24 research outputs found
Computational and Systems Biology Advances to Enable Bioagent-Agnostic Signatures
Enumerated threat agent lists have long driven biodefense priorities. The
global SARS-CoV-2 pandemic demonstrated the limitations of searching for known
threat agents as compared to a more agnostic approach. Recent technological
advances are enabling agent-agnostic biodefense, especially through the
integration of multi-modal observations of host-pathogen interactions directed
by a human immunological model. Although well-developed technical assays exist
for many aspects of human-pathogen interaction, the analytic methods and
pipelines to combine and holistically interpret the results of such assays are
immature and require further investments to exploit new technologies. In this
manuscript, we discuss potential immunologically based bioagent-agnostic
approaches and the computational tool gaps the community should prioritize
filling
Establishment of an In Vitro Assay for Assessing the Effects of Drugs on the Liver Stages of Plasmodium vivax Malaria
Plasmodium vivax (Pv) is the second most important human malaria parasite. Recent data indicate that the impact of Pv malaria on the health and economies of the developing world has been dramatically underestimated. Pv has a unique feature in its life cycle. Uninucleate sporozoites (spz), after invasion of human hepatocytes, either proceed to develop into tens of thousands of merozoites within the infected hepatocytes or remain as dormant forms called hypnozoites, which cause relapses of malaria months to several years after the primary infection. Elimination of malaria caused by Pv will be facilitated by developing a safe, highly effective drug that eliminates Pv liver stages, including hypnozoites. Identification and development of such a drug would be facilitated by the development of a medium to high throughput assay for screening drugs against Pv liver stages. We undertook the present pilot study to (1) assess the feasibility of producing large quantities of purified, vialed, cryopreserved Pv sporozoites and (2) establish a system for culturing the liver stages of Pv in order to assess the effects of drugs on the liver stages of Pv. We used primaquine (PQ) to establish this assay model, because PQ is the only licensed drug known to clear all Pv hepatocyte stages, including hypnozoites, and the effect of PQ on Pv hepatocyte stage development in vitro has not previously been reported. We report that we have established the capacity to reproducibly infect hepatoma cells with purified, cyropreserved Pv spz from the same lot, quantitate the primary outcome variable of infected hepatoma cells and demonstrate the inhibitory activity of primaquine on the infected hepatoma cells. We have also identified small parasite forms that may be hypnozoites. These data provide the foundation for finalizing a medium throughput, high content assay to identify new drugs for the elimination of all Pv liver stages
Impact of meningococcal ACWY conjugate vaccines on pharyngeal carriage in adolescents: evidence for herd protection from the UK MenACWY programme
Objective: Serogroup W and Y invasive meningococcal disease increased globally from 2000 onwards. Responding to a rapid increase in serogroup W clonal complex 11 (W:cc11) invasive meningococcal disease, the UK replaced an adolescent booster dose of meningococcal C conjugate vaccine with quadrivalent MenACWY conjugate vaccine in 2015. By 2018, the vaccine coverage in the eligible school cohorts aged 14 to 19 years was 84%. We assessed the impact of the MenACWY vaccination programme on meningococcal carriage. Methods: An observational study of culture-defined oropharyngeal meningococcal carriage prevalence before and after the start of the MenACWY vaccination programme in UK school students, aged 15 to 19 years, using two cross-sectional studies: 2014 to 2015 “UKMenCar4” and 2018 “Be on the TEAM” (ISRCTN75858406). Results: A total of 10 625 participants preimplementation and 13 434 postimplementation were included. Carriage of genogroups C, W, and Y (combined) decreased from 2.03 to 0.71% (OR 0.34 [95% CI 0.27–0.44], p < 0.001). Carriage of genogroup B meningococci did not change (1.26% vs 1.23% [95% CI 0.77–1.22], p = 0.80) and genogroup C remained rare (n = 7/10 625 vs 17/13 488, p = 0.135). The proportion of serogroup positive isolates (i.e. those expressing capsule) decreased for genogroup W by 53.8% (95% CI –5.0 to 79.8, p = 0.016) and for genogroup Y by 30.1% (95% CI 8.9–46·3, p = 0.0025). Discussion: The UK MenACWY vaccination programme reduced carriage acquisition of genogroup and serogroup Y and W meningococci and sustained low levels of genogroup C carriage. These data support the use of quadrivalent MenACWY conjugate vaccine for indirect (herd) protection
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK.
