Browsing by Author "Qadri F"

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Enterotoxigenic Escherichia coli (ETEC) vaccines: Priority activities to enable product development, licensure, and global access.
(2021-Jul-13) Khalil I; Walker R; Porter CK; Muhib F; Chilengi R; Cravioto A; Guerrant R; Svennerholm AM; Qadri F; Baqar S; Kosek M; Kang G; Lanata C; Armah G; Wierzba T; Hasso-Agopsowicz M; Giersing B; Louis Bourgeois A; WHO, Switzerland. Electronic address: ikhalil@uw.edu.; Centre for Infectious Disease Research in Zambia, Zambia.; Christian Medical College Vellore, India.; NMRC, USA.; National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA.; WHO, Switzerland.; Noguchi Memorial Institute for Medical Research, Ghana.; University of Virginia, USA.; University of Gothenburg, Sweden.; Wake Forest School of Medicine, USA.; Universidad Nacional Autónoma de México, Mexico.; Instituto de Investigacion Nutricional, Peru.; icddr, b, Bangladesh.; PATH, USA.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
Diarrhoeal disease attributable to enterotoxigenic Escherichia coli (ETEC) causes substantial morbidity and mortality predominantly in paediatric populations in low- and middle-income countries. In addition to acute illness, there is an increasing appreciation of the long-term consequences of enteric infections, including ETEC, on childhood growth and development. Provision of potable water and sanitation and appropriate clinical care for acute illness are critical to reduce the ETEC burden. However, these interventions are not always practical and may not achieve equitable and sustainable coverage. Vaccination may be the most cost-effective and equitable means of primary prevention; however, additional data are needed to accelerate the investment and guide the decision-making process for ETEC vaccines. First, to understand and quantify the ETEC disease burden, additional data are needed on the association between ETEC infection and physical and cognitive stunting as well as delayed educational attainment. Furthermore, the role of inappropriate or inadequate antibiotic treatment of ETEC-attributable diarrhoea may contribute to the development of antimicrobial resistance (AMR) and needs further elucidation. An ETEC vaccine that mitigates acute diarrhoeal illness and minimizes the longer-term disease manifestations could have significant public health impact and be a cost-effective countermeasure. Herein we review the ETEC vaccine pipeline, led by candidates compatible with the general parameters of the Preferred Product Characteristics (PPC) recently developed by the World Health Organization. Additionally, we have developed an ETEC Vaccine Development Strategy to provide a framework to underpin priority activities for researchers, funders and vaccine manufacturers, with the goal of addressing globally unmet data needs in the areas of research, product development, and policy, as well as commercialization and delivery. The strategy also aims to guide prioritization and co-ordination of the priority activities needed to minimize the timeline to licensure and use of ETEC vaccines, especially in in low- and middle-income countries, where they are most urgently needed.
Estimating the proportion of clinically suspected cholera cases that are true Vibrio cholerae infections: A systematic review and meta-analysis.
(2023-Sep) Wiens KE; Xu H; Zou K; Mwaba J; Lessler J; Malembaka EB; Demby MN; Bwire G; Qadri F; Lee EC; Azman AS; Division of Tropical and Humanitarian Medicine, Geneva University Hospitals, Geneva, Switzerland.; Department of Pathology and Microbiology, University Teaching Hospital, Lusaka, Zambia.; Geneva Centre for Emerging Viral Diseases, Geneva University Hospitals, Geneva, Switzerland.; Department of Biomedical Sciences, School of Health Sciences, University of Zambia, Lusaka, Zambia.; Infectious Diseases Division, International Centre for Diarrhoeal Disease Research Bangladesh (icddr,b), Dhaka, Bangladesh.; Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America.; Carolina Population Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.; Center for Tropical Diseases and Global Health (CTDGH), Université Catholique de Bukavu, Bukavu, Democratic Republic of the Congo.; Division of Public Health Emergency Preparedness and Response, Ministry of Health, Kampala, Uganda.; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America.; Centre for Infectious Disease Research in Zambia (CIDRZ), Lusaka, Zambia.; Department of Epidemiology and Biostatistics, College of Public Health, Temple University, Philadelphia, Pennsylvania, United States of America.
