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Hasso-Agopsowicz M, Sparrow E, Cameron AM, Sati H, Srikantiah P, Gottlieb S, Bentsi-Enchill A, Le Doare K, Hamel M, Giersing BK, Hausdorff WP. The role of vaccines in reducing antimicrobial resistance: A review of potential impact of vaccines on AMR and insights across 16 vaccines and pathogens. Vaccine 2024; 42:S1-S8. [PMID: 38876836 DOI: 10.1016/j.vaccine.2024.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 05/01/2024] [Accepted: 06/04/2024] [Indexed: 06/16/2024]
Abstract
In 2019, an estimated 4.95 million deaths were linked to antimicrobial resistance (AMR). Vaccines can prevent many of these deaths by averting both drug-sensitive and resistant infections, reducing antibiotic usage, and lowering the likelihood of developing resistance genes. However, their role in mitigating AMR is currently underutilized. This article builds upon previous research that utilizes Vaccine Value Profiles-tools that assess the health, socioeconomic, and societal impact of pathogens-to inform vaccine development. We analyze the effects of 16 pathogens, covered by Vaccine Value Profiles, on AMR, and explore how vaccines could reduce AMR. The article also provides insights into vaccine development and usage. Vaccines are crucial in lessening the impact of infectious diseases and curbing the development of AMR. To fully realize their potential, vaccines must be more prominently featured in the overall strategy to combat AMR. This requires ongoing investment in research and development of new vaccines and the implementation of additional prevention and control measures to address this global threat effectively.
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Affiliation(s)
- Mateusz Hasso-Agopsowicz
- Vaccine Product & Delivery Research, Department of Immunization, Vaccines & Biologicals, World Health Organization, Geneva, Switzerland.
| | - Erin Sparrow
- Vaccine Product & Delivery Research, Department of Immunization, Vaccines & Biologicals, World Health Organization, Geneva, Switzerland
| | - Alexandra Meagan Cameron
- Global Coordination and Partnership (GCP), Antimicrobial Resistance Division, World Health Organization, Geneva, Switzerland
| | - Hatim Sati
- Global Coordination and Partnership (GCP), Antimicrobial Resistance Division, World Health Organization, Geneva, Switzerland
| | | | - Sami Gottlieb
- Department of Sexual and Reproductive Health and Research, World Health Organization, Geneva, Switzerland
| | - Adwoa Bentsi-Enchill
- Vaccine Product & Delivery Research, Department of Immunization, Vaccines & Biologicals, World Health Organization, Geneva, Switzerland
| | | | - Mary Hamel
- Vaccine Product & Delivery Research, Department of Immunization, Vaccines & Biologicals, World Health Organization, Geneva, Switzerland
| | - Birgitte K Giersing
- Vaccine Product & Delivery Research, Department of Immunization, Vaccines & Biologicals, World Health Organization, Geneva, Switzerland
| | - William P Hausdorff
- Center for Vaccine Access and Innovation, PATH, WA DC, USA; Université Libre de Bruxelles, Brussels, Belgium
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2
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von Mentzer A, Svennerholm AM. Colonization factors of human and animal-specific enterotoxigenic Escherichia coli (ETEC). Trends Microbiol 2024; 32:448-464. [PMID: 38052687 DOI: 10.1016/j.tim.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 11/01/2023] [Accepted: 11/07/2023] [Indexed: 12/07/2023]
Abstract
Colonization factors (CFs) are major virulence factors of enterotoxigenic Escherichia coli (ETEC). This pathogen is among the most common causes of bacterial diarrhea in children in low- and middle-income countries, travelers, and livestock. CFs are major candidate antigens in vaccines under development as preventive measures against ETEC infections in humans and livestock. Recent molecular studies have indicated that newly identified CFs on human ETEC are closely related to animal ETEC CFs. Increased knowledge of pathogenic mechanisms, immunogenicity, regulation, and expression of ETEC CFs, as well as the possible spread of animal ETEC to humans, may facilitate the future development of ETEC vaccines for humans and animals. Here, we present an updated review of CFs in ETEC.
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Affiliation(s)
- Astrid von Mentzer
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Sweden; Wellcome Sanger Institute, Hinxton, UK.
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Sweden
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3
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Zhang C, Li S, Upadhyay I, Lauder KL, Sack DA, Zhang W. MecVax supplemented with CFA MEFA-II induces functional antibodies against 12 adhesins (CFA/I, CS1-CS7, CS12, CS14, CS17, and CS21) and 2 toxins (STa, LT) of enterotoxigenic Escherichia coli (ETEC). Microbiol Spectr 2024; 12:e0415323. [PMID: 38364078 PMCID: PMC10986561 DOI: 10.1128/spectrum.04153-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 01/24/2024] [Indexed: 02/18/2024] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains that produce various adhesins and one or two enterotoxins are the leading causes of children's diarrhea and travelers' diarrhea. MecVax, a multivalent ETEC vaccine candidate, consists of two proteins, an adhesin multiepitope fusion antigen (MEFA) that stimulates antibodies to the seven most important ETEC adhesins (CFA/I and CS1-CS6) and a toxoid fusion antigen which stimulates antibodies against ETEC enterotoxins (heat-labile toxin and heat-stable toxin). CFA MEFA-II, another polyvalent MEFA protein, has been demonstrated to stimulate antibodies to another five important ETEC adhesins (CS7, CS12, CS14, CS17, and CS21). We hypothesize that MecVax coverage and efficacy can be expanded if MecVax could stimulate antibodies to all 12 adhesins. In this study, we supplemented MecVax with CFA MEFA-II, examined broad immunity to the 12 targeted ETEC adhesins and 2 ETEC toxins (STa, LT) in mice, and assessed mouse antibody functions for inhibiting the adherence of the 12 adhesins and neutralizing the enterotoxicity of 2 toxins, thus assessing the potential application of a broadly protective pan-ETEC vaccine. Mice intramuscularly immunized with MecVax and CFA MEFA-II developed robust antibody responses to the 12 ETEC adhesins and 2 toxins; furthermore, mouse serum antibodies showed functional activities against the adherence from each of the targeted adhesins and the enterotoxicity of either toxin. Data also indicated that CFA MEFA-II was antigenically compatible with MecVax. These results demonstrated that the inclusion of CFA MEFA-II further expands MecVax broad immunogenicity and protection coverage, suggesting the feasibility of developing a vaccine against all important diarrheal ETEC strains.IMPORTANCEThere are no vaccines licensed for Enterotoxigenic Escherichia coli (ETEC), a leading cause of children's diarrhea and the most common cause of travelers' diarrhea. Since ETEC strains produce over 25 adhesins and 2 distinctive enterotoxins, heterogeneity is a key obstacle to vaccine development. MecVax, a multivalent ETEC vaccine candidate, induces protective antibodies against the seven most important adhesins (CFA/I and CS1-CS6) associated with two-thirds of ETEC clinical cases. However, ETEC prevalence shifts chronically and geographically, and other adhesins are also associated with clinical cases. MecVax would become a pan-ETEC vaccine if it also protects against the remaining important adhesins. This study demonstrated that MecVax supplemented with adhesin protein CFA MEFA-II induces functional antibodies against 12 important ETEC adhesins (CFA/I, CS1-CS7, CS12, CS14, CS17, and CS21), enabling the development of a more broadly protective ETEC vaccine and further validating the application of the MEFA vaccinology platform for multivalent vaccine development.
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Affiliation(s)
- Chongyang Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Siqi Li
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Ipshita Upadhyay
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kathyrn L. Lauder
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - David A. Sack
- Department of International Health, Johns Hopkins University Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Weiping Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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4
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Chakraborty S, Johura FT, Sultana M, Zhang X, Sadique A, George CM, Monira S, Sack DA, Sack RB, Alam M. Epidemiology of Enterotoxigenic Escherichia coli among Children and Adults Seeking Care at Hospitals in Two Geographically Distinct Rural Areas in Bangladesh. Microorganisms 2024; 12:359. [PMID: 38399763 PMCID: PMC10891752 DOI: 10.3390/microorganisms12020359] [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] [Received: 12/21/2023] [Revised: 02/01/2024] [Accepted: 02/03/2024] [Indexed: 02/25/2024] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) infections undeniably continue to have substantial morbidity and mortality in younger children; however, limited data are available on the disease burden of older children and adults and on ETEC epidemiology by geographical location at the subnational level. Facility-based surveillance over the years was established to identify patients with ETEC diarrhea in two geographically distinct areas in rural Bangladesh, Chhatak in the north and Mathbaria in the southern coastal area. ETEC was highly prevalent in both areas, while the proportions, toxin types and colonization factors varied by location, season and age groups. Children < 5 years old and adults between 20 and 60 years old were at the highest risk of ETEC diarrhea which required urgent care. This study underscores the importance of capturing subnational and seasonal variations in ETEC epidemiology. ETEC vaccine developers and public health stakeholders may need to target adults between 20 and 60 years of age in addition to young children as new vaccines currently under development become licensed and introduction begins.
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Affiliation(s)
- Subhra Chakraborty
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.-T.J.); (X.Z.); (C.M.G.); (D.A.S.); (R.B.S.)
| | - Fatema-Tuz Johura
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.-T.J.); (X.Z.); (C.M.G.); (D.A.S.); (R.B.S.)
- International Centre for Diarrhoeal Disease Research, Dhaka 1212, Bangladesh; (M.S.); (A.S.); (S.M.); (M.A.)
| | - Marzia Sultana
- International Centre for Diarrhoeal Disease Research, Dhaka 1212, Bangladesh; (M.S.); (A.S.); (S.M.); (M.A.)
| | - Xueyan Zhang
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.-T.J.); (X.Z.); (C.M.G.); (D.A.S.); (R.B.S.)
| | - Abdus Sadique
- International Centre for Diarrhoeal Disease Research, Dhaka 1212, Bangladesh; (M.S.); (A.S.); (S.M.); (M.A.)
| | - Christine M. George
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.-T.J.); (X.Z.); (C.M.G.); (D.A.S.); (R.B.S.)
| | - Shirajum Monira
- International Centre for Diarrhoeal Disease Research, Dhaka 1212, Bangladesh; (M.S.); (A.S.); (S.M.); (M.A.)
| | - David A. Sack
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.-T.J.); (X.Z.); (C.M.G.); (D.A.S.); (R.B.S.)
| | - Richard Bradley Sack
- Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD 21205, USA; (F.-T.J.); (X.Z.); (C.M.G.); (D.A.S.); (R.B.S.)
| | - Munirul Alam
- International Centre for Diarrhoeal Disease Research, Dhaka 1212, Bangladesh; (M.S.); (A.S.); (S.M.); (M.A.)
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5
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Hossain MJ, Svennerholm AM, Carlin N, D’Alessandro U, Wierzba TF. A Perspective on the Strategy for Advancing ETVAX ®, An Anti-ETEC Diarrheal Disease Vaccine, into a Field Efficacy Trial in Gambian Children: Rationale, Challenges, Lessons Learned, and Future Directions. Microorganisms 2023; 12:90. [PMID: 38257916 PMCID: PMC10819518 DOI: 10.3390/microorganisms12010090] [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] [Received: 11/15/2023] [Revised: 12/22/2023] [Accepted: 12/23/2023] [Indexed: 01/24/2024] Open
Abstract
For the first time in over 20 years, an Enterotoxigenic Escherichia coli (ETEC) vaccine candidate, ETVAX®, has advanced into a phase 2b field efficacy trial for children 6-18 months of age in a low-income country. ETVAX® is an inactivated whole cell vaccine that has gone through a series of clinical trials to provide a rationale for the design elements of the Phase 2b trial. This trial is now underway in The Gambia and will be a precursor to an upcoming pivotal phase 3 trial. To reach this point, numerous findings were brought together to define factors such as safe and immunogenic doses for children, and the possible benefit of a mucosal adjuvant, double mutant labile toxin (dmLT). Considering the promising but still underexplored potential of inactivated whole cells in oral vaccination, we present a perspective compiling key observations from past ETVAX® trials that informed The Gambian trial design. This report will update the trial's status and explore future directions for ETEC vaccine trials. Our aim is to provide not only an update on the most advanced ETEC vaccine candidate but also to offer insights beneficial for the development of other much-needed oral whole-cell vaccines against enteric and other pathogens.
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Affiliation(s)
- M. Jahangir Hossain
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Banjul P.O. Box 273, The Gambia
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Gothenburg University Research Institute (GUVAX), Gothenburg University, 40530 Gothenburg, Sweden
| | - Nils Carlin
- Scandinavian Biopharma, Industrivägen 1, 17148 Solna, Sweden
| | - Umberto D’Alessandro
- Medical Research Council Unit The Gambia at the London School of Hygiene and Tropical Medicine, Fajara, Banjul P.O. Box 273, The Gambia
| | - Thomas F. Wierzba
- Section on Infectious Diseases, Department of Internal Medicine, Wake Forest School of Medicine, Winston Salem, NC 27157, USA
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6
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Upadhyay I, Parvej SMD, Shen Y, Li S, Lauder KL, Zhang C, Zhang W. Protein-based vaccine candidate MecVax broadly protects against enterotoxigenic Escherichia coli intestinal colonization in a rabbit model. Infect Immun 2023; 91:e0027223. [PMID: 37874163 PMCID: PMC10652908 DOI: 10.1128/iai.00272-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/20/2023] [Indexed: 10/25/2023] Open
Abstract
There are no vaccines licensed against enterotoxigenic Escherichia coli (ETEC), a leading cause of children's diarrhea and the most common cause of travelers' diarrhea. Multivalent vaccine candidate MecVax unprecedentedly targets two ETEC enterotoxins (heat-stable toxin, STa; heat-labile toxin, LT) and the seven most prevalent ETEC adhesins (colonization factor antigen, CFA/I, coli surface antigens, CS1-CS6) and has been demonstrated preclinically to protect against STa- and LT-mediated ETEC clinical diarrhea and prevent intestinal colonization from ETEC strain H10407 (CFA/I, STa, LT). However, it is unattested whether MecVax broadly protects against intestinal colonization from ETEC strains producing the other six adhesins (CS1-CS6) also targeted by this product. In this study, we immunized rabbits with MecVax and challenged them with heterogeneous ETEC strains that express CS1-CS6 adhesins to evaluate MecVax's efficacy against bacterial intestinal colonization, thus providing broad vaccine protection against ETEC infection. Data revealed that rabbits intramuscularly immunized with MecVax developed robust responses to both ETEC enterotoxins (STa, LT) and seven adhesins (CFA/I, CS1-CS6), and when challenged with ETEC isolates expressing CS1/CS3, CS2/CS3, CS4/CS6, CS5/CS6, or CS6 adhesin, the immunized rabbits prevented over two logs (>99%) of bacteria from colonization in small intestines. Additionally, compared to a CFA-toxoid fusion protein, which is another potential ETEC vaccine antigen to target two ETEC enterotoxins and the seven adhesins, MecVax exhibited better protection against ETEC intestinal colonization. These results, in conjunction with the protection data from early studies, evidenced that MecVax is broadly protective, validating MecVax's candidacy as an effective vaccine against ETEC-associated diarrhea and accelerating ETEC vaccine development.
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Affiliation(s)
- Ipshita Upadhyay
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Shafiullah M. D. Parvej
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yiyang Shen
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Siqi Li
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Kathryn L. Lauder
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Chongyang Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Weiping Zhang
- Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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7
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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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8
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Sukwa N, Mubanga C, Hatyoka LM, Chilyabanyama ON, Chibuye M, Mundia S, Munyinda M, Kamuti E, Siyambango M, Badiozzaman S, Bosomprah S, Carlin N, Kaim J, Sjöstrand B, Simuyandi M, Chilengi R, Svennerholm AM. Safety, tolerability, and immunogenicity of an oral inactivated ETEC vaccine (ETVAX®) with dmLT adjuvant in healthy adults and children in Zambia: An age descending randomised, placebo-controlled trial. Vaccine 2023; 41:6884-6894. [PMID: 37838479 DOI: 10.1016/j.vaccine.2023.09.052] [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: 02/13/2023] [Revised: 08/07/2023] [Accepted: 09/23/2023] [Indexed: 10/16/2023]
Abstract
BACKGROUND Enterotoxigenic Escherichia coli (ETEC) is an important cause of moderate to severe diarrhoea in children for which there is no licensed vaccine. We evaluated ETVAX®, an oral, inactivated ETEC vaccine containing four E. coli strains over-expressing the major colonization factors CFA/I, CS3, CS5, and CS6, a toxoid (LCTBA) and double mutant heat-labile enterotoxin (dmLT) adjuvant for safety, tolerability, and immunogenicity. METHODS A double-blind, placebo-controlled, age-descending, dose-finding trial was undertaken in 40 adults, 60 children aged 10-23 months, and 146 aged 6-9 months. Adults received one full dose of ETVAX® and children received 3 doses of either 1/4 or 1/8 dose. Safety was evaluated as solicited and unsolicited events for 7 days following vaccination. Immunogenicity was assessed by evaluation of plasma IgA antibody responses to CFA/I, CS3, CS5, CS6, and LTB, and IgG responses to LTB. RESULTS Solicited adverse events were mostly mild or moderate with only 2 severe fever reports which were unrelated to the vaccine. The most common events were abdominal pain in adults (26.7 % in vaccinees vs 20 % in placebos), and fever in children aged 6-9 months (44 % vs 54 %). Dosage, number of vaccinations and decreasing age had no influence on severity or frequency of adverse events. The vaccine induced plasma IgA and IgG responses against LTB in 100 % of the adults and 80-90 % of the children. In the 6-23 months cohort, IgA responses to more than 3 vaccine antigens after 3 doses determined as ≥2-fold rise was significantly higher for 1/4 dose compared to placebo (56.7 % vs 27.2 %, p = 0.01). In the 6-9 months cohort, responses to the 1/4 dose were significantly higher than 1/8 dose after 3 rather than 2 doses. CONCLUSION ETVAX® was safe, tolerable, and immunogenic in Zambian adults and children. The 1/4 dose induced significantly stronger IgA responses and is recommended for evaluation of protection in children. CLINICAL TRIALS REGISTRATION The trial is registered with the Pan African Clinical Trials Registry (PACTR Ref. 201905764389804) and a description of this clinical trial is available on: https://pactr.samrc.ac.za/Trial Design.
