Phase I Safety and Immunogenicity Trial of Plasmodium vivax CS Derived Long Synthetic Peptides Adjuvanted with Montanide ISA 720 or Montanide ISA 51

We assessed the safety, tolerability, and immunogenicity of a mixture of three synthetic peptides derived from the Plasmodium vivax circumsporozoite protein formulated in Montanide ISA 720 or Montanide ISA 51. Forty healthy malaria-naive volunteers were allocated to five experimental groups (A-E): four groups (A-D) were immunized intramuscularly with 50 and 100 mu g/dose injections of a mixture of N, R, and C peptides formulated in the two different adjuvants at 0, 2, and 4 months and one group was administered placebo. Vaccines were immunogenic, safe, well tolerated, and no serious adverse events related to the vaccine occurred. Seroconversion occurred in >90% of the vaccines and antibodies recognized the sporozoite protein on immunofluorescent antibody test. Vaccines in Montanide ISA 51 showed a higher sporozoite protein recognition and interferon production. Results encourage further testing of the vaccine protective efficacy.World Health Organization Initiative for Vaccine ResearchNational Institute of Allergy and Infectious Diseases (NIAID)Colombian National Research Council, COLCIENCIASColombian Ministry for Social ProtectionMalaria Vaccine and Drug Development Center FoundationConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)National Institutes of Health (NIH)Malaria Vaccine & Drug Dev Ctr, Cali, ColombiaUniv Valle, Fac Salud, Inst Inmunol, Cali, ColombiaCtr Med Imbanaco, Unidad Med Interna & Epidemiol Clin, Cali, ColombiaFdn Clin Valle del Lili, Cali, ColombiaUniversidade Federal de São Paulo, Div Infect Dis, Disciplina Infectol, São Paulo, BrazilFamily Hlth Int, Durham, NC USAUniv Lausanne, Inst Biochem, Lausanne, SwitzerlandUniversidade Federal de São Paulo, Div Infect Dis, Disciplina Infectol, São Paulo, BrazilWorld Health Organization Initiative for Vaccine Research: LA35735GNational Institute of Allergy and Infectious Diseases (NIAID): 49486/TMRCColombian National Research Council, COLCIENCIAS: 487-2003Colombian Ministry for Social Protection: conv. 255-2004National Institutes of Health (NIH): NIH/NO1-AI-05403Web of Scienc