View Point- How reliable are models for malaria vaccine development? Lessons from irradiated sporozoite immunizations

Models occupy a key position in the development of anti-parasitic vaccines, yet thier relevance has been seldom addressed. It is customary to admit that malaria vaccine development requires easy-to-handle, laboratory models. Animal models involving predominantly inbred rodents and primates as parasite hosts are currently the basic tools for the study of host-parasite interactions. Literature however indicated that the induction of host protection is more difficult in natural host-parasite pairs than in experimental models of parasite infection. Moreover different models delineate a wide range of host-pathogen relationship profiles providing a mosaic of contradictory informations, yet there is little incentive to delineate thier relevance or to exploit recent advances to develop inmproved model systems. In this context the analysis of natural host-parasite interactions between Plasmodium berghei and its mammalian host and reservoir, the tree rat Grammomys surdaster could be of relevance in the study of host-parasite interactions

Fortified Snack Reduced Anemia in Rural School-Aged Children of Haiti: A Cluster-Randomized, Controlled Trial

BackgroundNutrition in the school-aged child matters for brain development and public policy investments globally. Our group previously conducted a trial in urban schools of Haiti to examine the effects of a fortified peanut butter snack, Vita Mamba, with limited findings for anemia.ObjectiveWe aimed to test the hypothesis that Vita Mamba, with systematic deworming in both study arms, would significantly reduce anemia among rural, school-aged children.MethodsA cluster, randomized longitudinal study was conducted in two rural communities of the North-East Department of Haiti, 2014–2015. Healthy children ages 3–16 years were enrolled (n = 321) and assigned by school to intervention (Vita Mamba and deworming) and control (deworming). Vita Mamba contains 260 kcal and meets >75% of the Recommended Dietary Allowance for critical micronutrients. Multivariate regression analyses including propensity score matching techniques to correct for potential group imbalance (Kernel-based Matching and Propensity Score Weighting) were applied to examine difference-in-difference intervention effects.ResultsAt baseline, 51% of the children were anemic with no significant differences between study groups. Vita Mamba supplementation showed a consistent, positive effect across regression models on increasing Hb concentration and reducing the odds of anemia compared to the control group after adjusting for child age, vitamin A supplementation, milk consumption, and height-for-age z score. The average treatment effect for the treated in the Propensity Score Weighting models was 0.62±0.27 grams per 100 milliliters (g/dL) for Hb concentration (F = 4.64, P = 0.001), and the odds of anemia were reduced by 88% (Wald χ² = 9.77, P = 0.02). No differences in change in anthropometric markers were evident.ConclusionsSchool feeding programs that integrate fortified foods with deworming could reduce anemia burden with important implications for learning, health, and well-being. The rural-urban differences in anemia require further study.</div