in a female mammal with an accompanying decline in progesterone levels;(iv) it produces a long term reduced testosterone level in a male mammal, and(v) it induces infertility in a male mammal; thus passive immunization of the female or male with the monoclonal antibodies may be employed to reduce fertility and terminate pregnancy.