BACKGROUND: A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials. METHODS: This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674. FINDINGS: Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0-75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4-97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8-80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3-4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation. INTERPRETATION: ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials. FUNDING: UK Research and Innovation, National Institutes for Health Research (NIHR), Coalition for Epidemic Preparedness Innovations, Bill & Melinda Gates Foundation, Lemann Foundation, Rede D'Or, Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca
Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK
Background
A safe and efficacious vaccine against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), if deployed with high coverage, could contribute to the control of the COVID-19 pandemic. We evaluated the safety and efficacy of the ChAdOx1 nCoV-19 vaccine in a pooled interim analysis of four trials.
Methods
This analysis includes data from four ongoing blinded, randomised, controlled trials done across the UK, Brazil, and South Africa. Participants aged 18 years and older were randomly assigned (1:1) to ChAdOx1 nCoV-19 vaccine or control (meningococcal group A, C, W, and Y conjugate vaccine or saline). Participants in the ChAdOx1 nCoV-19 group received two doses containing 5 × 1010 viral particles (standard dose; SD/SD cohort); a subset in the UK trial received a half dose as their first dose (low dose) and a standard dose as their second dose (LD/SD cohort). The primary efficacy analysis included symptomatic COVID-19 in seronegative participants with a nucleic acid amplification test-positive swab more than 14 days after a second dose of vaccine. Participants were analysed according to treatment received, with data cutoff on Nov 4, 2020. Vaccine efficacy was calculated as 1 - relative risk derived from a robust Poisson regression model adjusted for age. Studies are registered at ISRCTN89951424 and ClinicalTrials.gov, NCT04324606, NCT04400838, and NCT04444674.
Findings
Between April 23 and Nov 4, 2020, 23 848 participants were enrolled and 11 636 participants (7548 in the UK, 4088 in Brazil) were included in the interim primary efficacy analysis. In participants who received two standard doses, vaccine efficacy was 62·1% (95% CI 41·0–75·7; 27 [0·6%] of 4440 in the ChAdOx1 nCoV-19 group vs71 [1·6%] of 4455 in the control group) and in participants who received a low dose followed by a standard dose, efficacy was 90·0% (67·4–97·0; three [0·2%] of 1367 vs 30 [2·2%] of 1374; pinteraction=0·010). Overall vaccine efficacy across both groups was 70·4% (95·8% CI 54·8–80·6; 30 [0·5%] of 5807 vs 101 [1·7%] of 5829). From 21 days after the first dose, there were ten cases hospitalised for COVID-19, all in the control arm; two were classified as severe COVID-19, including one death. There were 74 341 person-months of safety follow-up (median 3·4 months, IQR 1·3–4·8): 175 severe adverse events occurred in 168 participants, 84 events in the ChAdOx1 nCoV-19 group and 91 in the control group. Three events were classified as possibly related to a vaccine: one in the ChAdOx1 nCoV-19 group, one in the control group, and one in a participant who remains masked to group allocation.
