Agents and procedures for provoking an immune response to gnrh and

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which is common to all mammals except that one or more of the normally occurring amino acids of this decapeptide have been replaced by an amino acid with a more reactive side group.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. The vaccine formulation is then administered in a manner which raises a substantial amount of antibodies which bind to native GnRH. Injection in a manner which provides a slow release to the circulatory system such as IP, IM or SC is favored.