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Martin LB, Tack B, Marchello CS, Sikorski MJ, Owusu-Dabo E, Nyirenda T, Mogasale V, Crump JA. Vaccine value profile for invasive non-typhoidal Salmonella disease. Vaccine 2024; 42:S101-S124. [PMID: 39003017 DOI: 10.1016/j.vaccine.2024.04.045] [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: 10/02/2022] [Revised: 04/12/2024] [Accepted: 04/14/2024] [Indexed: 07/15/2024]
Abstract
Invasive non-typhoidal Salmonella (iNTS) disease is an under-recognized high-burden disease causing major health and socioeconomic issues in sub-Saharan Africa (sSA), predominantly among immune-naïve infants and young children, including those with recognized comorbidities such as HIV infection. iNTS disease is primarily caused by Salmonella enterica serovar Typhimurium sequence type (ST) 313 and 'African-restricted clades' of Salmonella Enteritidis ST11 that have emerged across the African continent as a series of epidemics associated with acquisition of new antimicrobial resistance. Due to genotypes with a high prevalence of antimicrobial resistance and scarcity of therapeutic options, these NTS serovars are designated by the World Health Organization as a priority pathogen for research and development of interventions, including vaccines, to address and reduce NTS associated bacteremia and meningitis in sSA. Novel and traditional vaccine technologies are being applied to develop vaccines against iNTS disease, and the results of the first clinical trials in the infant target population should become available in the near future. The "Vaccine Value Profile" (VVP) addresses information related predominantly to invasive disease caused by Salmonella Enteritidis and Salmonella Typhimurium prevalent in sSA. Information is included on stand-alone iNTS disease candidate vaccines and candidate vaccines targeting iNTS disease combined with another invasive serotype, Salmonella Typhi, that is also common across sSA. Out of scope for the first version of this VVP is a wider discussion on either diarrheagenic NTS disease (dNTS) also associated with Salmonella Enteritidis and Salmonella Typhimurium or the development of a multivalent Salmonella vaccines targeting key serovars for use globally. This VVP for vaccines to prevent iNTS disease is intended to provide a high-level, holistic assessment of the information and data that are currently available to inform the potential public health, economic, and societal value of pipeline vaccines and vaccine-like products. Future versions of this VVP will be updated to reflect ongoing activities such as vaccine development strategies and a "Full Vaccine Value Assessment" that will inform the value proposition of an iNTS disease vaccine. This VVP was developed by a working group of subject matter experts from academia, non-profit organizations, public private partnerships, and multi-lateral organizations, and in collaboration with stakeholders from the World Health Organization African Region. All contributors have extensive expertise on various elements of the iNTS disease 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)
| | - Bieke Tack
- Department of Clinical Sciences, Institute of Tropical Medicine Antwerp, Belgium and Department of Microbiology, Immunology and Transplantation, KU Leuven, Belgium.
| | | | - Michael J Sikorski
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, USA.
| | | | | | | | - John A Crump
- Centre for International Health, University of Otago, New Zealand.
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Nhung NT, Phu DH, Carrique-Mas JJ, Padungtod P. A review and meta-analysis of non-typhoidal Salmonella in Vietnam: Challenges to the control and antimicrobial resistance traits of a neglected zoonotic pathogen. One Health 2024; 18:100698. [PMID: 38468610 PMCID: PMC10926303 DOI: 10.1016/j.onehlt.2024.100698] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Revised: 12/18/2023] [Accepted: 02/29/2024] [Indexed: 03/13/2024] Open
Abstract
Non-typhoidal Salmonella (NTS) is a food-borne zoonotic pathogen with important implications for human health. Despite its importance, the burden of NTS infections in Vietnam is unknown. We conducted a systematic review and a meta-analysis to describe the prevalence and phenotypic antimicrobial resistance (AMR) for NTS over time in Vietnam. Following PRISMA guidelines, we identified 72 studies from PubMed and Google Scholar containing data relevant to 'Salmonella', 'Salmonellosis', and 'Vietnam', or 'Viet Nam'. Of those, forty-two papers reporting prevalence of NTS, and twenty-six including data on phenotypic resistance were selected for meta-analysis. The prevalence of NTS ranged from 2% to 5% in humans and from 30% to 41% in samples from animals and the farm/slaughterhouse environment. Between 2000 and 2020 we observed a 27.3% (p = 0.044) increase in absolute terms in prevalence among individuals with enteric diseases and a 12.0% (p = 0.047) increase in aquaculture/seafood samples. The most commonly serovars identified across studies included S. Weltevreden (12.0%), followed by S. Typhimurium (10.1%), S. Derby (6.4%), S. London (5.8%), S. Anatum (4.4%), S. Rissen (3.9%), S. Enteritidis (3.7%), S. Albany (3.3%) and S. 4,[5],12:i:- (3.0%). Over the same period, there was an increasing trend in the pooled AMR prevalence for quinolones (15.6% relative increase), 3rd-, 4th-, and 5th-generation cephalosporins (23.7%), penicillins (16.1%), tetracyclines (12.9%), sulfonamides (8.8%), amphenicol (17.8%), and multidrug resistance (11.4%) (all p ≤ 0.014). A broad range of AMR genes (ARGs) were detected in both human and animal populations. The observed prevalence and AMR trends in Vietnam underscore the need of adopting a One Health strategy encompassing surveillance systems, research initiatives, and awareness campaigns to effectively address the challenges posed by NTS.
