Rapid diagnostic test: a critical need for outbreak preparedness and response for high priority pathogens.

Rapid diagnostic tests (RDTs) are critical for preparedness and response against an outbreak or pandemic and have been highlighted in the 100 Days Mission, a global initiative that aims to prepare the world for the next epidemic/pandemic by driving the development of diagnostics, vaccines and therapeutics within 100 days of recognition of a novel Disease X threat.RDTs play a pivotal role in early case identification, surveillance and case management, and are critical for initiating deployment of vaccine and monoclonal antibodies. Currently available RDTs, however, have limited clinical sensitivity and specificity and inadequate validation. The development, validation and implementation of RDTs require adequate and sustained financing from both public and private sources. While the World Health Assembly recently passed a resolution on diagnostic capacity strengthening that urges individual Member States to commit resources towards this, the resolution is not binding and implementation will likely be impeded by limited financial resources and other competing priorities, particularly in low-income countries. Meanwhile, the diagnostic industry has not sufficiently invested in RDT development for high priority pathogens.Currently, vaccine development projects are getting the largest funding support among medical countermeasures. Yet vaccines are insufficient tools in isolation, and pandemic preparedness will be incomplete without parallel investment in diagnostics and therapeutics.The Pandemic Fund, a global financing mechanism recently established for strengthening pandemic prevention, preparedness and response, may be a future avenue for supporting diagnostic development.In this paper, we discuss why RDTs are critical for preparedness and response. We also discuss RDT investment challenges and reflect on the way forward.

Concentric and Eccentric Force Changes with Elastic Band and Isotonic Heavy Resistance Training: A Randomized Controlled Trial.

BACKGROUND: Inclusion of resistance training as part of a general fitness program to improve health, and lower risk of disease and injury is well established. Two common options to improve strength are elastic bands and weights. Comparison between elastic bands (as the sole resistance) to isotonic strengthening for concentric and eccentric strength outcomes following the use of low repetitions/heavy resistance has not been reported. HYPOTHESIS/PURPOSE: The purpose was to examine the effects of a four-week isotonic low repetitions/heavy resistance strengthening program compared to a low repetitions/heavy resistance elastic band strengthening program on shoulder external rotation, hip abduction, and elbow flexion concentric and eccentric isokinetic force production in college aged untrained females. STUDY DESIGN: Randomized Trial. METHODS: Twenty healthy females performed pre-and-post isokinetic (60 degrees/second) concentric/eccentric testing of the elbow flexors, shoulder external rotators, and hip abductors. Participants were randomly assigned to a four-week independent low repetitions/heavy resistance strengthening program performed with either elastic bands or isotonic exercises. RESULTS: A significant (p < 0.05) effect of time was found for eccentric elbow flexor and concentric and eccentric hip abduction force production in the elastic band group with post-test values greater than pre-test values. A significant (p < 0.05) effect of time was found for elbow flexor concentric and eccentric force production in the isotonic group with post-test values greater then pre-test values. No significant (p>0.05) effect of time was found for shoulder external rotator concentric and eccentric forces for both groups, the isotonic group's hip abduction concentric and eccentric force production and elastic band group's elbow flexion concentric force production. No significant effect of intervention (p >0.05) on concentric or eccentric elbow flexors, shoulder external rotators, or hip abductors force production was found, with pre-test and post-test values being similar between groups. CONCLUSION: Health care practitioners and coaches can consider the prescription of a heavy resistance training program with elastic bands or isotonic exercises for an independent exercise program and expect similar concentric and eccentric muscle force changes. LEVEL OF EVIDENCE: Level 2b.

Balanced Cellular and Humoral Immune Responses Targeting Multiple Antigens in Adults Receiving a Quadrivalent Inactivated Influenza Vaccine.

The role of T cell immunity has been acknowledged in recent vaccine development and evaluation. We tested the humoral and cellular immune responses to Flucelvax®, a quadrivalent inactivated seasonal influenza vaccine containing two influenza A (H1N1 Singapore/GP1908/2015 IVR-180 and H3N2 North Carolina/04/2016) and two influenza B (Iowa/06/2017 and Singapore/INFTT-16-0610/2016) virus strains, using peripheral blood mononuclear cells stimulated by pools of peptides overlapping all the individual influenza viral protein components. Baseline reactivity was detected against all four strains both at the level of CD4 and CD8 responses and targeting different proteins. CD4 T cell reactivity was mostly directed to HA/NA proteins in influenza B strains, and NP/M1/M2/NS1/NEP proteins in the case of the Influenza A strains. CD8 responses to both influenza A and B viruses preferentially targeted the more conserved core viral proteins. Following vaccination, both CD4 and CD8 responses against the various influenza antigens were increased in day 15 to day 91 post vaccination period, and maintained a Th1 polarized profile. Importantly, no vaccine interference was detected, with the increased responses balanced across all four included viral strains for both CD4 and CD8 T cells, and targeting HA and multiple additional viral antigens.

The Human Vaccines Project: Towards a comprehensive understanding of the human immune response to immunization.

