Phase i clinical trial of a World Health Organisation birth control vaccine
Jones, W.R.; Bradley, J.; Judd, S.J.; Denholm, E.H.; Ing, R.M.; Mueller, U.W.; Powell, J.; Griffin, P.D.; Stevens, V.C.
Lancet 1(8598): 1295-1298
1988
ISSN/ISBN: 0140-6736 PMID: 2453766 DOI: 10.1016/s0140-6736(88)92117-4Document Number: 359872
A Phase I clinical trial of the immunogenicity and safety of a vaccine against the C-terminal region of the beta subunit of human chorionic gonadotropin (hCG-B) demonstrated a dose-related immune response. The antigen was a synthetic peptide of the C 109-145 region of hCG-B, conjugated to diphtheria toxoid, and administered in a water-soluble synthetic adjuvant in a saline-oil emulsion. This vaccine had been previously tested for toxicity in laboratory animals and for immunogenicity, safety and contraceptive effectiveness in baboons. 30 previously sterilized women were given 2 injections 6 weeks apart, ranging from 50 to 1000 mcg of the antigen. Each woman tested free of HLA B27 antigen and reacted negative to the diphtheria toxoid skin test. Based on calculated contraceptive antibody binding level of 0.52 nmol/l, all subjects mounted an effective antibody response for at least 6 months. 2 subjects in the group given 1000 mcg who were followed for 9 and 10 months maintained this level of antibody. 12 women showed an anamnestic response to diphtheria toxoid, while 8 did not. The only adverse reactions were mild, transient pain at the injection site. Several women who received unstable adjuvant experienced more severe myalgia. Menstrual changes appeared in 5 subjects: early menopause in 1, spotting in 3 and menorrhagia in 1 woman. Only transient positive findings were seen in some sera screened for autoantibodies. This preliminary trial indicates that anti-hCG vaccine is a hopeful reversible contraceptive.