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Affiliation(s)
- Nguyen Thi Nhung
- Oxford University Clinical Research Unit, Ho Chi Minh City, Viet Nam
| | - Doan Hoang Phu
- Faculty of Animal Science and Veterinary Medicine, Nong Lam University, Ho Chi Minh City, Viet Nam
- Doctoral Program in Health Sciences, College of Graduate Studies, Walailak University, Nakhon Si Thammarat, Thailand
| | | | - Pawin Padungtod
- Food and Agriculture Organization of the United Nations (FAO), Hanoi, Viet Nam
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Lipman DJ, Cherry JL, Strain E, Agarwala R, Musser SM. Genomic perspectives on foodborne illness. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.05.16.24307425. [PMID: 38903069 PMCID: PMC11188124 DOI: 10.1101/2024.05.16.24307425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/22/2024]
Abstract
Whole-genome sequencing of bacterial pathogens is used by public health agencies to link cases of food poisoning caused by the same source of contamination. The vast majority of these appear to be sporadic cases associated with small contamination episodes and do not trigger investigations. We analyzed clusters of sequenced clinical isolates of Salmonella, Escherichia coli, Campylobacter, and Listeria that differ by only a small number of mutations to provide a new understanding of the underlying contamination episodes. These analyses provide new evidence that the youngest age groups have greater susceptibility to infection from Salmonella, Escherichia coli, and Campylobacter than older age groups. This age bias is weaker for the common Salmonella serovar Enteritidis than Salmonella in general. Analysis of these clusters reveals significant regional variations in relative frequencies of Salmonella serovars across the United States. A large fraction of the contamination episodes causing sickness appear to have long duration. For example, 50% of the Salmonella cases are in clusters that persist for almost three years. For all four pathogen species, the majority of the cases were part of genetic clusters with illnesses in multiple states and likely to be caused by contaminated commercially distributed foods. The vast majority of Salmonella cases among infants < 6 months of age appear to be caused by cross-contamination from foods consumed by older age groups or by environmental bacteria rather than infant formula contaminated at production sites.
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Affiliation(s)
- David J. Lipman
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, College Park, MD, USA
| | - Joshua L. Cherry
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
- Division of International Epidemiology and Population Studies, Fogarty International Center, National Institutes of Health, Bethesda, Maryland, USA
| | - Errol Strain
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, College Park, MD, USA
| | - Richa Agarwala
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, Maryland, USA
| | - Steven M. Musser
- Center for Food Safety and Applied Nutrition, Office of Regulatory Science, College Park, MD, USA
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Dale H, Chirwa E, Patel P, Makuta G, Mwakiseghile F, Misiri T, Kadwala I, Mbewe M, Banda H, Silungwe N, Chizani K, Kambiya P, Henrion M, French N, Nyirenda T, Gordon M. Understanding the epidemiology of iNTS disease in Africa in preparation for future iNTS- vaccine studies in endemic countries: Seroepidemiology in Africa of iNTS (SAiNTS) Study Protocol [Version 9.0]. Wellcome Open Res 2023. [DOI: 10.12688/wellcomeopenres.18054.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Background: Non-typhoidal Salmonella (NTS) are a major cause of bloodstream infections amongst children in sub-Saharan Africa. A clear understanding of the seroepidemiology and correlates of protection for invasive NTS (iNTS) in relation to key risk factors (malaria, anaemia, malnutrition) in children in Africa is needed to inform strategies for disease control including vaccine implementation. Methodology: The SAiNTS study is a prospective community cohort study with paired serology samples from 2500 children 0-5 years at baseline and three months to measure age-stratified acquisition of lipopolysaccharide (LPS) O-antigen antibody (IgG) and serum bactericidal activity to the main serovars causing iNTS (Salmonella typhimurium and S. enteritidis). Children are selected from mapped and censused randomly selected households in Chikwawa, Malawi; an area with substantial malaria burden. The sampling framework is set within a malaria vaccination (RTS,S/ AS01) phase 4 cluster randomized trial (EPIMAL), allowing exploration of the impact of malaria vaccination on acquisition of immunity to NTS. Data on risk factors for invasive disease: malaria, anaemia and malnutrition as well as indicators of socioeconomic status and water and sanitation, will be collected using rapid diagnostic tests, anthropometry and electronic CRF’s. Stool sample analysis includes NTS culture and pan-Salmonella polymerase chain reaction to assess enteric exposure and biomarkers of environmental enteric dysfunction. Cases with iNTS disease will be followed up for comparison with community controls. Conclusions: The final cohort of 2500 children will allow investigation into the impact of risk factors for iNTS on the acquisition of immunity in children 0-5 years in an endemic setting, including comparisons to partner sero-epidemiology studies in three other sub-Saharan African sites. The data generated will be key to informing iNTS disease control measures including targeted risk factor interventions and vaccine implementation through investigation of correlates of protection and identifying windows of immune susceptibility in at-risk populations.
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Elias SC, Muthumbi E, Mwanzu A, Wanjiku P, Mutiso A, Simon R, MacLennan CA. