Human Chorionic Gonadotropin is an Ideal Target for Immuno-Contraception, Development of a Potential Birth Control Vaccine with Additional use for Immunotherapy of Advanced Stage Cancers

Special Article - Human Chorionic Gonadotropin

Austin J Obstet Gynecol. 2016; 3(2): 1059.

Human Chorionic Gonadotropin is an Ideal Target for Immuno-Contraception, Development of a Potential Birth Control Vaccine with Additional use for Immunotherapy of Advanced Stage Cancers

Talwar GP¹*, Gupta JC¹, Hada RS¹, Nand KN¹, Vyas SP², Vyas HK³ and Rulli SB4

¹Talwar Research Foundation, New Delhi, India

²Alpha Diagnostic International Inc, San Antonio, TX, USA

³Department of Virology and Immunology, Texas Biomedical Research Institute, TX, USA

4Instituto de Biologia y Medicina Experimental CONICET Buenos Aires Argentina, Argentina

*Corresponding author: Talwar GP, Director Research, Talwar Research Foundation, E-8, Neb Valley, Neb Sarai, New Delhi, India

Received: September 08, 2016; Accepted: October 03, 2016; Published: October 06, 2016


The making of initial and progressively better, more immunogenic vaccines against hCG is briefly reviewed. Phase I Clinical trials in India, Finland, Sweden, Chile and Brazil have shown the safety and reversibility of the vaccine. Phase II trials have shown that anti-hCG antibodies above 50ng/ ml titres prevent pregnancy in sexually active women without impairment of ovulation and derangement of menstrual regularity. A recombinant anti-hCG has been developed, which is expressed as DNA and protein. Priming with DNA followed by proteinic boosters of the vaccine induces very high titres of antihCG antibodies in mice. Extensive toxicology studies in rodent and marmosets have shown the safety of the recombinant vaccine. Besides contraception, the vaccine may find applications in therapy of terminal drugs-resistant cancers expressing hCG ectopically.

Keywords: Prevention of pregnancy; Ectopic expression of hCG in cancers


Human Chorionic Gonadotropin (HCG) is a highly interesting hormone. It is not made or secreted in any meaningful quantity by any organ of a non-pregnant healthy female that is why its appearance in urine or blood is a world-wide used test for diagnosis of pregnancy. It only emerges after fertilization of the egg. The early embryo makes it, an observation [1] which won Bob Edwards a Nobel Prize. HCG plays a crucial role in implantation of the embryo onto the endometrium leading to the onset of pregnancy. Marmoset embryos exposed to anti-hCG antibodies fail to implant, whereas the same embryos exposed to irrelevant immunoglobulins implant perfectly [2]. It is vital to the sustenance of pregnancy. Many years back when I thought of making a possible vaccine for control of fertility, I considered hCG as an ideal target, for intervention.

Rendering hCG immunogenic

HCG is a “self” molecule. The foetus is literally bathing in high levels of hCG during embryonic development. The immune system of any woman would not react to hCG to evoke an immunological response to hCG. It had to be rendered “foreign”, while still preserving the native conformation of the molecule. We thought of linking it to another protein, a carrier to which the immune system of the woman should react readily. Why not link hCG or still better its Beta subunit (being given that alpha subunit of hCG is common to FSH, LH & TSH, three other pituitary hormones) to Tetanus Toxoid (TT)? TT is available in unlimited amounts and at cheap rates. Furthermore, even if the carrier strategy fails to work for hCG, immunization against tetanus will be beneficial to the woman. In those years a large number of women delivering a child in aseptic conditions in the field or home used to die of ante-natal tetanus.

HCG-β-TT was indeed immunogenic

The conjugate of hCGβ-TT had to be tested in women for its ability to induce the formation of anti-hCG antibodies. Four women, who had voluntary tubectomy after having given birth to several children agreed to vaccination. They were given 4 injections of hCG β-TT at fortnightly intervals. To our delight, all of them formed antibodies against both hCG and tetanus [3,4]. These were independent set of antibodies. Administration of a load dose of hCG brought down temporarily the anti-hCG titres without any effect on anti-tetanus titres (Figure 1) is a recapitulation of these observations in one of these women.