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Lamichhane B, Mawad AMM, Saleh M, Kelley WG, Harrington PJ, Lovestad CW, Amezcua J, Sarhan MM, El Zowalaty ME, Ramadan H, Morgan M, Helmy YA. Salmonellosis: An Overview of Epidemiology, Pathogenesis, and Innovative Approaches to Mitigate the Antimicrobial Resistant Infections. Antibiotics (Basel) 2024; 13:76. [PMID: 38247636 PMCID: PMC10812683 DOI: 10.3390/antibiotics13010076] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 12/24/2023] [Accepted: 01/10/2024] [Indexed: 01/23/2024] Open
Abstract
Salmonella is a major foodborne pathogen and a leading cause of gastroenteritis in humans and animals. Salmonella is highly pathogenic and encompasses more than 2600 characterized serovars. The transmission of Salmonella to humans occurs through the farm-to-fork continuum and is commonly linked to the consumption of animal-derived food products. Among these sources, poultry and poultry products are primary contributors, followed by beef, pork, fish, and non-animal-derived food such as fruits and vegetables. While antibiotics constitute the primary treatment for salmonellosis, the emergence of antibiotic resistance and the rise of multidrug-resistant (MDR) Salmonella strains have highlighted the urgency of developing antibiotic alternatives. Effective infection management necessitates a comprehensive understanding of the pathogen's epidemiology and transmission dynamics. Therefore, this comprehensive review focuses on the epidemiology, sources of infection, risk factors, transmission dynamics, and the host range of Salmonella serotypes. This review also investigates the disease characteristics observed in both humans and animals, antibiotic resistance, pathogenesis, and potential strategies for treatment and control of salmonellosis, emphasizing the most recent antibiotic-alternative approaches for infection control.
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Affiliation(s)
- Bibek Lamichhane
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Asmaa M. M. Mawad
- Botany and Microbiology Department, Faculty of Science, Assiut University, Assiut 71516, Egypt
| | - Mohamed Saleh
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - William G. Kelley
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Patrick J. Harrington
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Cayenne W. Lovestad
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Jessica Amezcua
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Mohamed M. Sarhan
- Faculty of Pharmacy, King Salman International University (KSIU), Ras Sudr 8744304, Egypt
| | - Mohamed E. El Zowalaty
- Veterinary Medicine and Food Security Research Group, Medical Laboratory Sciences Program, Faculty of Health Sciences, Abu Dhabi Women’s Campus, Higher Colleges of Technology, Abu Dhabi 41012, United Arab Emirates
| | - Hazem Ramadan
- Hygiene and Zoonoses Department, Faculty of Veterinary Medicine, Mansoura University, Mansoura 35516, Egypt
| | - Melissa Morgan
- Department of Animal and Food Sciences, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
| | - Yosra A. Helmy
- Department of Veterinary Science, Martin-Gatton College of Agriculture, Food and Environment, University of Kentucky, Lexington, KY 40546, USA
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Jossi SE, Arcuri M, Alshayea A, Persaud RR, Marcial-Juárez E, Palmieri E, Di Benedetto R, Pérez-Toledo M, Pillaye J, Channell WM, Schager AE, Lamerton RE, Cook CN, Goodall M, Haneda T, Bäumler AJ, Jackson-Jones LH, Toellner KM, MacLennan CA, Henderson IR, Micoli F, Cunningham AF. Vi polysaccharide and conjugated vaccines afford similar early, IgM or IgG-independent control of infection but boosting with conjugated Vi vaccines sustains the efficacy of immune responses. Front Immunol 2023; 14:1139329. [PMID: 37033932 PMCID: PMC10076549 DOI: 10.3389/fimmu.2023.1139329] [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: 01/06/2023] [Accepted: 03/13/2023] [Indexed: 04/11/2023] Open
Abstract
Introduction Vaccination with Vi capsular polysaccharide (Vi-PS) or protein-Vi typhoid conjugate vaccine (TCV) can protect adults against Salmonella Typhi infections. TCVs offer better protection than Vi-PS in infants and may offer better protection in adults. Potential reasons for why TCV may be superior in adults are not fully understood. Methods and results Here, we immunized wild-type (WT) mice and mice deficient in IgG or IgM with Vi-PS or TCVs (Vi conjugated to tetanus toxoid or CRM197) for up to seven months, with and without subsequent challenge with Vi-expressing Salmonella Typhimurium. Unexpectedly, IgM or IgG alone were similarly able to reduce bacterial burdens in tissues, and this was observed in response to conjugated or unconjugated Vi vaccines and was independent of antibody being of high affinity. Only in the longer-term after immunization (>5 months) were differences observed in tissue bacterial burdens of mice immunized with Vi-PS or TCV. These differences related to the maintenance of antibody responses at higher levels in mice boosted with TCV, with the rate of fall in IgG titres induced to Vi-PS being greater than for TCV. Discussion Therefore, Vi-specific IgM or IgG are independently capable of protecting from infection and any superior protection from vaccination with TCV in adults may relate to responses being able to persist better rather than from differences in the antibody isotypes induced. These findings suggest that enhancing our understanding of how responses to vaccines are maintained may inform on how to maximize protection afforded by conjugate vaccines against encapsulated pathogens such as S. Typhi.
