* Division of Parasitic Diseases and Office of Scientific Services, Center for Infectious Diseases, Centers for Disease Control, U.S. Public Health Service, Department of Health and Human Services, Atlanta, Georgia 30333
| † The Walter and Eliza Hall Institute for Medical Research, Victoria 3050, Australia
| ‡ The New England Regional Primate Research Center, Harvard University, Cambridge, Massachusetts 02138
A protocol was developed for the testing of blood stage vaccines against Plasmodium falciparum using Peruvian Aotus vociferans and the Indochina I/CDC strain of the parasite. Three different fused polypeptide vaccines containing elements of the ring-infected erythrocyte surface antigen molecule combined with Freund's complete and Freund's incomplete adjuvants were tested to determine their ability to protect against overwhelming infection following challenge with this highly virulent strain of P. falciparum, and to invoke antibody responses as measured by a standard indirect immunofluorescence technique. Nine of 14 immunized animals exhibited some protection. Presented are the test procedures developed for the conduct of such trials with New World monkeys and the analysis of results that led to the identification of variables selected for study in future trials.