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Affiliation(s)
- Nsofwa Sukwa
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia.
| | - Cynthia Mubanga
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; Division of Medical Microbiology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, South Africa
| | - Luiza M Hatyoka
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Obvious N Chilyabanyama
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Mwelwa Chibuye
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Samson Mundia
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Masiliso Munyinda
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Ethel Kamuti
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Muyunda Siyambango
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Sharif Badiozzaman
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Samuel Bosomprah
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; Department of Biostatistics, School of Public Health, University of Ghana, Accra, Ghana
| | | | - Joanna Kaim
- Department of Microbiology and Immunology, University of Gothenburg, Sweden
| | | | - Michelo Simuyandi
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Roma Chilengi
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
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9
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Smith EM, Papadimas A, Gabor C, Cooney C, Wu T, Rasko D, Barry EM. The role of the minor colonization factor CS14 in adherence to intestinal cell models by geographically diverse ETEC isolates. mSphere 2023; 8:e0030223. [PMID: 37787523 PMCID: PMC10597352 DOI: 10.1128/msphere.00302-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/15/2023] [Indexed: 10/04/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a primary causative agent of diarrhea in travelers and young children in low- to middle-income countries. ETEC adheres to small intestinal epithelia via colonization factors (CFs) and secretes heat-stable toxin and/or heat-labile toxin, causing dysregulated ion transport and water secretion. There are over 30 CFs identified, including major CFs associated with moderate-to-severe diarrhea (MSD) and minor CFs for which a role in pathogenesis is less clear. The Global Enteric Multicenter Study identified CS14, a class 5a fimbriae, as the only minor CF significantly associated with MSD and was recommended for inclusion in ETEC vaccines. Despite detection of CS14 in ETEC isolates, the sequence conservation of the CS14 operon, its role in adherence, and functional cross-reactivity to other class 5a fimbriae like CFA/I and CS4 are not understood. Sequence analysis determined that the CS14 operon is >99.9% identical among seven geographically diverse isolates with expanded sequence analysis demonstrating SNPs exclusively in the gene encoding the tip adhesin CsuD. Western blots and electron microscopy demonstrated that CS14 expression required the growth of isolates on CFA agar with the iron chelator deferoxamine mesylate. CS14 expression resulted in significantly increased adherence to cultured intestinal cells and human enteroids. Anti-CS14 antibodies and anti-CS4 antibodies, but not anti-CFA/I antibodies, inhibited the adherence of a subset of ETEC isolates, demonstrating CS14-specific inhibition with partial cross-reactivity within the class 5a fimbrial family. These data provide support for CS14 as an important fimbrial CF and its consideration as a vaccine antigen in future strategies. IMPORTANCE Enterotoxigenic Escherichia coli (ETEC) infection causes profuse watery diarrhea in adults and children in low- to middle-income countries and is a leading cause of traveler's diarrhea. Despite increased use of rehydration therapies, young children especially can suffer long-term effects including gastrointestinal dysfunction as well as stunting and malnutrition. As there is no licensed vaccine for ETEC, there remains a need to identify and understand specific antigens for inclusion in vaccine strategies. This study investigated one adhesin named CS14. This adhesin is expressed on the bacterial surface of ETEC isolates and was recently recognized for its significant association with diarrheal disease. We demonstrated that CS14 plays a role in bacterial adhesion to human target cells, a critical first step in the disease process, and that adherence could be blocked by CS14-specific antibodies. This work will significantly impact the ETEC field by supporting inclusion of CS14 as an antigen for ETEC vaccines.
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Affiliation(s)
- Emily M. Smith
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Antonia Papadimas
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Caitlin Gabor
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Ceanna Cooney
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tao Wu
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - David Rasko
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Eileen M. Barry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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10
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Svennerholm AM, Lundgren A. Developments in oral enterotoxigenic Escherichia coli vaccines. Curr Opin Immunol 2023; 84:102372. [PMID: 37523966 DOI: 10.1016/j.coi.2023.102372] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/11/2023] [Accepted: 07/04/2023] [Indexed: 08/02/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea in children in developing countries and in travelers. WHO has affirmed ETEC as a priority vaccine target, but there is no licensed ETEC vaccine available yet. We here describe recent, promising developments of different live, inactivated, and subunit ETEC candidate vaccines expressing or containing nontoxic enterotoxin and/or colonization factor antigens with a focus on oral vaccines. Many of the ETEC candidate vaccines have been tested in clinical trials for safety and immunogenicity and some of them also for protective efficacy in field trials or in challenge studies.
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Affiliation(s)
- Ann-Mari Svennerholm
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden.
| | - Anna Lundgren
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden
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11
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Mubanga C, Simuyandi M, Mwape K, Chibesa K, Chisenga C, Chilyabanyama ON, Randall A, Liang X, Glashoff RH, Chilengi R. Use of an ETEC Proteome Microarray to Evaluate Cross-Reactivity of ETVAX ® Vaccine-Induced IgG Antibodies in Zambian Children. Vaccines (Basel) 2023; 11:vaccines11050939. [PMID: 37243042 DOI: 10.3390/vaccines11050939] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/02/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
Developing a broadly protective vaccine covering most ETEC variants has been elusive. The most clinically advanced candidate yet is an oral inactivated ETEC vaccine (ETVAX®). We report on the use of a proteome microarray for the assessment of cross-reactivity of anti-ETVAX® IgG antibodies against over 4000 ETEC antigens and proteins. We evaluated 40 (pre-and post-vaccination) plasma samples from 20 Zambian children aged 10-23 months that participated in a phase 1 trial investigating the safety, tolerability, and immunogenicity of ETVAX® adjuvanted with dmLT. Pre-vaccination samples revealed high IgG responses to a variety of ETEC proteins including classical ETEC antigens (CFs and LT) and non-classical antigens. Post-vaccination reactivity to CFA/I, CS3, CS6, and LTB was stronger than baseline among the vaccinated compared to the placebo group. Interestingly, we noted significantly high post-vaccination responses to three non-vaccine ETEC proteins: CS4, CS14, and PCF071 (p = 0.043, p = 0.028, and p = 0.00039, respectively), suggestive of cross-reactive responses to CFA/I. However, similar responses were observed in the placebo group, indicating the need for larger studies. We conclude that the ETEC microarray is a useful tool for investigating antibody responses to numerous antigens, especially because it may not be practicable to include all antigens in a single vaccine.
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Affiliation(s)
- Cynthia Mubanga
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia
- Division of Medical Microbiology, Department of Pathology, Stellenbosch University & National Health Laboratory Service, Tygerberg Hospital Francie van Zijl Drive, P.O. Box 241, Cape Town 8000, South Africa
| | - Michelo Simuyandi
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia
| | - Kapambwe Mwape
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia
- Water and Health Research Center, Faculty of Health Sciences, University of Johannesburg, P.O. Box 17011, Doornfontein 2028, South Africa
| | - Kennedy Chibesa
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia
- Division of Virology, School of Pathology, Faculty of Health Sciences, University of the Free State, 205 Nelson Mandela, P.O. Box 339, Bloemfontein 9300, South Africa
| | - Caroline Chisenga
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia
| | | | - Arlo Randall
- Antigen Discovery Inc., 1 Technology Dr., Suite E309, Irvine, CA 92618, USA
| | - Xiaowu Liang
- Antigen Discovery Inc., 1 Technology Dr., Suite E309, Irvine, CA 92618, USA
| | - Richard H Glashoff
- Division of Medical Microbiology, Department of Pathology, Stellenbosch University & National Health Laboratory Service, Tygerberg Hospital Francie van Zijl Drive, P.O. Box 241, Cape Town 8000, South Africa
| | - Roma Chilengi
- Enteric Disease and Vaccine Research Unit, Centre for Infectious Disease Research in Zambia, Lusaka P.O. Box 34681, Zambia
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12
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Ding D, Wang B, Zhang X, Zhang J, Zhang H, Liu X, Gao Z, Yu Z. The spread of antibiotic resistance to humans and potential protection strategies. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 254:114734. [PMID: 36950985 DOI: 10.1016/j.ecoenv.2023.114734] [Citation(s) in RCA: 25] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/26/2023] [Accepted: 03/03/2023] [Indexed: 06/18/2023]
Abstract
Antibiotic resistance is currently one of the greatest threats to human health. Widespread use and residues of antibiotics in humans, animals, and the environment can exert selective pressure on antibiotic resistance bacteria (ARB) and antibiotic resistance gene (ARG), accelerating the flow of antibiotic resistance. As ARG spreads to the population, the burden of antibiotic resistance in humans increases, which may have potential health effects on people. Therefore, it is critical to mitigate the spread of antibiotic resistance to humans and reduce the load of antibiotic resistance in humans. This review briefly described the information of global antibiotic consumption information and national action plans (NAPs) to combat antibiotic resistance and provided a set of feasible control strategies for the transmission of ARB and ARG to humans in three areas including (a) Reducing the colonization capacity of exogenous ARB, (b) Enhancing human colonization resistance and mitigating the horizontal gene transfer (HGT) of ARG, (c) Reversing ARB antibiotic resistance. With the hope of achieving interdisciplinary one-health prevention and control of bacterial resistance.
