Immunization against Malaria. Increased Protection by Vaccination of Ducklings with Saline-Insoluble Residues of Plasmodium lophurae mixed with a Bacterial Toxin.

Summary There is an intriguing parallelism between the known absence of the Forssman hapten in man and certain animals and the known susceptibility of man and these animals to plasmodial infections. Experiments outlined in this paper designed to increase the resistance of ducklings to infections of P. lophurae by preliminary treatment with materials containing this hapten have yielded largely negative results.