[Immunoprophylaxis and pathology of parasitic infection]

In the present paper, a brief introductory part concerned with a number of general concepts of the host-parasite relationship is followed by a discussion of the current situation regarding immunoprophylaxis of infestation by protozoa and helminths. Subsequent speculations on the possibilities of immunological interference in the host-parasite relationship in view of recent developments in the manufacture of vaccines are engaged in. The complicated character of interactions of host and parasite is illustrated in a number of instances of mechanisms utilized by parasites to avoid resistance by the host.