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Affiliation(s)
- Dong Ding
- The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China; College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Bin Wang
- College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Xiaoan Zhang
- The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Junxi Zhang
- NHC Key Laboratory of Birth Defects Prevention & Henan Key Laboratory of Population Defects Prevention, Zhengzhou, China
| | - Huanhuan Zhang
- College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Xinxin Liu
- College of Public Health, Zhengzhou University, Zhengzhou, China
| | - Zhan Gao
- The Fifth Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
| | - Zengli Yu
- College of Public Health, Zhengzhou University, Zhengzhou, China; The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
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13
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Walker RI, Bourgeois AL. Oral inactivated whole cell vaccine for mucosal immunization: ETVAX case study. Front Immunol 2023; 14:1125102. [PMID: 36936951 PMCID: PMC10018008 DOI: 10.3389/fimmu.2023.1125102] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/03/2023] [Indexed: 03/06/2023] Open
Abstract
Oral immunization is an effective strategy for inducing protective immunity against mucosal enteric pathogens. Although live-attenuated as well as subunit approaches have been explored for vaccination against enteric pathogens, inactivated whole bacterial cells may also be effective in introducing protective immunity. Successfully accomplishing this goal with inactivated whole bacterial cells will require that a complex antigenic repertoire be presented in controlled immunogenic amounts, in a safe and relatively simple and self-contained delivery format. The benefit from immunization with whole cell vaccines can be further enhanced through genetic engineering to over-express selected antigens and also by the use of mucosal adjuvants to direct a more robust immunologic response. These steps are being taken for the development of ETVAX, the most clinically advanced vaccine candidate against the major enteric pathogen, enterotoxigenic Escherichia coli (ETEC) with significant positive impact.
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Affiliation(s)
- Richard I. Walker
- Center for Vaccine Innovation and Access, PATH, Washington, DC, United States
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14
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Pokharel P, Dhakal S, Dozois CM. The Diversity of Escherichia coli Pathotypes and Vaccination Strategies against This Versatile Bacterial Pathogen. Microorganisms 2023; 11:344. [PMID: 36838308 PMCID: PMC9965155 DOI: 10.3390/microorganisms11020344] [Citation(s) in RCA: 27] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023] Open
Abstract
Escherichia coli (E. coli) is a gram-negative bacillus and resident of the normal intestinal microbiota. However, some E. coli strains can cause diseases in humans, other mammals and birds ranging from intestinal infections, for example, diarrhea and dysentery, to extraintestinal infections, such as urinary tract infections, respiratory tract infections, meningitis, and sepsis. In terms of morbidity and mortality, pathogenic E. coli has a great impact on public health, with an economic cost of several billion dollars annually worldwide. Antibiotics are not usually used as first-line treatment for diarrheal illness caused by E. coli and in the case of bloody diarrhea, antibiotics are avoided due to the increased risk of hemolytic uremic syndrome. On the other hand, extraintestinal infections are treated with various antibiotics depending on the site of infection and susceptibility testing. Several alarming papers concerning the rising antibiotic resistance rates in E. coli strains have been published. The silent pandemic of multidrug-resistant bacteria including pathogenic E. coli that have become more difficult to treat favored prophylactic approaches such as E. coli vaccines. This review provides an overview of the pathogenesis of different pathotypes of E. coli, the virulence factors involved and updates on the major aspects of vaccine development against different E. coli pathotypes.
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Affiliation(s)
- Pravil Pokharel
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Sabin Dhakal
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Charles M. Dozois
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
- Pasteur Network, Laval, QC H7V 1B7, Canada
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15
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Zhang Y, Tan P, Zhao Y, Ma X. Enterotoxigenic Escherichia coli: intestinal pathogenesis mechanisms and colonization resistance by gut microbiota. Gut Microbes 2022; 14:2055943. [PMID: 35358002 PMCID: PMC8973357 DOI: 10.1080/19490976.2022.2055943] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and travelers in developing countries. ETEC is characterized by the ability to produce major virulence factors including colonization factors (CFs) and enterotoxins, that bind to specific receptors on epithelial cells and induce diarrhea. The gut microbiota is a stable and sophisticated ecosystem that performs a range of beneficial functions for the host, including protection against pathogen colonization. Understanding the pathogenic mechanisms of ETEC and the interaction between the gut microbiota and ETEC represents not only a research need but also an opportunity and challenge to develop precautions for ETEC infection. Herein, this review focuses on recent discoveries about ETEC etiology, pathogenesis and clinical manifestation, and discusses the colonization resistances mediated by gut microbiota, as well as preventative strategies against ETEC with an aim to provide novel insights that can reduce the adverse effect on human health.
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Affiliation(s)
- Yucheng Zhang
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
| | - Peng Tan
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
| | - Ying Zhao
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
| | - Xi Ma
- State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China,CONTACT Xi Ma State Key Laboratory of Animal Nutrition, Department of Animal Nutrition and Feed Science, China Agricultural University, Beijing, China
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16
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Jones RM, Seo H, Zhang W, Sack DA. A multi-epitope fusion antigen candidate vaccine for Enterotoxigenic Escherichia coli is protective against strain B7A colonization in a rabbit model. PLoS Negl Trop Dis 2022; 16:e0010177. [PMID: 35139116 PMCID: PMC8863229 DOI: 10.1371/journal.pntd.0010177] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 02/22/2022] [Accepted: 01/17/2022] [Indexed: 11/18/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) strains are a leading cause of children's and travelers' diarrhea. Developing effective vaccines against this heterologous group has proven difficult due to the varied nature of toxins and adhesins that determine their pathology. A multivalent candidate vaccine was developed using a multi-epitope fusion antigen (MEFA) vaccinology platform and shown to effectively elicit broad protective antibody responses in mice and pigs. However, direct protection against ETEC colonization of the small intestine was not measured in these systems. Colonization of ETEC strains is known to be a determining factor in disease outcomes and is adhesin-dependent. In this study, we developed a non-surgical rabbit colonization model to study immune protection against ETEC colonization in rabbits. We tested the ability for the MEFA-based vaccine adhesin antigen, in combination with dmLT adjuvant, to induce broad immune responses and to protect from ETEC colonization of the rabbit small intestine. Our results indicate that the candidate vaccine MEFA antigen elicits antibodies in rabbits that react to seven adhesins included in its construction and protects against colonization of a challenge strain that consistently colonized naïve rabbits.
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Affiliation(s)
- Richard M. Jones
- Johns Hopkins Bloomberg School of Public Health, Department of International Health, Baltimore, Maryland, United States of America
- University of Washington, Department of Microbiology, Seattle, Washington, United States of America
- * E-mail:
| | - Hyesuk Seo
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, United States of America
| | - Weiping Zhang
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, United States of America
| | - David A. Sack
- Johns Hopkins Bloomberg School of Public Health, Department of International Health, Baltimore, Maryland, United States of America
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17
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Berzosa M, Nemeskalova A, Calvo A, Quincoces G, Collantes M, Pareja F, Gamazo C, Irache JM. Oral Immunogenicity of Enterotoxigenic Escherichia coli Outer Membrane Vesicles Encapsulated into Zein Nanoparticles Coated with a Gantrez ® AN-Mannosamine Polymer Conjugate. Pharmaceutics 2022; 14:123. [PMID: 35057017 PMCID: PMC8780369 DOI: 10.3390/pharmaceutics14010123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Revised: 12/07/2021] [Accepted: 12/28/2021] [Indexed: 12/24/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) represents a major cause of morbidity and mortality in the human population. In particular, ETEC infections affect children under the age of five from low-middle income countries. However, there is no licensed vaccine against this pathogen. ETEC vaccine development is challenging since this pathotype expresses a wide variety of antigenically diverse virulence factors whose genes can be modified due to ETEC genetic plasticity. To overcome this challenge, we propose the use of outer membrane vesicles (OMVs) isolated from two ETEC clinical strains. In these OMVs, proteomic studies revealed the presence of important immunogens, such as heat-labile toxin, colonization factors, adhesins and mucinases. Furthermore, these vesicles proved to be immunogenic after subcutaneous administration in BALB/c mice. Since ETEC is an enteropathogen, it is necessary to induce both systemic and mucosal immunity. For this purpose, the vesicles, free or encapsulated in zein nanoparticles coated with a Gantrez®-mannosamine conjugate, were administered orally. Biodistribution studies showed that the encapsulation of OMVs delayed the transit through the gut. These results were confirmed by in vivo study, in which OMV encapsulation resulted in higher levels of specific antibodies IgG2a. Further studies are needed to evaluate the protection efficacy of this vaccine approach.
