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Khalil I, Anderson JD, Bagamian KH, Baqar S, Giersing B, Hausdorff WP, Marshall C, Porter CK, Walker RI, Bourgeois AL. Vaccine value profile for enterotoxigenic Escherichia coli (ETEC). Vaccine 2023; 41 Suppl 2:S95-S113. [PMID: 37951695 DOI: 10.1016/j.vaccine.2023.02.011] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 11/28/2022] [Accepted: 02/05/2023] [Indexed: 11/14/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is one of the leading bacterial causes of diarrhoea, especially among children in low-resource settings, and travellers and military personnel from high-income countries. WHO's primary strategic goal for ETEC vaccine development is to develop a safe, effective, and affordable ETEC vaccine that reduces mortality and morbidity due to moderate-to-severe diarrhoeal disease in infants and children under 5 years of age in LMICs, as well as the long-term negative health impact on infant physical and cognitive development resulting from infection with this enteric pathogen. An effective ETEC vaccine will also likely reduce the need for antibiotic treatment and help limit the further emergence of antimicrobial resistance bacterial pathogens. The lead ETEC vaccine candidate, ETVAX, has shown field efficacy in travellers and has moved into field efficacy testing in LMIC infants and children. A Phase 3 efficacy study in LMIC infants is projected to start in 2024 and plans for a Phase 3 trial in travellers are under discussion with the U.S. FDA. Licensing for both travel and LMIC indications is projected to be feasible in the next 5-8 years. Given increasing recognition of its negative impact on child health and development in LMICs and predominance as the leading etiology of travellers' diarrhoea (TD), a standalone vaccine for ETEC is more cost-effective than vaccines targeting other TD pathogens, and a viable commercial market also exists. In contrast, combination of an ETEC vaccine with other vaccines for childhood pathogens in LMICs would maximize protection in a more cost-effective manner than a series of stand-alone vaccines. This 'Vaccine Value Profile' (VVP) for ETEC is intended to provide a high-level, holistic assessment of available data to inform the potential public health, economic and societal value of pipeline vaccines and vaccine-like products. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships, and multi-lateral organizations. All contributors have extensive expertise on various elements of the ETEC VVP and collectively aimed to identify current research and knowledge gaps. The VVP was developed using only existing and publicly available information.
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Affiliation(s)
- Ibrahim Khalil
- Department of Global Health, University of Washington, Seattle, WA 98195, USA.
| | - John D Anderson
- Bagamian Scientific Consulting, LLC, Gainesville, FL 32601, USA; Office of Health Affairs, West Virginia University, Morgantown, WV 26505, USA
| | - Karoun H Bagamian
- Bagamian Scientific Consulting, LLC, Gainesville, FL 32601, USA; Department of Environmental and Global Health, University of Florida, Gainesville, FL 32603, USA
| | - Shahida Baqar
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Birgitte Giersing
- Department of Immunization, Vaccines and Biologicals (IVB), World Health Organization (WHO), Geneva, Switzerland
| | - William P Hausdorff
- PATH, Center for Vaccine Innovation and Access, 455 Massachusetts Ave NW, Washington, DC 20001 USA; Faculty of Medicine, Université Libre de Bruxelles, Brussels 1070, Belgium
| | - Caroline Marshall
- Department of Immunization, Vaccines and Biologicals (IVB), World Health Organization (WHO), Geneva, Switzerland
| | - Chad K Porter
- Directorate for DoD Infectious Diseases Research, Naval Medical Research Command, Silver Spring, MD 20190, USA
| | - Richard I Walker
- PATH, Center for Vaccine Innovation and Access, 455 Massachusetts Ave NW, Washington, DC 20001 USA