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Affiliation(s)
- Siân E. Jossi
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Melissa Arcuri
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
- GSK Vaccines Institute for Global Health SRL, Siena, Italy
| | - Areej Alshayea
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Ruby R. Persaud
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Edith Marcial-Juárez
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Elena Palmieri
- GSK Vaccines Institute for Global Health SRL, Siena, Italy
| | | | - Marisol Pérez-Toledo
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Jamie Pillaye
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Will M. Channell
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Anna E. Schager
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Rachel E. Lamerton
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Charlotte N. Cook
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Margaret Goodall
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Takeshi Haneda
- Laboratory of Microbiology, School of Pharmacy, Kitasato University, Tokyo, Japan
| | - Andreas J. Bäumler
- Department of Medical Microbiology and Immunology, School of Medicine, University of California, Davis, CA, United States
| | - Lucy H. Jackson-Jones
- Division of Biomedical and Life Sciences, Lancaster University, Lancaster, United Kingdom
| | - Kai-Michael Toellner
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
| | - Calman A. MacLennan
- Bill & Melinda Gates Foundation, London, United Kingdom
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Ian R. Henderson
- Institute for Molecular Bioscience, University of Queensland, Brisbane, QLD, Australia
| | | | - Adam F. Cunningham
- Institute of Immunology and Immunotherapy, University of Birmingham, Birmingham, United Kingdom
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Liston SD, Ovchinnikova OG, Kimber MS, Whitfield C. A dedicated C-6 β-hydroxyacyltransferase required for biosynthesis of the glycolipid anchor for Vi antigen capsule in typhoidal Salmonella. J Biol Chem 2022; 298:102520. [PMID: 36152747 DOI: 10.1016/j.jbc.2022.102520] [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: 08/02/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 11/17/2022] Open
Abstract
Vi antigen is an extracellular polysaccharide produced by Salmonella enterica Typhi, Citrobacter freundii, and some soil bacteria belonging to the Burkholderiales. In Salmonella Typhi, Vi-antigen capsule protects the bacterium against host defenses, and the glycan is used in a current glycoconjugate vaccine to protect against typhoid. Vi antigen is a glycolipid assembled in the cytoplasm and translocated to the cell surface by an export complex driven by an ABC transporter. In Salmonella Typhi, efficient export and cell-surface retention of the capsule layer depend on a reducing terminal acylated-HexNAc moiety. Although the precise structure and biosynthesis of the acylated terminus has not been resolved, it distinguishes Vi antigen from other known glycolipid substrates for bacterial ABC transporters. The genetic locus for Vi antigen-biosynthesis encodes a single acyltransferase candidate (VexE), which is implicated in the acylation process. Here, we determined the structure of the VexE in vitro reaction product by mass spectrometry and nuclear magnetic resonance spectroscopy, to reveal that VexE catalyzes β-hydroxyacyl-ACP dependent acylation of the activated sugar precursor, uridine-5'-diphospho-N-acetylglucosamine (UDP-GlcNAc), at C-6 to form UDP-6-O-[β-hydroxymyristoyl]-α-d-GlcNAc. VexE belongs to the lysophosphatidyl acyltransferase (LPLAT) family, and comparison of an Alphafold VexE model to solved LPLAT structures, together with modeling enzyme:substrate complexes, led us to predict an enzyme mechanism. This study provides new insight into Vi terminal structure, offers a new model substrate to investigate the mechanism of glycolipid ABC transporters, and adds biochemical understanding for a novel reaction used in synthesis of an important bacterial virulence factor.
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Affiliation(s)
- S D Liston
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - O G Ovchinnikova
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - M S Kimber
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - C Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.
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Micoli F, Alfini R, Di Benedetto R, Necchi F, Schiavo F, Mancini F, Carducci M, Oldrini D, Pitirollo O, Gasperini G, Balocchi C, Bechi N, Brunelli B, Piccioli D, Adamo R. Generalized Modules for Membrane Antigens as Carrier for Polysaccharides: Impact of Sugar Length, Density, and Attachment Site on the Immune Response Elicited in Animal Models. Front Immunol 2021; 12:719315. [PMID: 34594333 PMCID: PMC8477636 DOI: 10.3389/fimmu.2021.719315] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/16/2021] [Indexed: 11/13/2022] Open
Abstract
Nanoparticle systems are being explored for the display of carbohydrate antigens, characterized by multimeric presentation of glycan epitopes and special chemico-physical properties of nano-sized particles. Among them, outer membrane vesicles (OMVs) are receiving great attention, combining antigen presentation with the immunopotentiator effect of the Toll-like receptor agonists naturally present on these systems. In this context, we are testing Generalized Modules for Membrane Antigens (GMMA), OMVs naturally released from Gram-negative bacteria mutated to increase blebbing, as carrier for polysaccharides. Here, we investigated the impact of saccharide length, density, and attachment site on the immune response elicited by GMMA in animal models, using a variety of structurally diverse polysaccharides from different pathogens (i.e., Neisseria meningitidis serogroup A and C, Haemophilus influenzae type b, and streptococcus Group A Carbohydrate and Salmonella Typhi Vi). Anti-polysaccharide immune response was not affected by the number of saccharides per GMMA particle. However, lower saccharide loading can better preserve the immunogenicity of GMMA as antigen. In contrast, saccharide length needs to be optimized for each specific antigen. Interestingly, GMMA conjugates induced strong functional immune response even when the polysaccharides were linked to sugars on GMMA. We also verified that GMMA conjugates elicit a T-dependent humoral immune response to polysaccharides that is strictly dependent on the nature of the polysaccharide. The results obtained are important to design novel glycoconjugate vaccines using GMMA as carrier and support the development of multicomponent glycoconjugate vaccines where GMMA can play the dual role of carrier and antigen. In addition, this work provides significant insights into the mechanism of action of glycoconjugates.
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Affiliation(s)
| | - Renzo Alfini
- GSK Vaccines Institute for Global Health (GVGH), Siena, Italy
| | | | | | - Fabiola Schiavo
- GSK Vaccines Institute for Global Health (GVGH), Siena, Italy
| | | | | | - Davide Oldrini
- GSK Vaccines Institute for Global Health (GVGH), Siena, Italy
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Shakya M, Neuzil KM, Pollard AJ. Prospects of future typhoid and paratyphoid vaccines in endemic countries. J Infect Dis 2021; 224:S770-S774. [PMID: 34374785 PMCID: PMC8687069 DOI: 10.1093/infdis/jiab393] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Low- and middle-income countries face a high burden of typhoid and paratyphoid fever due to poor water quality and inadequate sanitation. The World Health Organization (WHO) recommends the use of typhoid conjugate vaccines (TCV) in endemic settings and Gavi, the Vaccine Alliance, supports TCV introduction. There are currently two WHO-prequalified TCVs with Typbar TCV® introduced in Pakistan, Liberia, and Zimbabwe. Countries should assess disease burden and consider introduction of TCV for programmatic use. Several paratyphoid vaccine candidates are in early stages of development. An effective bivalent vaccine would be the most efficient way to control typhoid and paratyphoid fever.
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Affiliation(s)
- Mila Shakya
- Oxford University Clinical Research Unit - Nepal, Patan Academy of Health Sciences, Lalitpur, Nepal
| | - Kathleen M Neuzil
- University of Maryland School of Medicine, Baltimore, MD, United States
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, and the NIHR Oxford Biomedical Research Centre, Oxford, United Kingdom
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Zhao J, Hu G, Huang Y, Huang Y, Wei X, Shi J. Polysaccharide conjugate vaccine: A kind of vaccine with great development potential. CHINESE CHEM LETT 2021. [DOI: 10.1016/j.cclet.2020.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Salmonella Paratyphi A Outer Membrane Vesicles Displaying Vi Polysaccharide as a Multivalent Vaccine against Enteric Fever. Infect Immun 2021; 89:IAI.00699-20. [PMID: 33318138 DOI: 10.1128/iai.00699-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 12/07/2020] [Indexed: 12/23/2022] Open
Abstract
Typhoid and paratyphoid fevers have a high incidence worldwide and coexist in many geographical areas, especially in low-middle-income countries (LMIC) in South and Southeast Asia. There is extensive consensus on the urgent need for better and affordable vaccines against systemic Salmonella infections. Generalized modules for membrane antigens (GMMA), outer membrane exosomes shed by Salmonella bacteria genetically manipulated to increase blebbing, resemble the bacterial surface where protective antigens are displayed in their native environment. Here, we engineered S Paratyphi A using the pDC5-viaB plasmid to generate GMMA displaying the heterologous S Typhi Vi antigen together with the homologous O:2 O antigen. The presence of both Vi and O:2 was confirmed by flow cytometry on bacterial cells, and their amount was quantified on the resulting vesicles through a panel of analytical methods. When tested in mice, such GMMA induced a strong antibody response against both Vi and O:2, and these antibodies were functional in a serum bactericidal assay. Our approach yielded a bivalent vaccine candidate able to induce immune responses against different Salmonella serovars, which could benefit LMIC residents and travelers.
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GMMA Is a Versatile Platform to Design Effective Multivalent Combination Vaccines. Vaccines (Basel) 2020; 8:vaccines8030540. [PMID: 32957610 PMCID: PMC7564227 DOI: 10.3390/vaccines8030540] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 09/12/2020] [Accepted: 09/14/2020] [Indexed: 01/21/2023] Open
Abstract
Technology platforms are an important strategy to facilitate the design, development and implementation of vaccines to combat high-burden diseases that are still a threat for human populations, especially in low- and middle-income countries, and to address the increasing number and global distribution of pathogens resistant to antimicrobial drugs. Generalized Modules for Membrane Antigens (GMMA), outer membrane vesicles derived from engineered Gram-negative bacteria, represent an attractive technology to design affordable vaccines. Here, we show that GMMA, decorated with heterologous polysaccharide or protein antigens, leads to a strong and effective antigen-specific humoral immune response in mice. Importantly, GMMA promote enhanced immunogenicity compared to traditional formulations (e.g., recombinant proteins and glycoconjugate vaccines), without negative impact to the anti-GMMA immune response. Our findings support the use of GMMA as a “plug and play” technology for the development of effective combination vaccines targeting different bugs at the same time.
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Short Vi-polysaccharide abrogates T-independent immune response and hyporesponsiveness elicited by long Vi-CRM 197 conjugate vaccine. Proc Natl Acad Sci U S A 2020; 117:24443-24449. [PMID: 32900928 PMCID: PMC7533886 DOI: 10.1073/pnas.2005857117] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Our results suggest a rational way of designing and developing an improved typhoid conjugate vaccine and, by extension, to conjugate vaccines in general: first, modify a T-independent polysaccharide so that it no longer induces a T-independent response, then conjugate the polysaccharide to a suitable carrier protein restoring immunogenicity, thus creating a pure T-dependent antigen that induces a strongly boostable and long-lived response at an early age. Polysaccharide-protein conjugates have been developed to overcome the T-independent response, hyporesponsiveness to repeated vaccination, and poor immunogenicity in infants of polysaccharides. To address the impact of polysaccharide length, typhoid conjugates made with short- and long-chain fractions of Vi polysaccharide with average sizes of 9.5, 22.8, 42.7, 82.0, and 165 kDa were compared. Long-chain-conjugated Vi (165 kDa) induced a response in both wild-type and T cell-deficient mice, suggesting that it maintains a T-independent response. In marked contrast, short-chain Vi (9.5 to 42.7 kDa) conjugates induced a response in wild-type mice but not in T cell-deficient mice, suggesting that the response is dependent on T cell help. Mechanistically, this was explained in neonatal mice, in which long-chain, but not short-chain, Vi conjugate induced late apoptosis of Vi-specific B cells in spleen and early depletion of Vi-specific B cells in bone marrow, resulting in hyporesponsiveness and lack of long-term persistence of Vi-specific IgG in serum and IgG+ antibody-secreting cells in bone marrow. We conclude that while conjugation of long-chain Vi generates T-dependent antigens, the conjugates also retain T-independent properties, leading to detrimental effects on immune responses. The data reported here may explain some inconsistencies observed in clinical trials and help guide the design of effective conjugate vaccines.
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Meena J, Kumar R, Singh M, Ahmed A, Panda AK. Modulation of immune response and enhanced clearance of Salmonella typhi by delivery of Vi polysaccharide conjugate using PLA nanoparticles. Eur J Pharm Biopharm 2020; 152:270-281. [DOI: 10.1016/j.ejpb.2020.05.023] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/17/2020] [Accepted: 05/24/2020] [Indexed: 10/24/2022]
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Giannelli C, Raso MM, Palmieri E, De Felice A, Pippi F, Micoli F. Development of a Specific and Sensitive HPAEC-PAD Method for Quantification of Vi Polysaccharide Applicable to other Polysaccharides Containing Amino Uronic Acids. Anal Chem 2020; 92:6304-6311. [PMID: 32330386 DOI: 10.1021/acs.analchem.9b05107] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Typhoid fever is a major cause of morbidity and mortality in developing countries. Vaccines based on the Vi capsular polysaccharide are licensed or in development against typhoid fever. Vi content is a critical quality attribute for vaccines release, to monitor their stability and to ensure appropriate immune response. Vi polysaccharide is a homopolymer of α-1,4-N-acetylgalactosaminouronic acid, O-acetylated at the C-3 position, resistant to the commonly used acid hydrolysis for sugar chain depolymerization before monomer quantification. We previously developed a quantification method based on strong alkaline hydrolysis followed by High Performance Anion Exchange Chromatography-Pulsed Amperometric Detection analysis, but with low sensitivity and use for quantification of an unknown product coming from polysaccharide depolymerization. Here we describe the development of a method for Vi polysaccharide quantification based on acid hydrolysis with concomitant use of trifluoroacetic and hydrochloric acids. A Design of Experiment approach was used for the identification of the optimal hydrolysis conditions. The method is 100-fold more sensitive than the previous one, and specifically, resulting in the formation of a known product, confirmed to be the Vi monomer both de-O- and de-N-acetylated by mono- and bidimensional Nuclear Magnetic Resonance spectroscopy and mass spectrometry. Accuracy and precision were determined, and chromatographic conditions were improved to result in reduced time of analysis. This method will facilitate characterization of Vi-based vaccines. Furthermore, a similar approach has the potential to be extended to other polysaccharides containing 2-amino uronic acids, as already verified here for Shigella sonnei O-antigen, Streptococcus pneumoniae serotype 12F, and Staphylococcus aureus types 5 and 8 capsular polysaccharides.
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Affiliation(s)
- Carlo Giannelli
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100 Siena, Italy
| | | | - Elena Palmieri
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100 Siena, Italy
| | - Antonia De Felice
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100 Siena, Italy
| | - Federico Pippi
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100 Siena, Italy
| | - Francesca Micoli
- GSK Vaccines Institute for Global Health, Via Fiorentina 1, 53100 Siena, Italy
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Jones C, An SJ, Yoon YK, Kothari S, Sahastrabuddhe S, Carbis R. Spectroscopic characterisation of a series of Salmonella Typhi Vi-diphtheria toxoid glycoconjugate antigens differing in polysaccharide-protein ratio. J Pharm Biomed Anal 2020; 181:113100. [PMID: 31991319 DOI: 10.1016/j.jpba.2020.113100] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 12/28/2019] [Accepted: 01/06/2020] [Indexed: 11/28/2022]
Abstract
Glycoconjugate vaccines consisting of the Salmonella enterica subsp. enterica serovar Typhi (S. Typhi) Vi capsular polysaccharide (PS) covalently attached to a suitable carrier protein have become available to support mass paediatric vaccination campaigns against typhoid. One developmental vaccine from the International Vaccine Institute (IVI) uses diphtheria toxoid (DTx) as the carrier protein. Several investigational conjugates with different PS:protein ratios were prepared, as previously reported by the IVI group, for physicochemical and immunochemical characterisation. We describe here the further spectroscopic characterisation of this series of glycoconjugate immunogen bulks using NMR spectroscopy, circular dichroism and absorption spectroscopy. We have used several mathematical approaches to extract information from the spectroscopic data not previously applied to glycoconjugates. These complementary approaches provide information on (i) the integrity of the carrier protein, (ii) consistency between batches of vaccine components, (iii) the polysaccharide: protein ratio (iv) the O-acetylation of the Vi in the conjugate (v) the stability of the O-acetylation of the Vi, and (vi) the presence of residual process reagents in the bulk. The utility of the data analysis approaches is discussed. Together, these analytical methods provide important characterisation of Vi-DTx conjugates to support development and quality control of commercial products.
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Affiliation(s)
- Christopher Jones
- Laboratory for Molecular Structure, National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Herts EN6 3QG, UK.
| | - So Jung An
- International Vaccine Institute, SNU Research Park, San 4-8, Nakseongdae-dong, Gwanak-gu 151-919, Seoul, Republic of Korea.
| | - Yeon Kyung Yoon
- International Vaccine Institute, SNU Research Park, San 4-8, Nakseongdae-dong, Gwanak-gu 151-919, Seoul, Republic of Korea.
| | - Sudeep Kothari
- International Vaccine Institute, SNU Research Park, San 4-8, Nakseongdae-dong, Gwanak-gu 151-919, Seoul, Republic of Korea.
| | - Sushant Sahastrabuddhe
- International Vaccine Institute, SNU Research Park, San 4-8, Nakseongdae-dong, Gwanak-gu 151-919, Seoul, Republic of Korea.
| | - Rodney Carbis
- International Vaccine Institute, SNU Research Park, San 4-8, Nakseongdae-dong, Gwanak-gu 151-919, Seoul, Republic of Korea.
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Voysey M, Pollard AJ. Seroefficacy of Vi Polysaccharide-Tetanus Toxoid Typhoid Conjugate Vaccine (Typbar TCV). Clin Infect Dis 2019; 67:18-24. [PMID: 29351594 DOI: 10.1093/cid/cix1145] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 01/04/2018] [Indexed: 11/14/2022] Open
Abstract
Background Salmonella Typhi is the major cause of enteric fever in lower-income countries. New conjugate vaccines show promise as public health interventions, but there are no efficacy data available from endemic areas. Methods Data were obtained from a previously published phase 3 randomized controlled trial comparing Vi polysaccharide-tetanus toxoid conjugate vaccine (Vi-TT) with Vi polysaccharide vaccine (Vi-PS) in participants aged 2-45 years. An additional open-label arm administered Vi-TT to children aged 6-23 months. The proportion of participants with presumed clinical or subclinical infection ("seroincidence") was determined using mixture models and compared using relative risks (RRs). Results Of 387 participants, 81 (21%) were classified as having presumed typhoid infection during the 2-year postvaccination period. Seroincidence was lower in participants randomized to Vi-TT rather than Vi-PS among those aged 2-45 years (RR, 0.372; 95% confidence interval [CI], .235-.588; P < .001) and those aged 2-15 years (RR, 0.424; 95% CI, .231-.778; P = .004). There was no difference in seroincidence for Vi-TT between those aged 2-45 years and those aged 6-23 months (RR, 1.073; 95% CI, .563-2.046; P = .83). Vaccine seroefficacy was 85% (95% CI, 80%-88%). Conclusion This is the first field estimate of the seroefficacy of a Vi-TT vaccine and shows that Typbar TCV substantially reduces the number of serologically defined clinical or subclinical infections in infants, children, and adults. These results support the recent World Health Organization recommendations for deployment of typhoid conjugate vaccines in high-burden areas.