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Affiliation(s)
- Melibea Berzosa
- Department of Microbiology and Parasitology, Institute of Tropical Health, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.C.); (C.G.)
| | - Alzbeta Nemeskalova
- Department of Microbiology and Parasitology, Institute of Tropical Health, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.C.); (C.G.)
- Department of Analytical Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague, Czech Republic
| | - Alba Calvo
- Department of Microbiology and Parasitology, Institute of Tropical Health, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.C.); (C.G.)
| | - Gemma Quincoces
- Department of Nuclear Medicine, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (G.Q.); (M.C.); (F.P.)
| | - María Collantes
- Department of Nuclear Medicine, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (G.Q.); (M.C.); (F.P.)
| | - Felix Pareja
- Department of Nuclear Medicine, Clínica Universidad de Navarra, 31008 Pamplona, Spain; (G.Q.); (M.C.); (F.P.)
| | - Carlos Gamazo
- Department of Microbiology and Parasitology, Institute of Tropical Health, University of Navarra, 31008 Pamplona, Spain; (M.B.); (A.N.); (A.C.); (C.G.)
| | - Juan Manuel Irache
- Department of Pharmacy and Pharmaceutical Technology, University of Navarra, 31008 Pamplona, Spain
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18
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Fleckenstein JM. Confronting challenges to enterotoxigenic Escherichia coli vaccine development. FRONTIERS IN TROPICAL DISEASES 2021; 2:709907. [PMID: 35937717 PMCID: PMC9355458 DOI: 10.3389/fitd.2021.709907] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/02/2023] Open
Abstract
The enterotoxigenic Escherichia coli (ETEC) are a diverse and genetically plastic pathologic variant (pathovar) of E. coli defined by their production of heat-labile (LT) and heat-stable (ST) enterotoxins. These pathogens, which came to recognition more than four decades ago in patients presenting with severe cholera-like diarrhea, are now known to cause hundreds of millions of cases of symptomatic infection annually. Children in low-middle income regions of the world lacking access to clean water and basic sanitation are disproportionately affected by ETEC. In addition to acute diarrheal morbidity, these pathogens remain a significant cause of mortality in children under the age of five years and have also been linked repeatedly to sequelae of childhood malnutrition and growth stunting. Vaccines that could prevent ETEC infections therefore remain a high priority. Despite several decades of effort, a licensed vaccine that protects against the breadth of these pathogens remains an aspirational goal, and the underlying genetic plasticity of E. coli has posed a fundamental challenge to development of a vaccine that can encompass the complete antigenic spectrum of ETEC. Nevertheless, novel strategies that include toxoids, a more complete understanding of ETEC molecular pathogenesis, structural details of target immunogens, and the discovery of more highly conserved antigens essential for virulence should accelerate progress and make a broadly protective vaccine feasible.
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Affiliation(s)
- James M. Fleckenstein
- Department of Medicine, Division of Infectious Diseases, Washington University in Saint Louis, School of Medicine, Saint Louis, Missouri, USA
- Medicine Service, Infectious Diseases, John Cochran Saint Louis Veterans Affairs Health Care System, Saint Louis, Missouri, USA
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19
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Svennerholm AM, Lundgren A, Leach S, Akhtar M, Qadri F. Mucosal immune responses against an oral ETEC vaccine evaluated in clinical trials. J Infect Dis 2021; 224:S821-S828. [PMID: 34550392 PMCID: PMC8687049 DOI: 10.1093/infdis/jiab475] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of mortality and morbidity in children in low-income countries. We have tested an oral ETEC vaccine, ETVAX, consisting of inactivated E coli overexpressing the most prevalent colonization factors and a toxoid, LCTBA, administered together with a mucosal adjuvant, double-mutant heat-labile toxin (dmLT), for capacity to induce mucosal immune responses and immunological memory against the primary vaccine antigens, ie, colonization factors, heat-labile toxin B-subunit and O antigen. The studies show that ETVAX could induce strong intestine-derived and/or fecal immune responses in a majority of vaccinated Swedish adults and in different age groups, including infants, in Bangladesh.
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Affiliation(s)
| | - Anna Lundgren
- Department of Microbiology and Immunology, University of Gothenburg, Sweden
| | - Susannah Leach
- Department of Microbiology and Immunology, University of Gothenburg, Sweden.,Department of Clinical Pharmacology, Sahlgrenska University Hospital, Sweden
| | | | - Firdausi Qadri
- Infectious Diseases Division of icddr,b, Dhaka, Bangladesh
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20
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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. Enterotoxigenic Escherichia coli (ETEC) vaccines: Priority activities to enable product development, licensure, and global access. Vaccine 2021; 39:4266-4277. [PMID: 33965254 PMCID: PMC8273896 DOI: 10.1016/j.vaccine.2021.04.018] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 02/08/2023]
Abstract
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.
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Affiliation(s)
| | | | | | | | - Roma Chilengi
- Centre for Infectious Disease Research in Zambia, Zambia
| | | | | | | | | | - Shahida Baqar
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA
| | | | | | | | - George Armah
- Noguchi Memorial Institute for Medical Research, Ghana
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21
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Von Mentzer A, Zalem D, Chrienova Z, Teneberg S. Colonization factor CS30 from enterotoxigenic Escherichia coli binds to sulfatide in human and porcine small intestine. Virulence 2021; 11:381-390. [PMID: 32245341 PMCID: PMC7161690 DOI: 10.1080/21505594.2020.1749497] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The ability to adhere via colonization factors to specific receptors located on the intestinal mucosa is a key virulence factor in enterotoxigenic Escherichia coli (ETEC) pathogenesis. Here, the potential glycosphingolipid receptors of the novel human ETEC colonization factor CS30 were examined by binding of CS30-expressing bacteria to glycosphingolipids on thin-layer chromatograms. We thereby found a highly specific binding of CS30-expressing bacteria to a fast-migrating acid glycosphingolipid of human and porcine small intestine, while no binding was obtained with a mutant ETEC strain unable to express CS30 fimbriae. The CS30 binding glycosphingolipid from human small intestine was isolated and characterized by mass spectrometry as sulfatide (SO3-3Galβ1Cer). Comparative binding studies using sulfatides with different ceramide compositions gave a preferential binding of CS30 to sulfatide with d18:1-h24:0 ceramide. This ceramide species of sulfatide was also isolated from human small intestine and characterized by mass spectrometry and antibody binding. These studies implicate sulfatide as candidate receptor for mediating attachment of CS30-fimbriated ETEC to human and porcine small intestinal cells. Our findings may be a basis for designing receptor saccharide analogues for inhibition of the intestinal adhesion of CS30-expressing E. coli.
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Affiliation(s)
- Astrid Von Mentzer
- Department of Microbiology and Immunology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Wellcome Sanger Institute: Parasites and Microbes Programme, Hinxton, UK
| | - Dani Zalem
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
| | - Zofia Chrienova
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.,Department of Chemistry, Faculty of Science, University of Hradec Králové, Hradec Králové, Czech Republic
| | - Susann Teneberg
- Department of Medical Biochemistry and Cell Biology, Sahlgrenska Academy, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden
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22
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Sanchez V, Rosales-Mendoza S, Monreal-Escalante E, Murillo-Álvarez JI, Angulo C. Conjugation of β-glucans on heat-stable enterotoxin (ST) to enhance the immunogenic response in mouse leucocytes. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 118:111464. [PMID: 33255046 DOI: 10.1016/j.msec.2020.111464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Revised: 08/22/2020] [Accepted: 08/26/2020] [Indexed: 11/19/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is an important diarrhea-causing pathogen for humans. Heat-stable enterotoxin (ST) plays a crucial role in triggering diarrhea and ETEC pathogenesis. However, ST is a small peptide that lacks immunogenic activity itself but becomes immunogenic when it is coupled to a carrier molecule. In this study, the β-glucans (BG) from yeasts have been used to test their immunomodulatory activity and adjuvant effect on the properties of ST. This study aimed to synthesize and characterize a conjugate of yeast-derived β-glucan with the ST enterotoxin (BG-ST) and evaluate the antigenic and antioxidant activities in mouse splenocytes. Fourier transform infrared spectroscopy and scanning electron microscopy analysis showed new bands and changes in morphology, respectively, confirming ST was successfully coupled to beta glucan. Additionally, according to the enzyme-linked immunosorbent assay (ELISA), conjugation efficiency was almost 90%. Cellular viability, phagocytic cell proportion, and respiratory burst enhanced splenocytes stimulated by BG-ST. In addition, nitric oxide production and antioxidant enzymes increased in cells stimulated with BG-ST, BG and ST. In conclusion, the results revealed the successful conjugation of β-glucan with ST peptide enhancing immune and antioxidant parameters to a greater extent than their individual components.
