[AIDS: possibilities of active immunization].

The development of an AIDS vaccine represents a major challenge for medical research. Efforts are undertaken for the production of appropriate immunogens in sufficient quantity and purity, especially by the use of recombinant DNA technology. Unfortunately, all immunization experiments using chimpanzees were negative so far, since in no case infection could be prevented by vaccination. Nevertheless, immunization trials were started in humans, although it is unclear which type of immune response could mediate protection. It is at present not possible to predict at which time and if at all an AIDS vaccine will become available.