| | - A Louis Bourgeois
- PATH, Center for Vaccine Innovation and Access, 455 Massachusetts Ave NW, Washington, DC 20001 USA
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Maier N, Grahek SL, Halpern J, Restrepo S, Troncoso F, Shimko J, Torres O, Belkind-Gerson J, Sack DA, Svennerholm AM, Gustafsson B, Sjöstrand B, Carlin N, Bourgeois AL, Porter CK. Efficacy of an Enterotoxigenic Escherichia coli (ETEC) Vaccine on the Incidence and Severity of Traveler's Diarrhea (TD): Evaluation of Alternative Endpoints and a TD Severity Score. Microorganisms 2023; 11:2414. [PMID: 37894071 PMCID: PMC10609384 DOI: 10.3390/microorganisms11102414] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 09/15/2023] [Accepted: 09/20/2023] [Indexed: 10/29/2023] Open
Abstract
The efficacy of an Oral Whole Cell ETEC Vaccine (OEV) against Travelers' Diarrhea (TD) was reexamined using novel outcome and immunologic measures. More specifically, a recently developed disease severity score and alternative clinical endpoints were evaluated as part of an initial validation effort to access the efficacy of a vaccine intervention for the first time in travelers to an ETEC endemic area. A randomized, double-blind, placebo-controlled trial followed travelers to Guatemala or Mexico up to 28 days after arrival in the country following vaccination (two doses two weeks apart) with an ETEC vaccine. Fecal samples were collected upon arrival, departure, and during TD for pathogen identification. Serum was collected in a subset of subjects to determine IgA cholera toxin B subunit (CTB) antibody titers upon their arrival in the country. The ETEC vaccine's efficacy, utilizing a TD severity score and other alternative endpoints, including the relationship between antibody levels and TD risk, was assessed and compared to the per-protocol primary efficacy endpoint. A total of 1435 subjects completed 7-28 days of follow-up and had available data. Vaccine efficacy was higher against more severe (≥5 unformed stools/24 h) ETEC-attributable TD and when accounting for immunologic take (PE ≥ 50%; p < 0.05). The vaccine protected against less severe (3 and 4 unformed stools/24 h) ETEC-attributable TD when accounting for symptom severity or change in activity (PE = 76.3%, p = 0.01). Immunologic take of the vaccine was associated with a reduced risk of infection with ETEC and other enteric pathogens, and with lower TD severity. Clear efficacy was observed among vaccinees with a TD score of ≥4 or ≥5, regardless of immunologic take (PE = 72.0% and 79.0%, respectively, p ≤ 0.03). The vaccine reduced the incidence and severity of ETEC, and this warrants accelerated evaluation of the improved formulation (designated ETVAX), currently undergoing advanced field testing. Subjects with serum IgA titers to CTB had a lower risk of infection with ETEC and Campylobacter jejuni/coli. Furthermore, the TD severity score provided a more robust descriptor of disease severity and should be included as an endpoint in future studies.
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Affiliation(s)
| | - Shannon L. Grahek
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (S.L.G.); (J.H.); (S.R.); (F.T.); (J.S.); (D.A.S.)
| | - Jane Halpern
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (S.L.G.); (J.H.); (S.R.); (F.T.); (J.S.); (D.A.S.)
| | - Suzanne Restrepo
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (S.L.G.); (J.H.); (S.R.); (F.T.); (J.S.); (D.A.S.)
| | - Felipe Troncoso
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (S.L.G.); (J.H.); (S.R.); (F.T.); (J.S.); (D.A.S.)
| | - Janet Shimko
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (S.L.G.); (J.H.); (S.R.); (F.T.); (J.S.); (D.A.S.)
| | - Olga Torres
- Laboratorio Diagnostico Molecular, Guatemala City 01009, Guatemala;
| | | | - David A. Sack
- Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA; (S.L.G.); (J.H.); (S.R.); (F.T.); (J.S.); (D.A.S.)
