[Immunological contraception--future possibilities in family planning]

In principle, immunological contraception is primarily a question of producing antibodies to block or inactivate a vital functional process. The antibodies can be used to elicit the corresponding antigen which, more or less modified, may then be used as a vaccination immunogen. The antibodies may also serve as the starting point in the production of new (antiidiotypic) antibodies, which have a certain potential function as a vaccine, owing to their antigenic capacity to stimulate the formation of functionally active antibodies. In addition to their use in developing a method of contraceptive vaccination (active immunisation), functional antibodies can also be used in passive immunisation. Such treatment during early gestation would result in abortion, and might be an alternative means of terminating pregnancy. In such cases, the antibodies might be combined with a toxin, yielding an immunotoxin exerting highly specific effects on the conceptus.