Consistent Safety and Infectivity in Sporozoite Challenge Model of Plasmodium vivax in Malaria-Naive Human Volunteers

• Autor(a) principal: Herrera, Socrates
• Data de Publicação: 2011
• Outros Autores: Solarte, Yezid, Jordan-Villegas, Alejandro, Echavarria, Juan Fernando, Rocha, Leonardo, Palacios, Ricardo [UNIFESP], Ramirez, Oscar, Velez, Juan Diego, Epstein, Judith E., Richie, Thomas L., Arevalo-Herrera, Myriam
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://dx.doi.org/10.4269/ajtmh.2011.09-0498; http://repositorio.unifesp.br/handle/11600/33398

A safe and reproducible Plasmodium vivax infectious challenge method is required to evaluate the efficacy of malaria vaccine candidates. Seventeen healthy Duffy (+) and five Duffy (-) subjects were randomly allocated into three (A-C) groups and were exposed to the bites of 2-4 Anopheles albimanus mosquitoes infected with Plasmodium vivax derived from three donors. Duffy (-) subjects were included as controls for each group. Clinical manifestations of malaria and parasitemia were monitored beginning 7 days post-challenge. All Duffy (+) volunteers developed patent malaria infection within 16 days after challenge. Prepatent period determined by thick smear, was longer for Group A (median 14.5 d) than for Groups B and C (median 10 d/each). Infected volunteers recovered rapidly after treatment with no serious adverse events. the bite of as low as two P vivax-infected mosquitoes provides safe and reliable infections in malaria-naive volunteers, suitable for assessing antimalarial and vaccine efficacy trials.