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Plasmodium falciparum is an intracellular protozoan parasite that infects erythrocytes and hepatocytes. The blood stage of its life cycle causes substantial morbidity and mortality associated with millions of infections each year, motivating an intensive search for potential components of a multi-subunit vaccine. In this study, we present data showing that antibodies from natural infections can recognize a recombinant form of the relatively conserved merozoite surface antigen, PfRH5. Furthermore, we performed invasion inhibition assays on clinical isolates and laboratory strains of P. falciparum in the presence of affinity purified antibodies to RH5 and show that these antibodies can inhibit invasion in vitro. [ABSTRACT FROM AUTHOR]

Background. Schistosome infections are often clinically silent, but some individuals develop severe pathological reactions. In several disease processes, T-helper 17 (Th17) cells have been linked to tissue injuries, while regulatory T cells (Tregs) are thought to downmodulate inflammatory reactions. We assessed whether bladder pathology in human Schistosoma haematobium infection is related to the balance of Th17 cells and Tregs. We used a murine model of Schistosoma mansoni infection to further investigate whether the peripheral profiles reflected ongoing events in tissues.Methods. We characterized T-helper cell subsets in the peripheral blood of children residing in a S. haematobium–endemic area and in the peripheral blood, spleen, and hepatic granulomas of S. mansoni–infected high-pathology CBA mice and low-pathology C57BL/6 mice.Results. S. haematobium–infected children with bladder pathology had a significantly higher percentage of Th17 cells than those without pathology. Moreover, the Th17/Treg ratios were significantly higher in infected children with pathology, compared with infected children without pathology. Percentages of interleukin 17–producing cells were significantly higher in spleen and granulomas of CBA mice, compared with C57BL/6 mice. This difference was also reflected in the peripheral blood.Conclusions. This is the first study to indicate that Th17 cells may be involved in the pathogenesis of human schistosomiasis. [ABSTRACT FROM AUTHOR]

Background: The 2014 West African outbreak of Ebola virus disease highlighted the urgent need to develop an effective Ebola vaccine., Methods: We undertook 2 phase 1 studies assessing safety and immunogenicity of the viral vector modified vaccinia Ankara virus vectored Ebola Zaire vaccine (MVA-EBO-Z), manufactured rapidly on a new duck cell line either alone or in a heterologous prime-boost regimen with recombinant chimpanzee adenovirus type 3 vectored Ebola Zaire vaccine (ChAd3-EBO-Z) followed by MVA-EBO-Z. Adult volunteers in the United Kingdom (n = 38) and Senegal (n = 40) were vaccinated and an accelerated 1-week prime-boost regimen was assessed in Senegal. Safety was assessed by active and passive collection of local and systemic adverse events., Results: The standard and accelerated heterologous prime-boost regimens were well-tolerated and elicited potent cellular and humoral immunogenicity in the United Kingdom and Senegal, but vaccine-induced antibody responses were significantly lower in Senegal. Cellular immune responses measured by flow cytometry were significantly greater in African vaccinees receiving ChAd3 and MVA vaccines in the same rather than the contralateral limb., Conclusions: MVA biomanufactured on an immortalized duck cell line shows potential for very large-scale manufacturing with lower cost of goods. This first trial of MVA-EBO-Z in humans encourages further testing in phase 2 studies, with the 1-week prime-boost interval regimen appearing to be particularly suitable for outbreak control., Clinical Trials Registration: NCT02451891; NCT02485912., (© The Author(s) 2018. Published by Oxford University Press for the Infectious Diseases Society of America.)