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, University of Gothenburg, 405 30 Gothenburg, Sweden;
| | - Björn Gustafsson
- Scandinavian Biopharma Holding AB, 171 48 Stockholm, Sweden (B.S.); (N.C.)
| | - Björn Sjöstrand
- Scandinavian Biopharma Holding AB, 171 48 Stockholm, Sweden (B.S.); (N.C.)
| | - Nils Carlin
- Scandinavian Biopharma Holding AB, 171 48 Stockholm, Sweden (B.S.); (N.C.)
| | | | - Chad K. Porter
- Naval Medical Research Command, Silver Spring, MD 20910, USA;
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Sztein MB, Booth JS. Controlled human infectious models, a path forward in uncovering immunological correlates of protection: Lessons from enteric fevers studies. Front Microbiol 2022; 13:983403. [PMID: 36204615 PMCID: PMC9530043 DOI: 10.3389/fmicb.2022.983403] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 08/24/2022] [Indexed: 11/13/2022] Open
Abstract
Enteric infectious diseases account for more than a billion disease episodes yearly worldwide resulting in approximately 2 million deaths, with children under 5 years old and the elderly being disproportionally affected. Enteric pathogens comprise viruses, parasites, and bacteria; the latter including pathogens such as Salmonella [typhoidal (TS) and non-typhoidal (nTS)], cholera, Shigella and multiple pathotypes of Escherichia coli (E. coli). In addition, multi-drug resistant and extensively drug-resistant (XDR) strains (e.g., S. Typhi H58 strain) of enteric bacteria are emerging; thus, renewed efforts to tackle enteric diseases are required. Many of these entero-pathogens could be controlled by oral or parenteral vaccines; however, development of new, effective vaccines has been hampered by lack of known immunological correlates of protection (CoP) and limited knowledge of the factors contributing to protective responses. To fully comprehend the human response to enteric infections, an invaluable tool that has recently re-emerged is the use of controlled human infection models (CHIMs) in which participants are challenged with virulent wild-type (wt) organisms. CHIMs have the potential to uncover immune mechanisms and identify CoP to enteric pathogens, as well as to evaluate the efficacy of therapeutics and vaccines in humans. CHIMs have been used to provide invaluable insights in the pathogenesis, host-pathogen interaction and evaluation of vaccines. Recently, several Oxford typhoid CHIM studies have been performed to assess the role of multiple cell types (B cells, CD8+ T, Tregs, MAIT, Monocytes and DC) during S. Typhi infection. One of the key messages that emerged from these studies is that baseline antigen-specific responses are important in that they can correlate with clinical outcomes. Additionally, volunteers who develop typhoid disease (TD) exhibit higher levels and more activated cell types (e.g., DC and monocytes) which are nevertheless defective in discrete signaling pathways. Future critical aspects of this research will involve the study of immune responses to enteric infections at the site of entry, i.e., the intestinal mucosa. This review will describe our current knowledge of immunity to enteric fevers caused byS. Typhi and S. Paratyphi A, with emphasis on the contributions of CHIMs to uncover the complex immunological responses to these organisms and provide insights into the determinants of protective immunity.
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Affiliation(s)
- Marcelo B. Sztein
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Medicine, University of Maryland School of Medicine, Baltimore, MD, United States
- *Correspondence: Marcelo B. Sztein,
| | - Jayaum S. Booth
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, MD, United States
- Jayaum S. Booth,
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Clarkson KA, Porter CK, Talaat KR, Kapulu MC, Chen WH, Frenck RW, Bourgeois AL, Kaminski RW, Martin LB. Shigella-Controlled Human Infection Models: Current and Future Perspectives. Curr Top Microbiol Immunol 2022. [PMID: 35616717 DOI: 10.1007/82_2021_248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Shigella-controlled human infection models (CHIMs) are an invaluable tool utilized by the vaccine community to combat one of the leading global causes of infectious diarrhea, which affects infants, children and adults regardless of socioeconomic status. The impact of shigellosis disproportionately affects children in low- and middle-income countries (LMICs) resulting in cognitive and physical stunting, perpetuating a cycle that must be halted. Shigella-CHIMs not only facilitate the early evaluation of enteric countermeasures and up-selection of the most promising products but also provide insight into mechanisms of infection and immunity that are not possible utilizing animal models or in vitro systems. The greater understanding of shigellosis obtained in CHIMs builds and empowers the development of new generation solutions to global health issues which are unattainable in the conventional laboratory and clinical settings. Therefore, refining, mining and expansion of safe and reproducible infection models hold the potential to create effective means to end diarrheal disease and associated co-morbidities associated with Shigella infection.
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Affiliation(s)
- Kristen A Clarkson
- Department of Diarrheal Disease Research, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Chad K Porter
- Enteric Disease Department, Naval Medical Research Center, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Kawsar R Talaat
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, 624 North Broadway Street Hampton House, Baltimore, MD, 21205, USA
| | - Melissa C Kapulu
- Department of Biosciences, KEMRI-Wellcome Trust Research Programme, Kilifi County Hospital, Off Bofa Road, Kilifi, 80108, Kenya
| | - Wilbur H Chen
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 West Baltimore Street, Baltimore, MD, 21201, USA
| | - Robert W Frenck
- Cincinnati Children's Hospital Medical Center, 3333 Burnet Avenue, Cincinnati, OH, 45229, USA
| | - A Louis Bourgeois
- PATH Center for Vaccine Innovation and Access, 455 Massachusetts Avenue NW, Washington, DC, 20001, USA
| | - Robert W Kaminski
- Department of Diarrheal Disease Research, Walter Reed Army Institute of Research, 503 Robert Grant Avenue, Silver Spring, MD, 20910, USA
| | - Laura B Martin
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100, Siena, Italy.
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Pavlinac PB, Rogawski McQuade ET, Platts-Mills JA, Kotloff KL, Deal C, Giersing BK, Isbrucker RA, Kang G, Ma LF, MacLennan CA, Patriarca P, Steele D, Vannice KS. Pivotal Shigella Vaccine Efficacy Trials-Study Design Considerations from a Shigella Vaccine Trial Design Working Group. Vaccines (Basel) 2022; 10:489. [PMID: 35455238 PMCID: PMC9032541 DOI: 10.3390/vaccines10040489] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 03/15/2022] [Accepted: 03/17/2022] [Indexed: 01/27/2023] Open
Abstract
Vaccine candidates for Shigella are approaching phase 3 clinical trials in the target population of young children living in low- and middle-income countries. Key study design decisions will need to be made to maximize the success of such trials and minimize the time to licensure and implementation. We convened an ad hoc working group to identify the key aspects of trial design that would meet the regulatory requirements to achieve the desired indication of prevention of moderate or severe shigellosis due to strains included in the vaccine. The proposed primary endpoint of pivotal Shigella vaccine trials is the efficacy of the vaccine against the first episode of acute moderate or severe diarrhea caused by the Shigella strains contained within the vaccine. Moderate or severe shigellosis could be defined by a modified Vesikari score with dysentery and molecular detection of vaccine-preventable Shigella strains. This report summarizes the rationale and current data behind these considerations, which will evolve as new data become available and after further review and consultation by global regulators and policymakers.
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Affiliation(s)
- Patricia B. Pavlinac
- Departments of Global Health and Epidemiology, University of Washington, Seattle, WA 98105, USA
| | | | - James A. Platts-Mills
- Department of Medicine, Infectious Diseases and International Health, University of Virginia, Charlottesville, VA 22908, USA;
| | - Karen L. Kotloff
- Department of Pediatrics, Medicine, Epidemiology, and Public Health, University of Maryland, Baltimore, MD 21201, USA;
| | - Carolyn Deal
- Enteric and Sexually Transmitted Infections Branch, National Institutes of Health, Rockvile, MD 20892, USA;
| | - Birgitte K. Giersing
- Immunization, Vaccines, and Biologicals Department, World Health Organization, 1211 Geneva, Switzerland; (B.K.G.); (R.A.I.)
| | - Richard A. Isbrucker
- Immunization, Vaccines, and Biologicals Department, World Health Organization, 1211 Geneva, Switzerland; (B.K.G.); (R.A.I.)
| | - Gagandeep Kang
- Department of Gastrointestinal Sciences, Christian Medical College, Vellore 632004, Tamil Nadu, India;
| | - Lyou-Fu Ma
- Enteric and Diarrheal Diseases Program Strategy Team, Bill & Melinda Gates Foundation, Seattle, WA 98102, USA; (L.-F.M.); (C.A.M.); (D.S.); (K.S.V.)
| | - Calman A. MacLennan
- Enteric and Diarrheal Diseases Program Strategy Team, Bill & Melinda Gates Foundation, Seattle, WA 98102, USA; (L.-F.M.); (C.A.M.); (D.S.); (K.S.V.)
| | - Peter Patriarca
- Bill & Melinda Gates Medical Research Institute, Cambridge, MA 02139, USA;
| | - Duncan Steele
- Enteric and Diarrheal Diseases Program Strategy Team, Bill & Melinda Gates Foundation, Seattle, WA 98102, USA; (L.-F.M.); (C.A.M.); (D.S.); (K.S.V.)
| | - Kirsten S. Vannice
- Enteric and Diarrheal Diseases Program Strategy Team, Bill & Melinda Gates Foundation, Seattle, WA 98102, USA; (L.-F.M.); (C.A.M.); (D.S.); (K.S.V.)
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Maier N, Riddle MS, Gutiérrez R, Fraser JA, Connor P, Tribble DR, Porter CK. A disease severity scale for the evaluation of vaccine and other preventive or therapeutic interventions for travellers' diarrhoea. J Travel Med 2022; 29:6365136. [PMID: 34490456 PMCID: PMC8763125 DOI: 10.1093/jtm/taab139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/09/2021] [Accepted: 08/16/2021] [Indexed: 11/14/2022]
Abstract
BACKGROUND Travellers' diarrhoea (TD) is the most common travel-related illness with an estimated 10 million people afflicted annually. Outcome measures to assess the efficacy of primary and secondary TD interventions were historically based on diarrhoea frequency with ≥1 associated gastrointestinal symptom. Furthermore, efficacy determination is often made on the presence or absence of TD, rather than on TD illness severity. Current severity classifications are based on subjective consideration of impact of illness on activity. We sought to develop a standardized scoring system to characterize TD severity to potentially apply as a secondary outcome in future field studies. METHODS Data on multiple signs and symptoms were obtained from a previously published multisite TD treatment trial conducted by the US Department of Defense (TrEAT TD). Correlation, regression and multiple correspondence analyses were performed to assess impact on activity and a TD severity score was established. RESULTS Numerous signs and symptoms were associated with impaired function, with malaise and nausea most strongly associated [odds ratio (OR) 5.9-44.3, P < 0.0001 and OR 2.8-37.1, P < 0.0001, respectively). Based on co-varying symptomatology, a TD severity score accounting for diarrhoea frequency in addition to several signs and symptoms was a better predictor of negative impact on function than any single sign/symptom (X2 = 127.16, P < 0.001). Additionally, there was a significant difference (P < 0.0001) in the mean TD severity score between those with acute watery diarrhoea (3.9 ± 1.9) and those with dysentery or acute febrile illness (6.2 ± 2.0). CONCLUSIONS The newly developed disease severity score better predicted a negative impact on activity due to TD than did any single sign or symptom. Incorporating multiple parameters into the TD severity score better captures illness severity and moves the field towards current recommendations for TD management by considering symptoms with high functional impact. Further validation of this score is needed in non-military travellers and other settings.
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Porter CK, Talaat KR, Isidean SD, Kardinaal A, Chakraborty S, Gutiérrez RL, Sack DA, Bourgeois AL. The Controlled Human Infection Model for Enterotoxigenic Escherichia coli. Curr Top Microbiol Immunol 2021. [PMID: 34669040 DOI: 10.1007/82_2021_242] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The controlled human infection model (CHIM) for enterotoxigenic Escherichia coli (ETEC) has been instrumental in defining ETEC as a causative agent of acute watery diarrhea, providing insights into disease pathogenesis and resistance to illness, and enabling preliminary efficacy evaluations for numerous products including vaccines, immunoprophylactics, and drugs. Over a dozen strains have been evaluated to date, with a spectrum of clinical signs and symptoms that appear to replicate the clinical illness seen with naturally occurring ETEC. Recent advancements in the ETEC CHIM have enhanced the characterization of clinical, immunological, and microbiological outcomes. It is anticipated that omics-based technologies applied to ETEC CHIMs will continue to broaden our understanding of host-pathogen interactions and facilitate the development of primary and secondary prevention strategies.
