The predictor of mortality outcome in adult patients with Ebola virus disease during the 2014-2015 outbreak in Guinea.

The purpose of this study was to examine the association of any demographic and clinical factors with mortality outcome among adult patients with Ebola virus disease (EVD) in Guinea. This retrospective observational study analyzed medical records of laboratory confirmed EVD adult patients during the 2014-2015 EVD outbreak in Guinea. The associations between any demographic or clinical variables and mortality outcome of EVD were assessed using univariate and multivariate logistic regression analyses. Of 2,310 EVD adult patients included for analysis, the overall case fatality rate was 68.1%. Univariate analyses identified factors possibly associated with mortality outcome, including patient age (p < 0.001), history of visiting or close contact with a suspected or confirmed EVD patient (p = 0.035), and seven clinical symptoms on admission, i.e., fever (p = 0.003), hiccups (p < 0.001), vomiting (p = 0.003), diarrhea (p < 0.001), cough (p = 0.001), sore throat (p = 0.016), and unexplained bleeding (p = 0.021). The multivariate analysis showed that patient age was independently associated with mortality outcome of EVD (OR = 1.06; 95%CI = 1.03-1.09; p < 0.001), while none the of clinical symptoms on admission were significantly associated with the mortality outcome. Our analysis indicates that older age was the only independent factor associated with death among EVD adult patients in Guinea. This suggests that older EVD patients should receive intensive medical care and be carefully monitored.

Effect of nanoparticle coating on the immunogenicity of plasmid DNA vaccine encoding P. yoelii MSP-1 C-terminal.

In order to assess a new strategy for DNA vaccine formulation and delivery, plasmid encoding Plasmodium yoelii MSP-1 C-terminal was formulated with newly designed nanoparticle-an anionic ternary complex of polyethylenimine and γ-polyglutamic acid (pVAX-MSP-1/PEI/γ-PGA), and intravenously administered to C57BL/6 mice in four different doses, three times at 3-week interval. Antibody response as determined by ELISA, IFA and Western blot, was dose-dependent and subsequent challenge with 10(5)P. yoelii-infected red blood cells revealed 33-60% survival in repeated experiments at a dose of 80 µg pDNA/mouse. IgG subtypes and cytokine levels in the serum and culture supernatants of stimulated spleen cells were also measured. Antigen-specific IgG response provoked by the DNA vaccination was dominated by IgG1 and IgG2b. Although the elevation of IL-12p40 and IFN-γ was marginal (P≥0.354) in the coated group, interleukin-4 levels were significantly higher (P≥0.013) in the coated group than in the naked or control group, suggesting a predominant Th2-type CD4(+) T cell response. These results therefore, overall indicate the possibility of selection and optimization of DNA vaccine formulation for intravenous delivery and may be useful in designing a nanoparticle-coated DNA vaccine that could optimally elicit a desired antibody response for various disease conditions.

Selection and identification of malaria vaccine target molecule using bioinformatics and DNA vaccination.

Following a genome-wide search for a blood stage malaria DNA-based vaccine using web-based bioinformatic tools, 29 genes from the annotated Plasmodium yoelii genome sequence (www.PlasmoDB.org and www.tigr.org) were identified as encoding GPI-anchored proteins. Target genes were those with orthologues in P. falciparum, containing an N-terminal signal sequence containing hydrophobic amino acid stretch and signal P criteria, a transmembrane-like domain and GPI anchor motif. Focusing on the blood stage, we extracted mRNA from pRBCs, PCR-amplified 22 out of the 29 selected genes, and eventually cloned nine of these into a DNA vaccine plasmid, pVAX 200-DEST. Biojector-mediated delivery of the nine DNA vaccines was conducted using ShimaJET to C57BL/6 mice at a dose of 4 µg/mouse three times at an interval of 3 weeks. Two weeks after the second booster, immunized mice were challenged with P. y. yoelii 17XL-parasitized RBCs and the level of parasitaemia, protection and survival was assessed. Immunization with one gene (PY03470) resulted in 2-4 days of delayed onset and level of parasitaemia and was associated with increased survival compared to non-immunized mice. Antibody production was, however, low following DNA vaccination, as determined by immunofluorescence assay. Recombinant protein from this gene, GPI8p transamidase-related protein (rPyTAM) in PBS or emulsified with GERBU adjuvant was also used to immunize another set of C57BL/6 mice with 10-20 µg/mouse three times at 3-week interval. Higher antibody response was obtained as determined by ELISA with similar protective effects as observed after DNA vaccination.