Progress in immunological fertility control
Thanavala, Y.
Ippf Medical Bulletin 15(3): 2-3
1981
ISSN/ISBN: 0019-0357 PMID: 12278629 Document Number: 173994
A variety of contraceptive methods is required, for 1 method simply does not meet the requirements of a population that is adopting practices of fertility regulation. None of the existing methods is absolutely safe, free of all side-effects, and universally acceptable. On this basis alone, further research and alternative contraceptive methods is justified. A mode of contraception requiring only periodic administration would make a significant impact in countries faced with rampant population growth. The question that arises against this background is whether immunological methods have any special place in a program of fertility control. Attention is directed to immunization against human chorionic gonadotropin (hCG), the problem of reaction with the luteinizing hormone (LH), and bypassing LH. A major problem in a program involving immunization with hCG is that the chemical structure of this hormone is similar to the glycoprotein hormone produced by the pituitary--LH. Both these hormones are made up of 2 dissimilar subunits designated alpha beta, and held together by non-covalent bonds. The alpha subunits of hCG and LH cannot be distinguished. Of the initial 115 amino acid residues in the beta subunit of hLH, at least 80 are identical with those found in beta hCG. The carboxyl (COOH) terminal end of beta hCG has an additional 30 amino acids constituting a unique polypeptide sequence not present in hLH. All effort is currently being directed towards developing a vaccine against hCG on antigens derived from the COOH-terminal end of beta hCG.