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Affiliation(s)
- Veronica Sanchez
- Immunology & Vaccinology Group, Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Av. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico; Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª, Sección, 78210 San Luis Potosí, Mexico
| | - Sergio Rosales-Mendoza
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª, Sección, 78210 San Luis Potosí, Mexico
| | - Elizabeth Monreal-Escalante
- Immunology & Vaccinology Group, Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Av. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico; CONACYT-Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Instituto Politécnico Nacional 195, Playa Palo de Santa Rita Sur, La Paz, B.C.S 23090, Mexico
| | - Jesús I Murillo-Álvarez
- Centro Interdisciplinario de Ciencias Marinas-IPN (CICIMAR), Avenida IPN s/n, 23096 La Paz, B.C.S., Mexico
| | - Carlos Angulo
- Immunology & Vaccinology Group, Centro de Investigaciones Biológicas del Noroeste (CIBNOR), Av. Instituto Politécnico Nacional 195, Playa Palo de Santa Rita, La Paz, B.C.S. 23096, Mexico.
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23
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Abstract
Enteric viral and bacterial infections continue to be a leading cause of mortality and morbidity in young children in low-income and middle-income countries, the elderly, and immunocompromised individuals. Vaccines are considered an effective and practical preventive approach against the predominantly fecal-to-oral transmitted gastroenteritis particularly in the resource-limited countries or regions where implementation of sanitation systems and supply of safe drinking water are not quickly achievable. While vaccines are available for a few enteric pathogens including rotavirus and cholera, there are no vaccines licensed for many other enteric viral and bacterial pathogens. Challenges in enteric vaccine development include immunological heterogeneity among pathogen strains or isolates, a lack of animal challenge models to evaluate vaccine candidacy, undefined host immune correlates to protection, and a low protective efficacy among young children in endemic regions. In this article, we briefly updated the progress and challenges in vaccines and vaccine development for the leading enteric viral and bacterial pathogens including rotavirus, human calicivirus, Shigella, enterotoxigenic Escherichia coli (ETEC), cholera, nontyphoidal Salmonella, and Campylobacter, and introduced a novel epitope- and structure-based vaccinology platform known as MEFA (multiepitope fusion antigen) and the application of MEFA for developing broadly protective multivalent vaccines against heterogenous pathogens.
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Affiliation(s)
- Hyesuk Seo
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
| | - Qiangde Duan
- University of Yangzhou, Institute of Comparative Medicine, Yangzhou, PR China
| | - Weiping Zhang
- University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA,CONTACT Weiping Zhang, University of Illinois at Urbana-Champaign, Department of Pathobiology, Urbana, Illinois, USA
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24
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Riaz S, Steinsland H, Hanevik K. Human Mucosal IgA Immune Responses against Enterotoxigenic Escherichia coli. Pathogens 2020; 9:pathogens9090714. [PMID: 32872549 PMCID: PMC7558491 DOI: 10.3390/pathogens9090714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 08/11/2020] [Accepted: 08/24/2020] [Indexed: 12/14/2022] Open
Abstract
Infection with enterotoxigenic Escherichia coli (ETEC) is a major contributor to diarrheal illness in children in low- and middle-income countries and travelers to these areas. There is an ongoing effort to develop vaccines against ETEC, and the most reliable immune correlate of protection against ETEC is considered to be the small intestinal secretory IgA response that targets ETEC-specific virulence factors. Since isolating IgA from small intestinal mucosa is technically and ethically challenging, requiring the use of invasive medical procedures, several other indirect methods are used as a proxy for gauging the small intestinal IgA responses. In this review, we summarize the literature reporting on anti-ETEC human IgA responses observed in blood, activated lymphocyte assayss, intestinal lavage/duodenal aspirates, and saliva from human volunteers being experimentally infected with ETEC. We describe the IgA response kinetics and responder ratios against classical and noncanonical ETEC antigens in the different sample types and discuss the implications that the results may have on vaccine development and testing.
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Affiliation(s)
- Saman Riaz
- Department of Clinical Science, University of Bergen, Jonas Lies veg 87, N-5021 Bergen, Norway;
- Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, 5020 Bergen, Norway
| | - Hans Steinsland
- Centre for Intervention Science in Maternal and Child Health, Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, 5020 Bergen, Norway;
- Department of Biomedicine, University of Bergen, 5020 Bergen, Norway
| | - Kurt Hanevik
- Department of Clinical Science, University of Bergen, Jonas Lies veg 87, N-5021 Bergen, Norway;
- Norwegian National Advisory Unit on Tropical Infectious Diseases, Department of Medicine, Haukeland University Hospital, 5021 Bergen, Norway
- Correspondence: ; Tel.: +47-5597-5000; Fax: +47-5597-2950
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25
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Thibau A, Dichter AA, Vaca DJ, Linke D, Goldman A, Kempf VAJ. Immunogenicity of trimeric autotransporter adhesins and their potential as vaccine targets. Med Microbiol Immunol 2020; 209:243-263. [PMID: 31788746 PMCID: PMC7247748 DOI: 10.1007/s00430-019-00649-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 11/19/2019] [Indexed: 12/15/2022]
Abstract
The current problem of increasing antibiotic resistance and the resurgence of numerous infections indicate the need for novel vaccination strategies more than ever. In vaccine development, the search for and the selection of adequate vaccine antigens is the first important step. In recent years, bacterial outer membrane proteins have become of major interest, as they are the main proteins interacting with the extracellular environment. Trimeric autotransporter adhesins (TAAs) are important virulence factors in many Gram-negative bacteria, are localised on the bacterial surface, and mediate the first adherence to host cells in the course of infection. One example is the Neisseria adhesin A (NadA), which is currently used as a subunit in a licensed vaccine against Neisseria meningitidis. Other TAAs that seem promising vaccine candidates are the Acinetobacter trimeric autotransporter (Ata), the Haemophilus influenzae adhesin (Hia), and TAAs of the genus Bartonella. Here, we review the suitability of various TAAs as vaccine candidates.
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Affiliation(s)
- Arno Thibau
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Alexander A. Dichter
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Diana J. Vaca
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
| | - Dirk Linke
- Section for Genetics and Evolutionary Biology, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Adrian Goldman
- Astbury Centre for Structural Molecular Biology, School of Biomedical Sciences, University of Leeds, Leeds, UK
- Molecular and Integrative Biosciences Program, University of Helsinki, Helsinki, Finland
| | - Volkhard A. J. Kempf
- Institute for Medical Microbiology and Infection Control, University Hospital, Goethe-University, Paul-Ehrlich-Str. 40, 60596 Frankfurt am Main, Germany
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26
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Jumani RS, Spector JM, Izadnegahdar R, Kelly P, Diagana TT, Manjunatha UH. Innovations in Addressing Pediatric Diarrhea in Low Resource Settings. ACS Infect Dis 2020; 6:14-24. [PMID: 31612701 DOI: 10.1021/acsinfecdis.9b00315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Diarrhea has long been recognized as an important cause of mortality during childhood. In parallel with ensuring access to proven care practices is the imperative to apply modern advances in medicine, science, and technology to accelerate progress against diarrheal disease, particularly in developing countries where the burden of avoidable harm is the greatest. In order to highlight achievements and identify outstanding areas of need, we reviewed the landscape of recent innovations that have significance for the study and clinical management of pediatric diarrhea in low resource settings.
