Little is known regarding the likelihood of recombination between any given pair of nonidentical HIV-1 viruses in vivo. The present study analyzes the HIV-1 quasispecies in the C1C2 region of env, the vif-vpr-vpu accessory gene region, and the reverse transcriptase region of pol. These sequences were amplified from samples obtained sequentially over a 12-to 33-month period from five dually HIV-1-infected subjects. Analysis of an average of 248 clones amplified from each subject revealed no recombinants within the three loci studied of the subtypediscordant infecting strains, whose genetic diversity was >11% in env. In contrast, two subjects who were initially coinfected by two subtype-concordant variants with genetic diversity of 7.4% in env were found to harbor 10 unique recombinants of these strains, as exhibited by analysis of the env gene. The frequent recombination observed among the subtype-concordant strains studied herein correlates with prior sequence analyses that have commonly found higher rates of recombination at loci bearing the most conserved sequences, demonstrating an important role for sequence identity in HIV-1 recombination. Viral load analysis revealed that the samples studied contained an average of 8125 virus copies=ml (range, 882-31,626 copies=ml), signifying that the amount of viral RNA in the samples was not limiting for studying virus diversity. These data reveal that recombination between genetically distant strains may not be an immediate or common outcome to dual infection in vivo and suggest critical roles for viral and host factors such as viral fitness, virus diversity, and host immune responses that may contribute to limiting the frequency of intersubtype recombination during in vivo dual infection.

Development of effective vaccines against emerging infectious diseases (EID) can take as much or more than a decade to progress from pathogen isolation/identification to clinical approval. As a result, conventional approaches fail to produce field-ready vaccines before the EID has spread extensively. Lassa is a prototypical emerging infectious disease endemic to West Africa for which no successful vaccine is available. We established the VaxCelerate Consortium to address the need for more rapid vaccine development by creating a platform capable of generating and pre-clinically testing a new vaccine against specific pathogen targets in less than 120 d. A self-assembling vaccine is at the core of the approach. It consists of a fusion protein composed of the immunostimulatory Mycobacterium tuberculosis heat shock protein 70 (MtbHSP70) and the biotin binding protein, avidin. Mixing the resulting protein (MAV) with biotinylated pathogen-specific immunogenic peptides yields a self-assembled vaccine (SAV). To meet the time constraint imposed on this project, we used a distributed R&D model involving experts in the fields of protein engineering and production, bioinformatics, peptide synthesis/design and GMP/GLP manufacturing and testing standards. SAV immunogenicity was first tested using H1N1 influenza specific peptides and the entire VaxCelerate process was then tested in a mock live-fire exercise targeting Lassa fever virus. We demonstrated that the Lassa fever vaccine induced significantly increased class II peptide specific interferon-g CD4C T cell responses in HLA-DR3 transgenic mice compared to peptide or MAV alone controls. We thereby demonstrated that our SAV in combination with a distributed development model may facilitate accelerated regulatory review by using an identical design for each vaccine and by applying safety and efficacy assessment tools that are more relevant to human vaccine responses than current animal models.

suggests that phylotypes differ phenotypically. An accurate survey of genetic diversity and population structure will facilitate responsible selection of drug and/or vaccine targets for future treatments, and will enable better understanding of virulence factors contributing to the wide range of severity of symptoms associated with trichomoniasis. Objectives To develop a novel diagnostic protein in order to enhance early detection of syphilis infections and improve overall syphilis diagnosis. Methods Using pooled serum samples from patients infected with syphilis, immunoreactive regions of two previously identified diagnostic protein candidates, Tp0326 and Tp0453, were elucidated. Focusing on these regions, a chimeric protein construct was created for expression in Escherichia coli and expression conditions were optimised to produce soluble protein expression. This Tp0326/Tp0453 chimeric construct was screened against serum samples from; patients with primary, secondary, latent, and neurosyphilis and uninfected individuals. These results were directly compared to the rapid plasma regain (RPR) test, and the microhemagglutination assay for T pallidum (MHA-TP). P4-S3.08Results Screening results show high degrees of sensitivity and specificity for the Tp0326/Tp0453 chimeric construct, identifying all stages of syphilis infection from early primary to late latent. Conclusion The Tp0326/Tp0453 chimera shows promise as a new diagnostic antigen for detecting all stages of syphilis infection and for development into point-of-care diagnostic test formats. Objective Trichomonas vaginalis, a highly prevalent non-viral sexually transmitted infection, has been shown to be infected by a doublestranded RNA virus known as T vaginalis virus (TVV). The presence of this virus has been associated with increased trafficking of the immunogenic P270 to the surface of the parasite, and has therefore been hypothesised to be an important virulence factor in trichomoniasis. In the present study, we investigate the prevalence of TVV in globally distributed T vaginalis isolates and find an association between TVV infection and genetically distinct T vaginalis populations. Methods 150 T vaginalis isolates from the USA, Mexico, Italy, Southern Africa, Papua New Guinea and Australia were screened for TVV infection by running total RNA extract on 1% agarose gels to detect the presence or absence of the diagnostic 4.5 kb dsRNA genome of the virus. The prevalence of TVV in genetically distinct T vaginalis phylotypes was compared using c 2 tests. Results TVV was found to be present in 37% of T vaginalis isolates. We find a difference in the prevalence of TVV infection between genetically distinct populations of parasites, with 3% of phylotype 1 isolates containing the virus vs 73% of phylotype 2 parasites (<0.001). P4-S3.09 THE PREVALENCE OF TRICHOMONAS VAGINALISConclusions TVV prevalence varies between T vaginalis phylotypes 1 and 2. This finding has implications suggesting that TVV is transmitted vertically among parasites, as more closely relate...