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Affiliation(s)
- Merryn Voysey
- Nuffield Department of Primary Care Health Sciences, University of Oxford, United Kingdom.,Oxford Vaccine Group, Department of Paediatrics, University of Oxford, United Kingdom
| | - Andrew J Pollard
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, United Kingdom.,NIHR Oxford Biomedical Research Centre, United Kingdom
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Zhang GL, Wei MM, Song C, Ma YF, Zheng XJ, Xiong DC, Ye XS. Chemical synthesis and biological evaluation of penta- to octa- saccharide fragments of Vi polysaccharide fromSalmonella typhi. Org Chem Front 2018. [DOI: 10.1039/c8qo00471d] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The penta- to octa-saccharide fragments of Vi polysaccharide were synthesized efficiently, and the hexasaccharide might be the minimum epitope of Vi antigen based on ELISA analysis.
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Affiliation(s)
- Gao-Lan Zhang
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing 100191
- China
| | - Meng-Man Wei
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing 100191
- China
| | - Chengcheng Song
- School of Life Sciences
- Northeast Normal University
- Changchun 130024
- China
| | - Yu-Feng Ma
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing 100191
- China
| | - Xiu-Jing Zheng
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing 100191
- China
| | - De-Cai Xiong
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing 100191
- China
| | - Xin-Shan Ye
- State Key Laboratory of Natural and Biomimetic Drugs
- School of Pharmaceutical Sciences
- Peking University
- Beijing 100191
- China
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15
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Arcuri M, Di Benedetto R, Cunningham AF, Saul A, MacLennan CA, Micoli F. The influence of conjugation variables on the design and immunogenicity of a glycoconjugate vaccine against Salmonella Typhi. PLoS One 2017; 12:e0189100. [PMID: 29287062 PMCID: PMC5747453 DOI: 10.1371/journal.pone.0189100] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Accepted: 11/18/2017] [Indexed: 12/03/2022] Open
Abstract
In recent years there have been major efforts to develop glycoconjugate vaccines based on the Vi polysaccharide that will protect against Salmonella enterica Typhi infections, particularly typhoid fever, which remains a major public health concern in low-income countries. The design of glycoconjugate vaccines influences the immune responses they elicit. Here we systematically test the response in mice to Vi glycoconjugates that differ in Vi chain length (full-length and fragmented), carrier protein, conjugation chemistry, saccharide to protein ratio and size. We show that the length of Vi chains, but not the ultimate size of the conjugate, has an impact on the anti-Vi IgG immune response induced. Full-length Vi conjugates, independent of the carrier protein, induce peak IgG responses rapidly after just one immunization, and secondary immunization does not enhance the magnitude of these responses. Fragmented Vi linked to CRM197 and diphtheria toxoid, but not to tetanus toxoid, gives lower anti-Vi antibody responses after the first immunization than full-length Vi conjugates, but antibody titres are similar to those induced by full-length Vi conjugates following a second dose. The chemistry to conjugate Vi to the carrier protein, the linker used, and the saccharide to protein ratio do not significantly alter the response. We conclude that Vi length and carrier protein are the variables that influence the anti-Vi IgG response to immunization the most, while other parameters are of lesser importance.
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Affiliation(s)
- M. Arcuri
- GSK Vaccines Institute for Global Health (GVGH), Siena, Italy
- University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - R. Di Benedetto
- GSK Vaccines Institute for Global Health (GVGH), Siena, Italy
| | | | - A. Saul
- GSK Vaccines Institute for Global Health (GVGH), Siena, Italy
| | - C. A. MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - F. Micoli
- GSK Vaccines Institute for Global Health (GVGH), Siena, Italy
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16
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Salman M, St Michael F, Ali A, Jabbar A, Cairns C, Hayes AC, Rahman M, Iqbal M, Haque A, Cox AD. First characterization of immunogenic conjugates of Vi negative Salmonella Typhi O-specific polysaccharides with rEPA protein for vaccine development. J Immunol Methods 2017; 450:27-33. [PMID: 28735760 DOI: 10.1016/j.jim.2017.07.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2017] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 10/19/2022]
Abstract
Efficacious typhoid vaccines for young children will significantly reduce the disease burden in developing world. The Vi polysaccharide based conjugate vaccines (Vi-rEPA) against Salmonella Typhi Vi positive strains has shown high efficacy but may be ineffective against Vi negative S. Typhi. In this study, for the first time, we report the synthesis and evaluation of polysaccharide-protein conjugates of Vi negative S. Typhi as potential vaccine candidates. Four different conjugates were synthesized using recombinant exoprotein A of Pseudomonas aeruginosa (rEPA) and human serum albumin (HSA) as the carrier proteins, using either direct reductive amination or an intermediate linker molecule, adipic acid dihydrazide (ADH). Upon injection into mice, a significantly higher antibody titer was observed in mice administrated with conjugate-1 (OSP-HSA) (P=0.0001) and conjugate 2 (OSP-rEPA) (P≤0.0001) as compared to OSP alone. In contrast, the antibody titer elicited by conjugate 3 (OSPADH-HSA) and conjugate 4 (OSPADH-rEPA) were insignificant (P=0.1684 and P=0.3794, respectively). We conclude that reductive amination is the superior method to prepare the S. Typhi OSP glycoconjugate. Moreover, rEPA was a better carrier protein than HSA. Thus OSP-rEPA conjugate seems to be efficacious typhoid vaccines candidate, it may be evaluated further and recommended for the clinical trials.
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Affiliation(s)
- M Salman
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Canada; Health Biotechnology Division, National Institute for Biotechnology, Faisalabad, Pakistan; Department of Microbiology and Biotechnology, Abasyn University, Peshawar, Pakistan.
| | - F St Michael
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Canada
| | - A Ali
- Health Biotechnology Division, National Institute for Biotechnology, Faisalabad, Pakistan
| | - A Jabbar
- Department of Biotechnology, Mirpur University of Science & Technology (MUST), Mirpur, AJK, Pakistan
| | - C Cairns
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Canada
| | - A C Hayes
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Canada
| | - M Rahman
- Health Biotechnology Division, National Institute for Biotechnology, Faisalabad, Pakistan
| | - M Iqbal
- Health Biotechnology Division, National Institute for Biotechnology, Faisalabad, Pakistan
| | - A Haque
- Faculty of Life Sciences, University of Faisalabad, Faisalabad, Pakistan
| | - A D Cox
- Vaccine Program, Human Health Therapeutics Portfolio, National Research Council, Ottawa, Canada.