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Affiliation(s)
- Rajiv S. Jumani
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Jonathan M. Spector
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Rasa Izadnegahdar
- Bill and Melinda Gates Foundation, 440 5th Ave N, Seattle, Washington 98109, United States
| | - Paul Kelly
- Blizard Institute, Barts and The London School of Medicine, Queen Mary University of London, Turner Street, London E1 2AD, United Kingdom
- Tropical Gastroenterology and Nutrition group, University of Zambia School of Medicine, Nationalist Road, Lusaka, Zambia
| | - Thierry T. Diagana
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
| | - Ujjini H. Manjunatha
- Novartis Institute for Tropical Diseases, 5300 Chiron Way, Emeryville, California 94608, United States
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27
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Booster vaccination with a fractional dose of an oral cholera vaccine induces comparable vaccine-specific antibody avidity as a full dose: A randomised clinical trial. Vaccine 2020; 38:655-662. [DOI: 10.1016/j.vaccine.2019.10.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 10/16/2019] [Accepted: 10/17/2019] [Indexed: 01/06/2023]
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28
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Anderson JD, Bagamian KH, Muhib F, Baral R, Laytner LA, Amaya M, Wierzba T, Rheingans R. Potential impact and cost-effectiveness of future ETEC and Shigella vaccines in 79 low- and lower middle-income countries. Vaccine X 2019; 2:100024. [PMID: 31384741 PMCID: PMC6668229 DOI: 10.1016/j.jvacx.2019.100024] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2019] [Revised: 04/15/2019] [Accepted: 04/16/2019] [Indexed: 12/12/2022] Open
Abstract
While diarrhea mortality in children has declined over the last two decades, there has been a slower decline in diarrheal episodes. Repeated diarrheal episodes are associated with childhood stunting, which leads to increased mortality risk from infectious diseases. Vaccine candidates are under development for enterotoxigenic Escherichia coli [ETEC] and Shigella, important enteric pathogens in children in low income countries. These future vaccines could significantly reduce diarrheal burden, prevent ETEC- and Shigella-induced stunting, and stunting-associated mortality. We developed a cost-effectiveness model for two putative standalone ETEC and Shigella vaccine candidates to evaluate vaccine impact on mortality, morbidity, stunting, and stunting-associated deaths from other infectious diseases. We modeled impact over the first ten years after vaccine introduction in children under five years old living in 79 low and low-middle income countries. ETEC and Shigella diarrhea would cause an estimated 239,300 [95% UL: 179,700-309,800] and 340,300 [256,500-440,800] child deaths, respectively, from years 2025 to 2034. Most of these deaths would occur in AFRO countries. ETEC and Shigella moderate-to-severe diarrheal episodes would result in over 13.7 [8.4-19.0] and 21.4 [13.1-29.8] million stunted children, respectively. Introducing ETEC or Shigella vaccine each with 60% efficacy could prevent 92,000 [61,000-129,000] ETEC and 126,600 [84,000-179,000] Shigella direct deaths and 21,400 [11,300-34,800] ETEC- and 34,200 [18,000-56,000] Shigella-induced stunting deaths. ETEC ICERs ranged from $2172/DALY [1457-4369] in AFRO to $19,172/DALY [12,665-39,503] in EURO. Shigella ICERs ranged from $952/DALY [632-2001] in EMRO to $640,316/DALY [434,311-1,297,192] in EURO. Limitations of this analysis include uncertainty of vaccine efficacy, duration of protection, and vaccine price. Inclusion of other infectious disease mortality due to stunting provides a more accurate assessment of total ETEC and Shigella disease burden and increased the projected impact and cost-effectiveness of vaccination. Introducing vaccines only in high burden countries and regions could substantially reduce cost without substantially reducing impact.
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Affiliation(s)
- John D Anderson
- Goodnight Family Department of Sustainable Development, Appalachian State University, 222 Living Learning Center, 305 Bodenheimer Drive, Boone, NC 28608, USA
- Emerging Pathogens Institute, P.O. Box 100009, 2055 Mowry Road, Gainesville, FL 32610, USA
| | - Karoun H Bagamian
- Department of Environmental and Global Health, University of Florida, Gainesville, FL 32603, USA
- Bagamian Scientific Consulting, 978 SW 2Ave., Gainesville, FL 32601, USA
| | - Farzana Muhib
- PATH, 455 Massachusetts Ave. NW, Suite 1000, Washington, DC 20001, USA
| | - Ranju Baral
- PATH, 201 Westlake Avenue, Suite 200, Seattle, WA 98121, USA
| | - Lindsey A Laytner
- Emerging Pathogens Institute, P.O. Box 100009, 2055 Mowry Road, Gainesville, FL 32610, USA
- Department of Environmental and Global Health, University of Florida, Gainesville, FL 32603, USA
| | - Mirna Amaya
- Emerging Pathogens Institute, P.O. Box 100009, 2055 Mowry Road, Gainesville, FL 32610, USA
- Department of Environmental and Global Health, University of Florida, Gainesville, FL 32603, USA
| | - Thomas Wierzba
- PATH, 455 Massachusetts Ave. NW, Suite 1000, Washington, DC 20001, USA
| | - Richard Rheingans
- Goodnight Family Department of Sustainable Development, Appalachian State University, 222 Living Learning Center, 305 Bodenheimer Drive, Boone, NC 28608, USA
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29
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Vidal RM, Muhsen K, Tennant SM, Svennerholm AM, Sow SO, Sur D, Zaidi AKM, Faruque ASG, Saha D, Adegbola R, Hossain MJ, Alonso PL, Breiman RF, Bassat Q, Tamboura B, Sanogo D, Onwuchekwa U, Manna B, Ramamurthy T, Kanungo S, Ahmed S, Qureshi S, Quadri F, Hossain A, Das SK, Antonio M, Mandomando I, Nhampossa T, Acácio S, Omore R, Ochieng JB, Oundo JO, Mintz ED, O’Reilly CE, Berkeley LY, Livio S, Panchalingam S, Nasrin D, Farag TH, Wu Y, Sommerfelt H, Robins-Browne RM, Del Canto F, Hazen TH, Rasko DA, Kotloff KL, Nataro JP, Levine MM. Colonization factors among enterotoxigenic Escherichia coli isolates from children with moderate-to-severe diarrhea and from matched controls in the Global Enteric Multicenter Study (GEMS). PLoS Negl Trop Dis 2019; 13:e0007037. [PMID: 30608930 PMCID: PMC6343939 DOI: 10.1371/journal.pntd.0007037] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 01/23/2019] [Accepted: 11/28/2018] [Indexed: 12/29/2022] Open
Abstract
Background Enterotoxigenic Escherichia coli (ETEC) encoding heat-stable enterotoxin (ST) alone or with heat-labile enterotoxin (LT) cause moderate-to-severe diarrhea (MSD) in developing country children. The Global Enteric Multicenter Study (GEMS) identified ETEC encoding ST among the top four enteropathogens. Since the GEMS objective was to provide evidence to guide development and implementation of enteric vaccines and other interventions to diminish diarrheal disease morbidity and mortality, we examined colonization factor (CF) prevalence among ETEC isolates from children age <5 years with MSD and from matched controls in four African and three Asian sites. We also assessed strength of association of specific CFs with MSD. Methodology/Principal findings MSD cases enrolled at healthcare facilities over three years and matched controls were tested in a standardized manner for many enteropathogens. To identify ETEC, three E. coli colonies per child were tested by polymerase chain reaction (PCR) to detect genes encoding LT, ST; confirmed ETEC were examined by PCR for major CFs (Colonization Factor Antigen I [CFA/I] or Coli Surface [CS] antigens CS1-CS6) and minor CFs (CS7, CS12, CS13, CS14, CS17, CS18, CS19, CS20, CS21, CS30). ETEC from 806 cases had a single toxin/CF profile in three tested strains per child. Major CFs, components of multiple ETEC vaccine candidates, were detected in 66.0% of LT/ST and ST-only cases and were associated with MSD versus matched controls by conditional logistic regression (p≤0.006); major CFs detected in only 25.0% of LT-only cases weren’t associated with MSD. ETEC encoding exclusively CS14, identified among 19.9% of 291 ST-only and 1.5% of 259 LT/ST strains, were associated with MSD (p = 0.0011). No other minor CF exhibited prevalence ≥5% and significant association with MSD. Conclusions/Significance Major CF-based efficacious ETEC vaccines could potentially prevent up to 66% of pediatric MSD cases due to ST-encoding ETEC in developing countries; adding CS14 extends coverage to ~77%. Enterotoxigenic Escherichia coli (“ETEC”) were found to be one of the four most consistently important agents that cause moderate-to-severe diarrhea among children <5 years of age in a large case-control study, the Global Enteric Multicenter Study, performed in four countries in sub-Saharan Africa and three in South Asia. ETEC attach to the lining of the human small intestine by means of protein colonization factors (CFs), after which bacterial toxins stimulate intestinal secretion resulting in diarrhea. Moderate-to-severe diarrhea in young children in developing countries can lead to malnutrition and death. Vaccines are being developed to prevent ETEC diarrhea and its consequences. Several ETEC vaccines aim to stimulate antibodies (protective proteins) that will bind CFs and prevent the bacteria from attaching to intestinal cells, which should, in turn, prevent ETEC diarrhea. Different types of CFs exist. To guide the development of vaccines intending to provide broad protection against ETEC, one must know the frequency with which the different major CFs are produced by ETEC. This paper reports an extensive systematic survey of ETEC CFs and provides helpful information to guide the development of ETEC vaccines.
