Antibody response to Pr-β -HCG-TT vaccine in human subjects

Abstract

The ability of Pr-β -HCG-TT vaccine to elicit anti-HCG antibodies have been investigated in four human subjects who were in reproductive age and of proven fertility. All subjects responsed positively by formation of anti-HCG and anti-tetanus toxoid antibodies. The anti-HCG antibodies were detectable after a lag period of 6 to 8 weeks and plateau levels were attained at about five months after primary immunization with the vaccine. The anti-HCG antibody titers though declining were still high in three subjects after nearly 11 months of immunization. In one of the subjects the titers declined to near zero levels after 16 months indicating the reversibility of antibody response with this vaccine. The antibodies reacted immunologically with the whole HCG molecule and were competent to neutralize the biological activity of HCG in radioligand receptor assay.