Interpretation
ChAdOx1 nCoV-19 has an acceptable safety profile and has been found to be efficacious against symptomatic COVID-19 in this interim analysis of ongoing clinical trials
Repeat region of plasmodium falciparum circumsporozoite protein does not recognize or bind to human hepatoma target cell
BUILDing SCHOLARS: enhancing diversity among U.S. biomedical researchers in the Southwest
Abstract Background and purpose With funding from the National Institutes of Health, BUILDing SCHOLARS was established at The University of Texas at El Paso with the goal of implementing, evaluating and sustaining a suite of institutional, faculty and student development interventions in order to train the next generation of biomedical researchers from the U.S. Southwest region, where the need is dire among underserved communities. The focus is on supporting the infrastructure necessary to train and mentor students so they persist on pathways across a range of biomedical research fields. The purpose of this article is to highlight the design and implementation of BUILDing SCHOLARS’ key interventions, which offer a systemic student training model for the U.S. Southwest. In-depth reporting of evaluation results is reserved for other technical publications. Program and key highlights BUILDing SCHOLARS uses a comprehensive regional approach to undergraduate training through a multi-institution consortium that includes 12 research partners and various pipeline partners across Texas, New Mexico, and Arizona. Through faculty collaborations and undergraduate research training, the program integrates social and behavioral sciences and biomedical engineering while emphasizing seven transdisciplinary nodes of biomedical research excellence that are common across partner institutions: addiction, cancer, degenerative and chronic diseases, environmental health, health disparities, infectious diseases, and translational biomedicine. Key interventions aim to: (1) improve institutional capacities by expanding undergraduate research training infrastructures; (2) develop an intra- and cross-institutional mentoring-driven “community of practice” to support undergraduate student researchers; (3) broaden the pool of student participants, improve retention, and increase matriculation into competitive graduate programs; and (4) support faculty and postdoctoral personnel by training them in research pedagogy and mentoring techniques and providing them with resources for increasing their research productivity. Student training activities focus on early interventions to maximize retention and on enabling students to overcome common barriers by addressing their educational endowments, science socialization, network development, family expectations, and material resources. Over the long term, BUILDing SCHOLARS will help increase the diversity of the biomedical research workforce in the U.S. by meeting the needs of students from the Southwest region and by serving as a model for other institutions
Chronic hepatitis C virus infection and subsequent HIV viral load among women with HIV initiating antiretroviral therapy
ObjectivesOne in four persons living with HIV is coinfected with hepatitis C virus (HCV). Biological and behavioral mechanisms may increase HIV viral load among coinfected persons. Therefore, we estimated the longitudinal effect of chronic HCV on HIV suppression after ART initiation among women with HIV (WWH).DesignHIV RNA was measured every 6 months among 441 WWH in the Women's Interagency HIV Study who initiated ART from 2000 to 2015.MethodsLog-binomial regression models were used to compare the proportion of study visits with detectable HIV RNA between women with and without chronic HCV. Robust sandwich variance estimators accounted for within-person correlation induced by repeated HIV RNA measurements during follow-up. We controlled for confounding and selection bias (because of loss to follow-up and death) using inverse probability-of-exposure-and-censoring weights.ResultsOne hundred and fourteen women (25%) had chronic HCV before ART initiation. Overall, the proportion of visits with detectable HIV RNA was similar among women with and without chronic HCV [relative risk (RR) 1.19 (95% CI 0.72, 1.95)]. Six months after ART initiation, the proportion of visits with detectable HIV RNA among women with chronic HCV was 1.88 (95% CI 1.41-2.51) times that among women without HCV, at 2 years, the ratio was 1.60 (95% CI 1.17-2.19), and by 6 years there was no difference (1.03; 95% CI 0.60-1.79).ConclusionChronic HCV may negatively impact early HIV viral response to ART. These findings reaffirm the need to test persons with HIV for HCV infection, and increase engagement in HIV care and access to HCV treatment among persons with HIV/HCV coinfection
Chronic hepatitis C virus infection and subsequent HIV viral load among women with HIV initiating antiretroviral therapy
One in four persons living with HIV is coinfected with hepatitis C virus (HCV). Biological and behavioral mechanisms may increase HIV viral load among coinfected persons. Therefore, we estimated the longitudinal effect of chronic HCV on HIV suppression after ART initiation among women with HIV (WWH).
HIV RNA was measured every 6 months among 441 WWH in the Women's Interagency HIV Study who initiated ART from 2000 to 2015.
Log-binomial regression models were used to compare the proportion of study visits with detectable HIV RNA between women with and without chronic HCV. Robust sandwich variance estimators accounted for within-person correlation induced by repeated HIV RNA measurements during follow-up. We controlled for confounding and selection bias (because of loss to follow-up and death) using inverse probability-of-exposure-and-censoring weights.
One hundred and fourteen women (25%) had chronic HCV before ART initiation. Overall, the proportion of visits with detectable HIV RNA was similar among women with and without chronic HCV [relative risk (RR) 1.19 (95% CI 0.72, 1.95)]. Six months after ART initiation, the proportion of visits with detectable HIV RNA among women with chronic HCV was 1.88 (95% CI 1.41-2.51) times that among women without HCV, at 2 years, the ratio was 1.60 (95% CI 1.17-2.19), and by 6 years there was no difference (1.03; 95% CI 0.60-1.79).
Chronic HCV may negatively impact early HIV viral response to ART. These findings reaffirm the need to test persons with HIV for HCV infection, and increase engagement in HIV care and access to HCV treatment among persons with HIV/HCV coinfection