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Affiliation(s)
- Roberto M. Vidal
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Khitam Muhsen
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sharon M. Tennant
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology at Institute of Biomedicine, University of Göteborg, Göteborg, Sweden
| | - Samba O. Sow
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Dipika Sur
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Anita K. M. Zaidi
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Abu S. G. Faruque
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Debasish Saha
- Medical Research Council (United Kingdom) Unit, Fajara, The Gambia
| | - Richard Adegbola
- Medical Research Council (United Kingdom) Unit, Fajara, The Gambia
| | | | - Pedro L. Alonso
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- ISGlobal, Barcelona Ctr. Int. Health Res. Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | - Robert F. Breiman
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
- Global Disease Detection Division, Kenya Office of the US Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Quique Bassat
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
- ISGlobal, Barcelona Ctr. Int. Health Res. Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
| | - Boubou Tamboura
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Doh Sanogo
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Uma Onwuchekwa
- Centre pour le Développement des Vaccins du Mali (CVD-Mali), Bamako, Mali
| | - Byomkesh Manna
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | | | - Suman Kanungo
- National Institute of Cholera and Enteric Diseases, Kolkata, India
| | - Shahnawaz Ahmed
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Shahida Qureshi
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Farheen Quadri
- Department of Paediatrics and Child Health, the Aga Khan University, Karachi, Pakistan
| | - Anowar Hossain
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Sumon K. Das
- International Centre for Diarrhoeal Disease Research, Mohakhali, Dhaka, Bangladesh
| | - Martin Antonio
- Medical Research Council (United Kingdom) Unit, Fajara, The Gambia
| | | | | | - Sozinho Acácio
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
| | - Richard Omore
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - John B. Ochieng
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Joseph O. Oundo
- Kenya Medical Research Institute/Centers for Disease Control and Prevention, Kisumu, Kenya
| | - Eric D. Mintz
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Ciara E. O’Reilly
- Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America
| | - Lynette Y. Berkeley
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sofie Livio
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sandra Panchalingam
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Dilruba Nasrin
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Tamer H. Farag
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Yukun Wu
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Halvor Sommerfelt
- Centre of Intervention Science in Maternal and Child Health, Centre for International Health, Department of Global Public Health and Primary Care, University of Bergen, Bergen, Norway
- Norwegian Institute of Public Health, Oslo, Norway
| | - Roy M. Robins-Browne
- Department of Microbiology and Immunology, Peter Doherty Institute for Infection and Immunity, The University of Melbourne, Victoria, Australia
| | - Felipe Del Canto
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Tracy H. Hazen
- The Institute of Genomic Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - David A. Rasko
- The Institute of Genomic Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Karen L. Kotloff
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - James P. Nataro
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Myron M. Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD, United States of America
- * E-mail:
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30
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Akhtar M, Chowdhury MI, Bhuiyan TR, Kaim J, Ahmed T, Rafique TA, Khan A, Rahman SIA, Khanam F, Begum YA, Sharif MZ, Islam LN, Carlin N, Maier N, Fix A, Wierzba TF, Walker RI, Bourgeois AL, Svennerholm AM, Qadri F, Lundgren A. Evaluation of the safety and immunogenicity of the oral inactivated multivalent enterotoxigenic Escherichia coli vaccine ETVAX in Bangladeshi adults in a double-blind, randomized, placebo-controlled Phase I trial using electrochemiluminescence and ELISA assays for immunogenicity analyses. Vaccine 2018; 37:5645-5656. [PMID: 30473185 PMCID: PMC6717083 DOI: 10.1016/j.vaccine.2018.11.040] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/25/2018] [Accepted: 11/14/2018] [Indexed: 12/22/2022]
Abstract
The safety and immunogenicity of the second generation oral enterotoxigenic Escherichia coli (ETEC) vaccine ETVAX, consisting of inactivated recombinant E. coli strains over-expressing the colonization factors (CFs) CFA/I, CS3, CS5 and CS6 and the heat labile toxoid LCTBA, were evaluated in Bangladeshi volunteers. To enable analysis of antibody responses against multiple vaccine antigens for subsequent use in small sample volumes from children, a sensitive electrochemiluminescence (ECL) assay for analysis of intestine-derived antibody-secreting cell responses using the antibodies in lymphocyte secretions (ALS) assay was established using Meso Scale Discovery technology. Three groups of Bangladeshi adults (n = 15 per group) received two oral doses of ETVAX with or without double mutant LT (dmLT) adjuvant or placebo in the initial part of a randomized, double-blind, placebo-controlled, age-descending, dose-escalation trial. CF- and LTB-specific ALS and plasma IgA responses were analyzed by ECL and/or ELISA. ETVAX was safe and well tolerated in the adults. Magnitudes of IgA ALS responses determined by ECL and ELISA correlated well (r = 0.85 to 0.98 for the five primary antigens, P < 0.001) and ECL was selected as the ALS readout method. ALS IgA responses against each of the primary antigens were detected in 87-100% of vaccinees after the first and in 100% after the second vaccine dose. Plasma IgA responses against different CFs and LTB were observed in 62-93% and 100% of vaccinees, respectively. No statistically significant adjuvant effect of dmLT on antibody responses to any antigen was detected, but the overall antigenic breadth of the plasma IgA response tended to favor the adjuvanted vaccine when responses to 4 or more or 5 vaccine antigens were considered. Responses in placebo recipients were infrequent and mainly detected against single antigens. The promising results in adults supported testing ETVAX in descending age groups of children. ClinicalTrials.gov Identifier: NCT02531802.
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Affiliation(s)
- Marjahan Akhtar
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Mohiul I Chowdhury
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Taufiqur R Bhuiyan
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Joanna Kaim
- GUVAX (Gothenburg University Vaccine Research Institute), Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden
| | - Tasnuva Ahmed
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Tanzeem A Rafique
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Arifuzzaman Khan
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Sadia I A Rahman
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Farhana Khanam
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Yasmin A Begum
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Mir Z Sharif
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Laila N Islam
- Dept. of Biochemistry and Molecular Biology, University of Dhaka, Bangladesh
| | | | | | | | | | | | | | - Ann-Mari Svennerholm
- GUVAX (Gothenburg University Vaccine Research Institute), Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden
| | - Firdausi Qadri
- icddr,b (International Centre for Diarrhoeal Disease Research, Bangladesh), Dhaka, Bangladesh
| | - Anna Lundgren
- GUVAX (Gothenburg University Vaccine Research Institute), Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden.
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31
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Riddle M, Chen W, Kirkwood C, MacLennan C. Update on vaccines for enteric pathogens. Clin Microbiol Infect 2018; 24:1039-1045. [DOI: 10.1016/j.cmi.2018.06.023] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 06/17/2018] [Accepted: 06/19/2018] [Indexed: 12/12/2022]
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32
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Carvalho MF, Gill D. Rotavirus vaccine efficacy: current status and areas for improvement. Hum Vaccin Immunother 2018; 15:1237-1250. [PMID: 30215578 PMCID: PMC6663136 DOI: 10.1080/21645515.2018.1520583] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/12/2018] [Accepted: 08/28/2018] [Indexed: 12/16/2022] Open
Abstract
The difference noted in Rotavirus vaccine efficiency between high and low income countries correlates with the lack of universal access to clean water and higher standards of hygiene. Overcoming these obstacles will require great investment and also time, therefore more effective vaccines should be developed to meet the needs of those who would benefit the most from them. Increasing our current knowledge of mucosal immunity, response to Rotavirus infection and its modulation by circadian rhythms could point at actionable pathways to improve vaccination efficacy, especially in the case of individuals affected by environmental enteropathy. Also, a better understanding and validation of Rotavirus entry factors as well as the systematic monitoring of dominant strains could assist in tailoring vaccines to individual's needs. Another aspect that could improve vaccine efficiency is targeting to M cells, for which new ligands could potentially be sought. Finally, alternative mucosal adjuvants and vaccine expression, storage and delivery systems could have a positive impact in the outcome of Rotavirus vaccination.
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Affiliation(s)
| | - Davinder Gill
- MSD Wellcome Trust Hilleman Laboratories Pvt. Ltd., New Delhi, India
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33
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Zegeye ED, Govasli ML, Sommerfelt H, Puntervoll P. Development of an enterotoxigenic Escherichia coli vaccine based on the heat-stable toxin. Hum Vaccin Immunother 2018; 15:1379-1388. [PMID: 30081709 PMCID: PMC6663125 DOI: 10.1080/21645515.2018.1496768] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Infection with enterotoxigenic Escherichia coli (ETEC) is an important cause of diarrhea-related illness and death among children under 5 years of age in low– and middle-income countries (LMIC). Recent studies have found that it is the ETEC subtypes that produce the heat-stable enterotoxin (ST), irrespective of whether they also secrete the heat-labile enterotoxin (LT), which contribute most importantly to the disease burden in children from LMIC. Therefore, adding an ST toxoid would importantly complement ongoing ETEC vaccine development efforts. The ST’s potent toxicity, its structural similarity to the endogenous peptides guanylin and uroguanylin, and its poor immunogenicity have all complicated the advancement of ST-based vaccine development. Recent remarkable progress, however, including the unprecedented screening for optimal ST mutants, mapping of cross-reacting ST epitopes and improved ST-carrier coupling strategies (bioconjugation and genetic fusion), enables the rational design of safe, immunogenic, and well-defined ST-based vaccine candidates.
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Affiliation(s)
| | | | - Halvor Sommerfelt
- b Centre for Intervention Science in Maternal and Child Health, Centre for International Health, Department of Global Public Health and Primary Care , University of Bergen , Bergen , Norway.,c Norwegian Institute of Public Health , Oslo , Norway
| | - Pål Puntervoll
- a Centre for Applied Biotechnology , Uni Research AS , Bergen , Norway
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