BACKGROUND: Cholera surveillance relies on clinical diagnosis of acute watery diarrhea. Suspected cholera case definitions have high sensitivity but low specificity, challenging our ability to characterize cholera burden and epidemiology. Our objective was to estimate the proportion of clinically suspected cholera that are true Vibrio cholerae infections and identify factors that explain variation in positivity. METHODS AND FINDINGS: We conducted a systematic review of studies that tested ≥10 suspected cholera cases for V. cholerae O1/O139 using culture, PCR, and/or a rapid diagnostic test. We searched PubMed, Embase, Scopus, and Google Scholar for studies that sampled at least one suspected case between January 1, 2000 and April 19, 2023, to reflect contemporary patterns in V. cholerae positivity. We estimated diagnostic test sensitivity and specificity using a latent class meta-analysis. We estimated V. cholerae positivity using a random-effects meta-analysis, adjusting for test performance. We included 119 studies from 30 countries. V. cholerae positivity was lower in studies with representative sampling and in studies that set minimum ages in suspected case definitions. After adjusting for test performance, on average, 52% (95% credible interval (CrI): 24%, 80%) of suspected cases represented true V. cholerae infections. After adjusting for test performance and study methodology, the odds of a suspected case having a true infection were 5.71 (odds ratio 95% CrI: 1.53, 15.43) times higher when surveillance was initiated in response to an outbreak than in non-outbreak settings. Variation across studies was high, and a limitation of our approach was that we were unable to explain all the heterogeneity with study-level attributes, including diagnostic test used, setting, and case definitions. CONCLUSIONS: In this study, we found that burden estimates based on suspected cases alone may overestimate the incidence of medically attended cholera by 2-fold. However, accounting for cases missed by traditional clinical surveillance is key to unbiased cholera burden estimates. Given the substantial variability in positivity between settings, extrapolations from suspected to confirmed cases, which is necessary to estimate cholera incidence rates without exhaustive testing, should be based on local data.
The 2022 Vaccines Against Shigella and Enterotoxigenic Escherichia coli (VASE) Conference: Summary of abstract-based presentations.
(2024-Mar-07) Banerjee S; Barry EM; Baqar S; Louis Bourgeois A; Campo JJ; Choy RKM; Chakraborty S; Clifford A; Deal C; Estrada M; Fleckenstein J; Hasso-Agopsowicz M; Hausdorff W; Khalil I; Maier N; Mubanga C; Platts-Mills JA; Porter C; Qadri F; Simuyandi M; Walker R; White JA; Washington University School of Medicine, United States.; PATH, United States. Electronic address: aclifford@path.org.; Centre for Infectious Disease Research in Zambia, Zambia.; Antigen Discovery, Inc, United States.; PATH, United States; Faculty of Medicine, Université Libre de Bruxelles, Belgium.; ICMR - National Institute of Cholera and Enteric Diseases, India.; PATH, United States.; Naval Medical Research Command, United States.; World Health Organization, Switzerland.; University of Washington, United States.; US National Institutes of Health, United States.; Johns Hopkins University, United States.; Division of Infectious Diseases and International Health, University of Virginia, United States.; ICDDR,B, Bangladesh.; University of Maryland School of Medicine, United States.; CIDRZ; Centre for Infectious Disease Research in Zambia (CIDRZ)
The global nonprofit organization PATH hosted the third Vaccines Against Shigella and Enterotoxigenic Escherichia coli (VASE) Conference in Washington, DC, on November 29 to December 1, 2022. With a combination of plenary sessions and posters, keynote presentations, and breakout workshops, the 2022 VASE Conference featured key updates on research related to the development of vaccines against neglected diarrheal pathogens including Shigella, enterotoxigenic Escherichia coli (ETEC), Campylobacter, and Salmonella. The presentations and discussions highlighted the significant impact of these diarrheal pathogens, particularly on the health of infants and young children in low- and middle-income countries, reflecting the urgent need for the development and licensure of new enteric vaccines. Oral and poster presentations at the VASE Conference explored a range of topics, including: the global burden and clinical presentation of disease, epidemiology, and the impact of interventions; the assessment of the value of vaccines against enteric pathogens; preclinical evaluations of vaccine candidates and models of enteric diseases; vaccine candidates in clinical trials and human challenge models; host parameters and genomics that predict responses to infection and disease; the application of new omics technologies for characterization of emerging pathogens and host responses; novel adjuvants, vaccine delivery platforms, and immunization strategies; and strategies for combination/co-administered vaccines. The conference agenda also featured ten breakout workshop sessions on topics of importance to the enteric vaccine field, which are summarized separately. This article reviews key points and highlighted research presented in each of the plenary conference sessions and poster presentations at the 2022 VASE Conference.