Accuracy and efficacy of pre-dengue vaccination screening for previous dengue infection with a new dengue rapid diagnostic test: a retrospective analysis of phase 3 efficacy trials.

Background: A dengue pre-vaccination test that is convenient, highly specific, and highly sensitive is still needed. The OnSite Dengue IgG rapid diagnostic test (RDT) is a new rapid diagnostic test specifically designed for pre-vaccination screening. We aimed to retrospectively assess the efficacy of a tetravalent dengue vaccine (CYD-TDV) in participants determined to be dengue seropositive by the OnSite IgG RDT and to evaluate assay performances.

Performance Evaluation of a Dengue IgG Rapid Diagnostic Test Designed to Determine Dengue Serostatus as Part of Prevaccination Screening.

The World Health Organization has recommended prevaccination screening for prior dengue infection as the preferred approach prior to vaccination with the dengue vaccine CYD-TDV. These screening tests need to be highly specific and sensitive, and deliverable at the point-of-care. We evaluate here the sensitivity and specificity of the newly developed Dengue IgG rapid diagnostic test (RDT).

Accuracy and efficacy of pre-dengue vaccination screening for previous dengue infection with five commercially available immunoassays: a retrospective analysis of phase 3 efficacy trials.

Background: The tetravalent dengue vaccine (CYD-TDV) has been shown to provide protection against dengue disease over 5-year follow-up in participants with previous dengue infection, but increased the risk of dengue hospitalisation and severe dengue during long-term follow-up in those without previous dengue infection. WHO recommended pre-vaccination screening to identify those with previous dengue infection (ie, dengue seropositive) who would benefit from vaccination. We re-evaluated CYD-TDV efficacy in those identified as dengue seropositive using five commercially available immunoassays, and assessed immunoassay performance.

Safety biomarkers for development of vaccines and biologics: Report from the safety biomarkers symposium held on November 28-29, 2017, Marcy l'Etoile, France.

Vaccines prevent infectious diseases, but vaccination is not without risk and adverse events are reported although they are more commonly reported for biologicals than for vaccines. Vaccines and biologicals must undergo vigorous assessment before and after licensure to minimise safety concerns. Potential safety concerns should be identified as early as possible during the development for vaccines and biologicals to minimize investment risk.

Evaluation of dengue serological tests available in Puerto Rico for identification of prior dengue infection for prevaccination screening.

We assessed a dengue IgG rapid diagnostic test (RDT) and IgG enzyme-linked immunosorbent assay (ELISA) to determine their suitability for dengue prevaccination screening. Each exhibited ≥99% specificity. The RDT demonstrated no Zika cross-reactivity, while the ELISA displayed greater sensitivity.

Evaluation of rapid diagnostic tests and conventional enzyme-linked immunosorbent assays to determine prior dengue infection.

Background: In September 2018, the World Health Organization recommended that prevaccination screening be used with the tetravalent dengue vaccine (CYD-TDV), to ensure that only individuals with evidence of prior dengue infection (PDI) are vaccinated. Dengue rapid diagnostic tests (RDTs) would offer a potential solution for prevaccination screening at the point-of-care, but data on performance of available RDTs for identifying PDI are limited. We determined the suitability of four dengue RDTs and two conventional enzyme-linked immunosorbent assays (ELISAs) to identify PDI and evaluated cross-reactivity with co-circulating flaviviruses.

Prostate cancer biomarker annexin A3 detected in urines obtained following digital rectal examination presents antigenic variability.

Objectives: Annexin A3 (ANXA3) is a potential marker for prostate cancer (PCa). We aimed to develop robust immunoassays suitable for quantifying ANXA3 in urine samples obtained following digital rectal examination (DRE) in order to facilitate the diagnostic performance evaluation of this marker.

Design And Methods: Anti-ANXA3 monoclonal antibodies were generated and their epitopes mapped.

Characterization of three amino-functionalized surfaces and evaluation of antibody immobilization for the multiplex detection of tumor markers involved in colorectal cancer.

Antibody microarrays are powerful and high-throughput tools for screening and identifying tumor markers from small sample volumes of only a few microliters. Optimization of surface chemistry and spotting conditions are crucial parameters to enhance antibodies' immobilization efficiency and to maintain their biological activity. Here, we report the implementation of an antibody microarray for the detection of tumor markers involved in colorectal cancer.

Identification and verification of heat shock protein 60 as a potential serum marker for colorectal cancer.

Colorectal cancer (CRC) is a major public health issue worldwide, and novel tumor markers may contribute to its efficient management by helping in early detection, prognosis or surveillance of disease. The aim of our study was to identify new serum biomarkers for CRC, and we followed a phased biomarker discovery and validation process to obtain an accurate preliminary assessment of potential clinical utility. We compared colonic tumors and matched normal tissue from 15 CRC patients, using two-dimensional difference gel electrophoresis (2D-DIGE), and identified 17 proteins that had significant differential expression.