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Affiliation(s)
- Chad K Porter
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, 20910, USA.
| | - Kawsar R Talaat
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Sandra D Isidean
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, 20910, USA
- Henry M. Jackson Foundation, Bethesda, MD, 20817, USA
| | - Alwine Kardinaal
- NIZO Food Research, Ede, P.O. Box 20, 6710 BA EDE, Kernhemseweg 2, 6718 ZB EDE, The Netherlands
| | - Subhra Chakraborty
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - Ramiro L Gutiérrez
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, 20910, USA
| | - David A Sack
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, 615 N. Wolfe Street, Baltimore, MD, 21205, USA
| | - A Louis Bourgeois
- PATH|Center for Vaccine Innovation and Access, 455 Massachusetts Avenue NW, Suite 1000, Washington, DC, 20001, USA
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Pavlinac PB, Platts-Mills JA, Tickell KD, Liu J, Juma J, Kabir F, Nkeze J, Okoi C, Operario DJ, Uddin J, Ahmed S, Alonso PL, Antonio M, Becker SM, Breiman RF, Faruque ASG, Fields B, Gratz J, Haque R, Hossain A, Hossain MJ, Jarju S, Qamar F, Iqbal NT, Kwambana B, Mandomando I, McMurry TL, Ochieng C, Ochieng JB, Ochieng M, Onyango C, Panchalingam S, Kalam A, Aziz F, Qureshi S, Ramamurthy T, Roberts JH, Saha D, Sow SO, Stroup SE, Sur D, Tamboura B, Taniuchi M, Tennant SM, Roose A, Toema D, Wu Y, Zaidi A, Nataro JP, Levine MM, Houpt ER, Kotloff KL. The Clinical Presentation of Culture-positive and Culture-negative, Quantitative Polymerase Chain Reaction (qPCR)-Attributable Shigellosis in the Global Enteric Multicenter Study and Derivation of a Shigella Severity Score: Implications for Pediatric Shigella Vaccine Trials. Clin Infect Dis 2021; 73:e569-e579. [PMID: 33044509 PMCID: PMC8326551 DOI: 10.1093/cid/ciaa1545] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 10/08/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Shigella is a leading cause of childhood diarrhea and target for vaccine development. Microbiologic and clinical case definitions are needed for pediatric field vaccine efficacy trials. METHODS We compared characteristics of moderate to severe diarrhea (MSD) cases in the Global Enteric Multicenter Study (GEMS) between children with culture positive Shigella to those with culture-negative, quantitative polymerase chain reaction (qPCR)-attributable Shigella (defined by an ipaH gene cycle threshold <27.9). Among Shigella MSD cases, we determined risk factors for death and derived a clinical severity score. RESULTS Compared to culture-positive Shigella MSD cases (n = 745), culture-negative/qPCR-attributable Shigella cases (n = 852) were more likely to be under 12 months, stunted, have a longer duration of diarrhea, and less likely to have high stool frequency or a fever. There was no difference in dehydration, hospitalization, or severe classification from a modified Vesikari score. Twenty-two (1.8%) Shigella MSD cases died within the 14-days after presentation to health facilities, and 59.1% of these deaths were in culture-negative cases. Age <12 months, diarrhea duration prior to presentation, vomiting, stunting, wasting, and hospitalization were associated with mortality. A model-derived score assigned points for dehydration, hospital admission, and longer diarrhea duration but was not significantly better at predicting 14-day mortality than a modified Vesikari score. CONCLUSIONS A composite severity score consistent with severe disease or dysentery may be a pragmatic clinical endpoint for severe shigellosis in vaccine trials. Reliance on culture for microbiologic confirmation may miss a substantial number of Shigella cases but is currently required to measure serotype specific immunity.
