Analysis of multiple Plasmodium falciparum infections in Tanzanian children during the phase III trial of the malaria vaccine SPf66.
In the first phase III efficacy trial of the malaria vaccine SPf66 in Africa, MOIs in SPf66-and placebo-vaccinated children were analyzed by polymerase chain reaction-restriction fragment length polymorphism of the Plasmodium falciparum merozoite surface antigen 2 (MSA2).
MOIs were significantly reduced in asymptomatic vaccine recipients compared with those in asymptomatic placebo recipients ; however, no differences were observed among symptomatic children in the vaccine and control groups.
These results show that immunization with SPf66 modulates the course of naturally occurring infections, as reflected by reduced MOIs.
In placebo recipients, however, there was a significant negative correlation between numbers of infecting genotypes, as identified by MSA2, and morbidity.
Asymptomatic placebo recipients had an average of 5 concurrent infections, whereas children with clinical cases had an average of 3.4 infections.
These data provide further evidence that premunition from concurrent infections is important in immunity against clinical malaria.
No such effect of multiple infections was found in the vaccinated group.
Mots-clés Pascal : Paludisme, Protozoose, Parasitose, Infection, Plasmodium falciparum, Sporozoa, Protozoa, Variation antigénique, Typage, Génotype, Exploration microbiologique, Immunoprophylaxie, Enfant, Homme, Essai clinique phase III, Vaccination, Tanzanie, Afrique, Prévention
Mots-clés Pascal anglais : Malaria, Protozoal disease, Parasitosis, Infection, Plasmodium falciparum, Sporozoa, Protozoa, Antigenic variation, Typing, Genotype, Microbiological investigation, Immunoprophylaxis, Child, Human, Phase III trial, Vaccination, Tanzania, Africa, Prevention
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0256487
Code Inist : 002B05E02B4. Création : 11/06/1997.