Although the success of vaccination to date has been unprecedented, our inadequate understanding of the details of the human immune response to immunization has resulted in several recent vaccine failures and significant delays in the development of high-need vaccines for global infectious diseases and cancer. Because of the need to better understand the immense complexity of the human immune system, the Human Vaccines Project was launched in 2015 with the mission to decode the human immune response to accelerate development of vaccines and immunotherapies for major diseases. The Project currently has three programs: 1) The Human Immunome Program, with the goal of deciphering the complete repertoire of B and T cell receptors across the human population, termed the Human Immunome, 2) The Rules of Immunogenicity Program, with the goal of understanding the key principles of how a vaccine elicits a protective and durable response using a system immunology approach, and 3) The Universal Influenza Vaccine Initiative (UIVI), with the goal of conducting experimental clinical trials to understand the influence of influenza pre-exposures on subsequent influenza immunization and the mechanisms of protection. Given the dramatic advances in computational and systems biology, genomics, immune monitoring, bioinformatics and machine learning, there is now an unprecedented opportunity to unravel the intricacies of the human immune response to immunization, ushering in a new era in vaccine development.

An in-depth comparison of latent HIV-1 reactivation in multiple cell model systems and resting CD4+ T cells from aviremic patients.

The possibility of HIV-1 eradication has been limited by the existence of latently infected cellular reservoirs. Studies to examine control of HIV latency and potential reactivation have been hindered by the small numbers of latently infected cells found in vivo. Major conceptual leaps have been facilitated by the use of latently infected T cell lines and primary cells. However, notable differences exist among cell model systems. Furthermore, screening efforts in specific cell models have identified drug candidates for "anti-latency" therapy, which often fail to reactivate HIV uniformly across different models. Therefore, the activity of a given drug candidate, demonstrated in a particular cellular model, cannot reliably predict its activity in other cell model systems or in infected patient cells, tested ex vivo. This situation represents a critical knowledge gap that adversely affects our ability to identify promising treatment compounds and hinders the advancement of drug testing into relevant animal models and clinical trials. To begin to understand the biological characteristics that are inherent to each HIV-1 latency model, we compared the response properties of five primary T cell models, four J-Lat cell models and those obtained with a viral outgrowth assay using patient-derived infected cells. A panel of thirteen stimuli that are known to reactivate HIV by defined mechanisms of action was selected and tested in parallel in all models. Our results indicate that no single in vitro cell model alone is able to capture accurately the ex vivo response characteristics of latently infected T cells from patients. Most cell models demonstrated that sensitivity to HIV reactivation was skewed toward or against specific drug classes. Protein kinase C agonists and PHA reactivated latent HIV uniformly across models, although drugs in most other classes did not.

Safety and immunogenicity of CVD 1208S, a live, oral DeltaguaBA Deltasen Deltaset Shigella flexneri 2a vaccine grown on animal-free media.

A previous Phase 1 trial demonstrated that Shigella flexneri 2a deleted in guaBA, sen and set (strain CVD 1208) is well-tolerated and immunogenic after a single oral dose of 10(8) or 10(9) CFU. To facilitate further clinical development, the strain was reconstructed using animal-free media to conform to regulatory guidelines, and designated CVD1208S. Healthy inpatient volunteers were randomized (double-blind) to receive a single oral dose of either CVD 1208S (10(8) [n = 7] or 10(9) [n = 7] CFU) or placebo (n = 2). Both vaccine dosage levels were generally well-tolerated. Anti-lipopolysaccharide responses, measured as IgA antibody secreting cells, serum IgG, or fecal IgA levels, occurred in 7 (100%), three (43%) and two (29%) subjects following inoculation with 10(9) CFU, respectively. Interferon gamma production in response to Shigella antigens was observed in 1 of 4 (25%) and 4 of 7 (57%) subjects, following inoculation with 10(8) and 10(9) CFU. We conclude that CVD 1208S retains a favorable safety and immunogenicity profile after reconstruction on animal-free media, comparable to that seen with CVD 1208, which was constructed on media containing animal products, and shows promise as a live, oral Shigella vaccine.

Cutting edge: HLA-E binds a peptide derived from the ATP-binding cassette transporter multidrug resistance-associated protein 7 and inhibits NK cell-mediated lysis.

HLA-E is an MHC class Ib molecule that binds nonamer peptides derived from the leader sequence of MHC class 1a molecules and is the major ligand for CD94/NKG2 receptors found on NK and T cells. Using the MHC class Ia-null cell line 721.221, we find that surface HLA-E increases following heat shock at 42 degrees C and NK cell-mediated lysis is inhibited using heat-stressed 721.221 targets. We have used mass spectrometry to identify and sequence a novel peptide from HLA-E following heat shock, ALALVRMLI, derived from the transmembrane domain of the human ATP-binding cassette protein, multidrug resistance-associated protein, MRP7. Pulsing 721.221 targets with synthetic MRP7 peptide results in strong inhibition of NK cell-mediated lysis that is reversible using anti-CD94 and anti-class I mAbs. This report is the first to identify a non-MHC leader inhibitory peptide bound to HLA-E and provides insight into the immunoregulatory role of HLA-E during cell stress.