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Affiliation(s)
- Patricia B Pavlinac
- Department of Global Health, University of Washington, Seattle, Washington,USA
- Correspondence: Patricia B. Pavlinac, University of Washington, Seattle, WA, United States ()
| | - James A Platts-Mills
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Kirkby D Tickell
- Department of Global Health, University of Washington, Seattle, Washington,USA
| | - Jie Liu
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Jane Juma
- Center for Global Health Research, Kenya Medical Research Institute (KEMRI), Kenya
| | - Furqan Kabir
- Department of Paediatrics and Child Health, Aga Khan University, Karachi,Pakistan
| | - Joseph Nkeze
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland,USA
| | - Catherine Okoi
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul,The Gambia
| | - Darwin J Operario
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Jashim Uddin
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Shahnawaz Ahmed
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B), Dhaka,Bangladesh
| | - Pedro L Alonso
- Barcelona Centre for International Health Research (CRESIB), Hospital Clínic, Universitat de Barcelona, Barcelona,Spain
- Centro de Investigação em Saúde da Manhiça, Maputo,Mozambique
| | - Martin Antonio
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul,The Gambia
| | - Stephen M Becker
- Science Applications International Corporation (SAIC), Richmond, Virginia,USA
| | - Robert F Breiman
- Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, Georgia, USA
| | - Abu S G Faruque
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B), Dhaka,Bangladesh
| | - Barry Fields
- Global Disease Detection Division, Kenya Office of the US Centers for Disease Control and Prevention, Nairobi,Kenya
| | - Jean Gratz
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Rashidul Haque
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B), Dhaka,Bangladesh
| | - Anowar Hossain
- International Centre for Diarrhoeal Disease Research, Bangladesh (ICDDR, B), Dhaka,Bangladesh
| | - M Jahangir Hossain
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul,The Gambia
| | - Sheikh Jarju
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul,The Gambia
| | - Farah Qamar
- Department of Paediatrics and Child Health, Aga Khan University, Karachi,Pakistan
| | - Najeeha Talat Iqbal
- Department of Paediatrics and Child Health, Aga Khan University, Karachi,Pakistan
| | - Brenda Kwambana
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul,The Gambia
| | | | - Timothy L McMurry
- Public Health Sciences, University of Virginia, Charlottesville, Virginia,USA
| | - Caroline Ochieng
- Center for Global Health Research, Kenya Medical Research Institute (KEMRI), Kenya
| | - John B Ochieng
- Center for Global Health Research, Kenya Medical Research Institute (KEMRI), Kenya
| | - Melvin Ochieng
- Center for Global Health Research, Kenya Medical Research Institute (KEMRI), Kenya
| | - Clayton Onyango
- Global Disease Detection Division, Kenya Office of the US Centers for Disease Control and Prevention, Nairobi,Kenya
| | - Sandra Panchalingam
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland,USA
| | - Adil Kalam
- Department of Paediatrics and Child Health, Aga Khan University, Karachi,Pakistan
| | - Fatima Aziz
- Department of Paediatrics and Child Health, Aga Khan University, Karachi,Pakistan
| | - Shahida Qureshi
- Department of Paediatrics and Child Health, Aga Khan University, Karachi,Pakistan
| | | | - James H Roberts
- Public Health Sciences, University of Virginia, Charlottesville, Virginia,USA
| | - Debasish Saha
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Banjul,The Gambia
| | - Samba O Sow
- Centre pour le Développement des Vaccins, Bamako,Mali
| | - Suzanne E Stroup
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Dipika Sur
- National Institute of Cholera and Enteric Diseases, Kolkata,India
| | | | - Mami Taniuchi
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Sharon M Tennant
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland,USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland,USA
| | - Anna Roose
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland,USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland,USA
| | - Deanna Toema
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland,USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland,USA
| | - Yukun Wu
- Sanofi Pasteur, Swiftwater, Pennsylvania,USA
| | - Anita Zaidi
- Bill and Melinda Gates Foundation, Seattle, Washington,USA
| | - James P Nataro
- Public Health Sciences, University of Virginia, Charlottesville, Virginia,USA
| | - Myron M Levine
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland,USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland,USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland,USA
| | - Eric R Houpt
- Division of Infectious Diseases and International Health, University of Virginia, Charlottesville, Virginia,USA
