On-line version ISSN 1657-9534
HERRERA, Sócrates et al. The process for the development of a vaccine against the hepatic phase of Plasmodium vivax. Colomb Med [online]. 2005, vol.36, n.1, pp. 5-15. ISSN 1657-9534.
INTRODUCTION: Plasmodium vivax causes approximately 80-100 million clinical cases every year. It is the most prevalent human malaria parasite in the American continent and its prevalence is second only to P. falciparum worldwide. Due to the emergence of medication-resistant parasites and an increase in insecticide-resistant mosquitoes, research to find a vaccine that could prevent or limit the clinical manifestations of the disease has increased greatly. During the last two decades, significant progress has been achieved in this attempt; however, the development of a P. vivax vaccine has been hampered due to the lack of sustainable in vitro parasite cultures. OBJECTIVES: We describe the development and testing of a vaccine to P. vivax pre-erythrocytic stages. We selected the circumsporozoite (CS) protein, an antigen abundantly expressed on the parasite surface. METHODOLOGY: After extensive immunological characterization in vitro, three long peptides (N, R and C) were synthesized, and the toxicity and immunogenicity of these peptides were thoroughly assessed in animals. To determine the safety and immunogenicity in humans, a randomized, double blind clinical trial was conducted. The trial included 23 healthy volunteers who received 100 µg of N, R and C of each peptide formulated in Montanide ISA-720 adjuvant. CONCLUSIONS: The vaccination was well tolerated and proven to be safe in both animals and volunteers; thus, additional clinical trials utilizing this vaccine candidate are indicated.
Keywords : P. vivax; Malaria; Vaccine; Pre-erythrocytic stages; Clinical trials.