Abstract

PIP: The National Institute of Immunology in New Delhi, India, is conducting clinical trials of a prototype birth control vaccine. 88 20-36 year old women receive a series of 3 injections of 300 mcg human chorionic gonadotropin (hCG) vaccine to theoretically protect them from pregnancy for 1 year. After 1 year, they receive a booster shot to protect them for another year or not receive the booster, thereby resulting in a return to fertility. So far, only 1 pregnancy in 821 menstrual cycles has occurred. In women who do not use contraception, 821 cycles would normally result in 250-300 pregnancies. The developer of the vaccine thinks that these results confirm its effectiveness. The vaccine stimulates antibodies against hCG, thus keeping hCG from preparing the uterus for implantation. Some advantages include the following: it is reversible and effective for 1 year, does not alter women's physiology, and is less intrusive than other contraceptives. The International Development Research Centre of the Government of Canada has supported this vaccine's research since 1974. The Institute is now conducting research on a new contraceptive method using the purified extract of the neem tree called praneem. Researchers have injected it into the uterus of rats and monkeys. They hope it can be a safe and effective method for women to use during the 3 months when they receive their vaccine shots. The Institute is also working on perfecting the delivery system of the vaccine, e.g., a biodegradable implant releasing the required dosage over 1 year. It is also developing a finger-prick test to determine whether women who have accepted the vaccine are producing enough antibodies. Despite the progress, more research is needed.