| | - Karen L Kotloff
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland,USA
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland,USA
- Department of Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland,USA
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9
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Bekeredjian-Ding I. Challenges for Clinical Development of Vaccines for Prevention of Hospital-Acquired Bacterial Infections. Front Immunol 2020; 11:1755. [PMID: 32849627 PMCID: PMC7419648 DOI: 10.3389/fimmu.2020.01755] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Accepted: 06/30/2020] [Indexed: 12/19/2022] Open
Abstract
Increasing antibiotic resistance in bacteria causing endogenous infections has entailed a need for innovative approaches to therapy and prophylaxis of these infections and raised a new interest in vaccines for prevention of colonization and infection by typically antibiotic resistant pathogens. Nevertheless, there has been a long history of failures in late stage clinical development of this type of vaccines, which remains not fully understood. This article provides an overview on present and past vaccine developments targeting nosocomial bacterial pathogens; it further highlights the specific challenges associated with demonstrating clinical efficacy of these vaccines and the facts to be considered in future study designs. Notably, these vaccines are mainly applied to subjects with preexistent immunity to the target pathogen, transient or chronic immunosuppression and ill-defined microbiome status. Unpredictable attack rates and changing epidemiology as well as highly variable genetic and immunological strain characteristics complicate the development. In views of the clinical need, re-thinking of the study designs and expectations seems warranted: first of all, vaccine development needs to be footed on a clear rationale for choosing the immunological mechanism of action and the optimal time point for vaccination, e.g., (1) prevention (or reduction) of colonization vs. prevention of infection and (2) boosting of a preexistent immune response vs. altering the quality of the immune response. Furthermore, there are different, probably redundant, immunological and microbiological defense mechanisms that provide protection from infection. Their interplay is not well-understood but as a consequence their effect might superimpose vaccine-mediated resolution of infection and lead to failure to demonstrate efficacy. This implies that improved characterization of patient subpopulations within the trial population should be obtained by pro- and retrospective analyses of trial data on subject level. Statistical and systems biology approaches could help to define immune and microbiological biomarkers that discern populations that benefit from vaccination from those where vaccines might not be effective.
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Affiliation(s)
- Isabelle Bekeredjian-Ding
- Division of Microbiology, Langen, Germany.,Institute for Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Bonn, Germany
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10
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Ndungo E, Pasetti MF. Functional antibodies as immunological endpoints to evaluate protective immunity against Shigella. Hum Vaccin Immunother 2019; 16:197-205. [PMID: 31287754 PMCID: PMC7670857 DOI: 10.1080/21645515.2019.1640427] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The development, clinical advancement and licensure of vaccines, and monitoring of vaccine effectiveness could be expedited and simplified by the ability to measure immunological endpoints that can predict a favorable clinical outcome. Antigen-specific and functional antibodies have been described in the context of naturally acquired immunity and vaccination against Shigella, and their presence in serum has been associated with reduced risk of disease in human subjects. The relevance of these antibodies as correlates of protective immunity, their mechanistic contribution to protection (e.g. target antigens, interference with pathogenesis, and participation in microbial clearance), and factors that influence their magnitude and makeup (e.g. host age, health condition, and environment) are important considerations that need to be explored. In addition to facilitating vaccine evaluation, immunological correlates of protection could be useful for identifying groups at risk and advancing immune therapies. Herein we discuss the precedent and value of functional antibodies as immunological endpoints to predict vaccine efficacy and the relevance of functional antibody activity to evaluate protective immunity against shigellosis.
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Affiliation(s)
- Esther Ndungo
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Marcela F Pasetti
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA
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