Analysis of high molecular mass proteins larger than 150 kDa using cyanogen bromide cleavage and conventional 2-DE.

Proteomic approaches including high-resolution 2-DE are providing the tools needed to discover disease-associated biomarkers in complex biological samples. Although 2-DE is an extremely powerful approach to analyze the proteome, the separation of proteins with extreme molecular masses still remains an issue requiring improvement. Because high molecular mass (HMM) proteins larger than 150 kDa have already been observed to be differentially expressed in several pathologies such as cancer, we developed an original strategy to analyze this part of the proteome that is not easily separated by 2-DE in polyacrylamide gels.

Coadsorption of HIV-1 p24 and gp120 proteins to surfactant-free anionic PLA nanoparticles preserves antigenicity and immunogenicity.

Biodegradable micro- or nanoparticles with surface adsorbed antigens represent a promising method for in vivo delivery of vaccines. Most vaccines, licensed or under development, are based on combined delivery of multiple antigens. Thus, we investigated the feasibility of combining two vaccine antigens, HIV-1 p24 and gp120 proteins, on the surface of surfactant-free anionic PLA nanoparticles obtained by an improved solvent diffusion method.

Surfactant-free anionic PLA nanoparticles coated with HIV-1 p24 protein induced enhanced cellular and humoral immune responses in various animal models.

Microparticles and nanoparticles prepared with poly(D,L-lactide-co-glycolide) (PLGA) or poly(D,L-lactide) (PLA) polymers represent a promising method for in vivo delivery of encapsulated peptide, protein or DNA antigens. However, one major issue that limits the potential of these delivery systems is the instability or the degradation of the entrapped antigen. Charged microparticles carrying surface adsorbed antigen were developed to resolve this problem and appear more suitable for vaccine applications.

Cationic PLA nanoparticles for DNA delivery: comparison of three surface polycations for DNA binding, protection and transfection properties.

Biodegradable cationic nanoparticles (cNP) made of poly(lactide) (PLA) have been shown to be promising carrier systems for in vivo DNA delivery and immunization. In previous work, we have described a versatile approach for the elaboration of cationic PLA cNP based on the use of pre-formed particles and subsequent adsorption of a model polycation, the poly(ethylenimine) (PEI). Here, we evaluated two more polycations, chitosan and poly(2-dimethyl-amino)ethyl methacrylate (pDMAEMA)) to determine the most suitable one for the development of PLA cNP as DNA carriers.

Evolutionary dynamics of the glycan shield of the human immunodeficiency virus envelope during natural infection and implications for exposure of the 2G12 epitope.

Elucidation of the kinetics of exposure of neutralizing epitopes on the envelope of human immunodeficiency virus type 1 (HIV-1) during the course of infection may provide key information about how HIV escapes the immune system or why its envelope is such a poor immunogen to induce broadly efficient neutralizing antibodies. We analyzed the kinetics of exposure of the epitopes corresponding to the broadly neutralizing human monoclonal antibodies immunoglobulin G1b12 (IgG1b12), 2G12, and 2F5 at the quasispecies level during infection. We studied the antigenicity and sequences of 94 full-length envelope clones present during primary infection and at least 4 years later in four HIV-1 clade B-infected patients.

Short communication: retrospective study to time the introduction of HIV type 1 non-B subtypes in Lyon, France, using env genes obtained from primary infection samples.

Using blood samples from primary HIV-1 infection (PHI) patients obtained in Lyon, France, we characterized the newly transmitted HIV-1 variants in this area during the 1992-1996 period. As PHI samples allowed the precise timing of the transmission event, we were able to date the introduction of non-B subtypes or recombinant forms of the virus in Lyon. Genomic DNA from 18 HIV-1-positive patients at primary infection was used to amplify the full-length env gene by nested PCR; after cloning, the gene was sequenced for subsequent phylogenetic analysis.

Evaluation in rhesus macaques of Tat and rev-targeted immunization as a preventive vaccine against mucosal challenge with SHIV-BX08.

Recent evidence suggests that a CD8-mediated cytotoxic T-cell response against the regulatory proteins of human immunodeficiency virus (HIV) or simian immunodeficiency virus (SIV) may control infection after pathogenic virus challenge. Here, we evaluated whether vaccination with Tat or Tat and Rev could significantly reduce viral load in nonhuman primates. Rhesus macaques were primed with Semliki forest Virus (SFV) expressing HIV-1 tat (SFV-tat) and HIV-1 rev (SFV-rev) and boosted with modified vaccinia virus Ankara (MVA) expressing tat and rev.