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17
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Giannelli C, Cappelletti E, Di Benedetto R, Pippi F, Arcuri M, Di Cioccio V, Martin L, Saul A, Micoli F. Determination of free polysaccharide in Vi glycoconjugate vaccine against typhoid fever. J Pharm Biomed Anal 2017; 139:143-147. [DOI: 10.1016/j.jpba.2017.02.042] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 02/13/2017] [Accepted: 02/20/2017] [Indexed: 10/20/2022]
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18
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Ghosh T, Misra AK. Synthesis of the Heptasaccharide Repeating Unit of the Cell Wall O-Polysaccharide of Enterotoxigenic Escherichia coli O139. ChemistryOpen 2016; 5:43-6. [PMID: 27308210 PMCID: PMC4906484 DOI: 10.1002/open.201500164] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Indexed: 11/10/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) like the O139 strain are mostly responsible for traveler's diarrhea and causes diseases in pigs, cattle, and poultry. A convenient synthetic strategy was developed for the synthesis of the heptasaccharide repeating unit of the cell wall lipopolysaccharide of the E. coli O139 strain. The p-methoxybenzyl (PMB) group was used as a temporary protecting group which was removed in situ under the glycosylation conditions by changing the reaction temperature during the synthesis of the target compound. All glycosylation steps gave high yields with good stereoselectivity. A (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-mediated selective oxidation of the primary hydroxyl group was carried out using a biphasic reaction condition at the late stage of the synthesis. Such synthetic oligosaccharides could later be effectively conjugated with proteins to prepare glycoconjugate derivatives as vaccine candidates.
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Affiliation(s)
- Tamashree Ghosh
- Division of Molecular MedicineBose InstituteP-1/12, C.I.T. Scheme VII MKolkata700054India
| | - Anup Kumar Misra
- Division of Molecular MedicineBose InstituteP-1/12, C.I.T. Scheme VII MKolkata700054India
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19
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Brazilian meningococcal C conjugate vaccine: Scaling up studies. Vaccine 2015; 33:4281-7. [DOI: 10.1016/j.vaccine.2015.03.097] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Revised: 02/21/2015] [Accepted: 03/24/2015] [Indexed: 11/21/2022]
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20
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Gunn JS, Marshall JM, Baker S, Dongol S, Charles RC, Ryan ET. Salmonella chronic carriage: epidemiology, diagnosis, and gallbladder persistence. Trends Microbiol 2014; 22:648-55. [PMID: 25065707 PMCID: PMC4252485 DOI: 10.1016/j.tim.2014.06.007] [Citation(s) in RCA: 174] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 12/13/2022]
Abstract
Typhoid (enteric fever) remains a major cause of morbidity and mortality worldwide, causing over 21 million new infections annually, with the majority of deaths occurring in young children. Because typhoid fever-causing Salmonella have no known environmental reservoir, the chronic, asymptomatic carrier state is thought to be a key feature of continued maintenance of the bacterium within human populations. Despite the importance of this disease to public health, our understanding of the molecular mechanisms that catalyze carriage, as well as our ability to reliably identify and treat the Salmonella carrier state, have only recently begun to advance.
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Affiliation(s)
- John S Gunn
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, OH, USA.
| | - Joanna M Marshall
- Department of Microbial Infection and Immunity, Center for Microbial Interface Biology, The Ohio State University, OH, USA
| | - Stephen Baker
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam; Centre for Tropical Medicine, Oxford University, Oxford, United Kingdom; The London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Sabina Dongol
- Oxford University Clinical Research Unit, Patan Academy of Health Sciences, Kathmandu, Nepal
| | - Richelle C Charles
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA
| | - Edward T Ryan
- Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA; Department of Medicine, Harvard Medical School, Boston, MA, USA; Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, MA, USA
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21
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MacLennan CA, Martin LB, Micoli F. Vaccines against invasive Salmonella disease: current status and future directions. Hum Vaccin Immunother 2014; 10:1478-93. [PMID: 24804797 PMCID: PMC4185946 DOI: 10.4161/hv.29054] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Though primarily enteric pathogens, Salmonellae are responsible for a considerable yet under-appreciated global burden of invasive disease. In South and South-East Asia, this manifests as enteric fever caused by serovars Typhi and Paratyphi A. In sub-Saharan Africa, a similar disease burden results from invasive nontyphoidal Salmonellae, principally serovars Typhimurium and Enteritidis. The existing Ty21a live-attenuated and Vi capsular polysaccharide vaccines target S. Typhi and are not effective in young children where the burden of invasive Salmonella disease is highest. After years of lack of investment in new Salmonella vaccines, recent times have seen increased interest in the area led by emerging-market manufacturers, global health vaccine institutes and academic partners. New glycoconjugate vaccines against S. Typhi are becoming available with similar vaccines against other invasive serovars in development. With other new vaccines under investigation, including live-attenuated, protein-based and GMMA vaccines, now is an exciting time for the Salmonella vaccine field.
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Affiliation(s)
- Calman A MacLennan
- Novartis Vaccines Institute for Global Health; Siena, Italy; Medical Research Council Centre for Immune Regulation and Clinical Immunology Service; Institute of Biomedical Research, School of Immunity and Infection; College of Medicine and Dental Sciences; University of Birmingham; Birmingham, UK
| | - Laura B Martin
- Novartis Vaccines Institute for Global Health; Siena, Italy
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22
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23
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Bhutta ZA, Capeding MR, Bavdekar A, Marchetti E, Ariff S, Soofi SB, Anemona A, Habib MA, Alberto E, Juvekar S, Khan RMQ, Marhaba R, Ali N, Malubay N, Kawade A, Saul A, Martin LB, Podda A. Immunogenicity and safety of the Vi-CRM197 conjugate vaccine against typhoid fever in adults, children, and infants in south and southeast Asia: results from two randomised, observer-blind, age de-escalation, phase 2 trials. THE LANCET. INFECTIOUS DISEASES 2013; 14:119-29. [PMID: 24290843 DOI: 10.1016/s1473-3099(13)70241-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND Typhoid vaccination is a public health priority in developing countries where young children are greatly affected by typhoid fever. Because present vaccines are not recommended for children younger than 2 years, the Novartis Vaccines Institute for Global Health developed a conjugate vaccine (Vi-CRM197) for infant immunisation. We aimed to assess the immunogenicity and safety of Vi-CRM197 in participants of various ages in endemic countries in south and southeast Asia. METHODS We did two randomised, observer-blind, age de-escalation, phase 2 trials at two sites in Pakistan and India (study A), and at one site in the Philippines (study B), between March 2, 2011, and Aug 9, 2012. Adults aged 18-45 years, children aged 24-59 months, older infants aged 9-12 months, and infants aged 6-8 weeks were randomly assigned (1:1) with a computer-generated randomisation list (block size of four) to receive either 5 μg Vi-CRM197 or 25 μg Vi-polysaccharide vaccine (or 13-valent pneumococcal conjugate vaccine in children younger than 2 years). Both infant populations received Vi-CRM197 concomitantly with vaccines of the Expanded Programme on Immunization (EPI), according to WHO schedule. With the exception of designated study site personnel responsible for vaccine preparation, study investigators, those assessing outcomes, and data analysts were masked to treatment allocation. We specified no a-priori null hypothesis for the immunogenicity or safety objectives and all analyses were descriptive. Analyses were by modified intention-to-treat. These studies are registered with ClinicalTrials.gov, numbers NCT01229176 and NCT01437267. FINDINGS 320 participants were enrolled and vaccinated in the two trials: 200 in study A (all age groups) and 120 in study B (children and infants only), of whom 317 (99%) were included in the modified intention-to-treat analysis. One dose of Vi-CRM197 significantly increased concentrations of anti-Vi antibody in adults (from 113 U/mL [95% CI 67-190] to 208 U/mL [117-369]), children (201 U/mL [138-294] to 368 U/mL [234-580]), and older infants (179 U/mL [129-250] to 249 U/mL [130-477]). However, in children and older infants, a second dose of conjugate vaccine had no incremental effect on antibody titres and, at all ages, concentrations of antibodies increased substantially 6 months after vaccination (from 55 U/mL [33-94] to 63 U/mL [35-114] in adults, from 23 U/mL [15-34] to 51 U/mL [34-76] in children, and from 21 U/mL [14-31] to 22 U/mL [14-33] in older infants). Immune response in infants aged 6-8 weeks was lower than that in older participants and, 6 months after third vaccination, antibody concentrations were significantly higher than pre-vaccination concentrations in Filipino (21 U/mL [16-28] vs 2.88 U/mL [1.95-4.25]), but not Pakistani (3.76 U/mL [2.77-5.08] vs 2.77 U/mL [2.1-3.66]), infants. Vi-CRM197 was safe and well tolerated and did not induce any significant interference with EPI vaccines. No deaths or vaccine-related serious adverse events were reported throughout the studies. INTERPRETATION Vi-CRM197 is safe and immunogenic in endemic populations of all ages. Given at 9 months of age, concomitantly with measles vaccine, Vi-CRM197 shows a promise for potential inclusion in EPI schedules of countries endemic for typhoid. An apparent absence of booster response and a reduction in antibody titres 6 months after immunisation should be further investigated, but data show that an immunogenic typhoid vaccine can be safely delivered to infants during EPI visits recommended by WHO. FUNDING Sclavo Vaccines Association and Regione Toscana.
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Affiliation(s)
- Zulfiqar A Bhutta
- Department of Pediatrics and Child Health, Division of Women and Child Health, Aga Khan University, Karachi, Pakistan
| | | | - Ashish Bavdekar
- King Edward Memorial Hospital Research Centre, Rasta Peth, Pune, India
| | | | - Shabina Ariff
- Novartis Vaccines Institute for Global Health, Siena, Italy
| | - Sajid B Soofi
- Department of Pediatrics and Child Health, Division of Women and Child Health, Aga Khan University, Karachi, Pakistan
| | | | - Muhammad A Habib
- Department of Pediatrics and Child Health, Division of Women and Child Health, Aga Khan University, Karachi, Pakistan
| | - Edison Alberto
- Research Institute for Tropical Medicine, Manila, Philippines
| | - Sanjay Juvekar
- King Edward Memorial Hospital Research Centre, Rasta Peth, Pune, India
| | | | - Rachid Marhaba
- Novartis Vaccines and Diagnostics Human Serology Laboratories, Marburg, Germany
| | - Noshad Ali
- Department of Pediatrics and Child Health, Division of Women and Child Health, Aga Khan University, Karachi, Pakistan
| | - Nelia Malubay
- Research Institute for Tropical Medicine, Manila, Philippines
| | - Anand Kawade
- King Edward Memorial Hospital Research Centre, Rasta Peth, Pune, India
| | - Allan Saul
- Novartis Vaccines Institute for Global Health, Siena, Italy
| | - Laura B Martin
- Novartis Vaccines Institute for Global Health, Siena, Italy
| | - Audino Podda
- Novartis Vaccines Institute for Global Health, Siena, Italy.
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Development of a glycoconjugate vaccine to prevent meningitis in Africa caused by meningococcal serogroup X. Proc Natl Acad Sci U S A 2013; 110:19077-82. [PMID: 24191022 DOI: 10.1073/pnas.1314476110] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Neisseria meningitidis is a major cause of bacterial meningitis worldwide, especially in the African meningitis belt, and has a high associated mortality. The meningococcal serogroups A, W, and X have been responsible for epidemics and almost all cases of meningococcal meningitis in the meningitis belt over the past 12 y. Currently no vaccine is available against meningococcal X (MenX). Because the development of a new vaccine through to licensure takes many years, this leaves Africa vulnerable to new epidemics of MenX meningitis at a time when the epidemiology of meningococcal meningitis on the continent is changing rapidly, following the recent introduction of a glycoconjugate vaccine against serogroup A. Here, we report the development of candidate glycoconjugate vaccines against MenX and preclinical data from their use in animal studies. Following optimization of growth conditions of our seed MenX strain for polysaccharide (PS) production, a scalable purification process was developed yielding high amounts of pure MenX PS. Different glycoconjugates were synthesized by coupling MenX oligosaccharides of varying chain length to CRM197 as carrier protein. Analytical methods were developed for in-process control and determination of purity and consistency of the vaccines. All conjugates induced high anti-MenX PS IgG titers in mice. Antibodies were strongly bactericidal against African MenX isolates. These findings support the further development of glycoconjugate vaccines against MenX and their assessment in clinical trials to produce a vaccine against the one cause of epidemic meningococcal meningitis that currently cannot be prevented by available vaccines.
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Abstract
Low-income countries typically lag behind industrialised nations, where the introduction of new vaccines is commonly tailored to the pressures of the commercial market. Happily in recent years this paradigm has started to change with the introduction of a univalent meningococcal A conjugate vaccine that is specifically targeted for the prevention of epidemic meningitis in Africa. The declaration of the 2010s as a New Decade of Vaccines, together with Millennium Development Goals 4 and 5, provide a strong mandate for a new approach to the development of vaccines for low-income countries, so that there has never been a more exciting time to work in this field. This review considers the opportunities and challenges of developing these new vaccines in the context of innovations in vaccinology, the need to induce protective immunity in the populations at risk and the requirement for strong partnership between the countries that will use these vaccines and different elements of the vaccine industry.
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26
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O'Shaughnessy CM, Micoli F, Gavini M, Goodall M, Cobbold M, Saul A, MacLennan CA. Purification of antibodies to O antigen of Salmonella Typhimurium from human serum by affinity chromatography. J Immunol Methods 2013; 387:199-210. [DOI: 10.1016/j.jim.2012.10.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Revised: 10/09/2012] [Accepted: 10/11/2012] [Indexed: 10/27/2022]
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Abstract
PURPOSE OF REVIEW This review summarizes the recent advances in vaccination against Salmonella enterica serovar Typhi and highlights the data supporting the development of next generation vaccines to address paratyphoid fever and invasive nontyphoidal Salmonella (iNTS) disease. RECENT FINDINGS There has been increasing awareness of the disease burden caused by S. Typhi particularly in Africa and greater recognition of S. Paratyphi A's contribution to enteric fever episodes throughout Asia. Groups have been working to improve the existing typhoid vaccines and provide comprehensive data on the feasibility of their implementation in endemic settings. These data have resulted in modifications to the recommendations for typhoid vaccination in traveller markets and endemic settings, and has also led to the development of S. Paratyphi A vaccine components that can be combined with existing typhoid vaccines to generate bivalent formulations against enteric fever. The epidemiology of iNTS serovars as cause of appreciable morbidity and mortality in Africa, and the need for vaccines, has also become more widely appreciated. SUMMARY Current typhoid vaccines, although moderately effective for short periods of time, cannot be used in all age groups and only target one of the clinically relevant Salmonella serovars. Greater effort must be placed on the development and implementation of improved vaccines for the disease burden resulting from Typhi, Paratyphi A or iNTS infections.
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Berti F, Romano MR, Micoli F, Pinto V, Cappelletti E, Gavini M, Proietti D, Pluschke G, MacLennan CA, Costantino P. Relative stability of meningococcal serogroup A and X polysaccharides. Vaccine 2012; 30:6409-15. [PMID: 22921741 DOI: 10.1016/j.vaccine.2012.08.021] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2012] [Revised: 07/02/2012] [Accepted: 08/11/2012] [Indexed: 10/28/2022]
Abstract
Prior to the introduction of the MenAfriVac™ serogroup A glycoconjugate vaccine in September 2010, serogroup A was the major epidemic disease-causing meningococcal serogroup in the African meningitis belt. However, recently serogroup X meningococcal (MenX) disease has received increased attention because of outbreaks recorded in this region, with increased endemic levels of MenX disease over the past 2 years. Whereas polysaccharide-protein conjugate vaccines against meningococcal serogroups A, C, W and Y (MenA, MenC, MenW, MenY) are on the market, a vaccine able to protect against MenX has never been achieved. The structure of serogroup A, C, W and Y meningococcal polysaccharides has been already fully elucidated by NMR. MenX capsular polysaccharide (MenX CPS) structure is also documented but fewer characterization data have been published. We have applied here (1)H NMR, (31)P NMR and HPLC to evaluate the stability of MenX CPS in aqueous solution as compared to MenA capsular polysaccharide (MenA CPS). The stability study demonstrated that MenA CPS is more susceptible to hydrolytic degradation than MenX CPS. The different stereochemistry of the N-acetyl group at position C(2) of mannosamine (MenA CPS) and glucosamine (MenX CPS) respectively might play a fundamental role in this susceptibility to polysaccharide chain degradation. The satisfactory stability of MenX CPS predicts the possibility that a stable fully-liquid MenX polysaccharide or glycoconjugate vaccine could be developed.
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Affiliation(s)
- F Berti
- Novartis Vaccines, Via Fiorentina 1, I-53100 Siena, Italy.
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29
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Immunization with the conjugate vaccine Vi-CRM₁₉₇ against Salmonella typhi induces Vi-specific mucosal and systemic immune responses in mice. Vaccine 2012; 30:6111-4. [PMID: 22705173 DOI: 10.1016/j.vaccine.2012.05.081] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Revised: 05/19/2012] [Accepted: 05/30/2012] [Indexed: 11/21/2022]
Abstract
Typhoid fever is a public health problem, especially among young children in developing countries. To address this need, a glycoconjugate vaccine Vi-CRM₁₉₇, composed of the polysaccharide antigen Vi covalently conjugated to the non-toxic mutant of diphtheria toxin CRM₁₉₇, is under development. Here, we assessed the antibody and cellular responses, both local and systemic, following subcutaneous injection of Vi-CRM₁₉₇. The glycoconjugate elicited Vi-specific serum IgG titers significantly higher than unconjugated Vi, with prevalence of IgG1 that persisted for at least 60 days after immunization. Vi-specific IgG, but not IgA, were present in intestinal washes. Lymphocytes proliferation after restimulation with Vi-CRM₁₉₇ was observed in spleen and mesenteric lymph nodes. These data confirm the immunogenicity of Vi-CRM₁₉₇ and demonstrate that the vaccine-specific antibody and cellular immune responses are present also in the intestinal tract, thus strengthening the suitability of Vi-CRM₁₉₇ as a promising candidate vaccine against Salmonella Typhi.
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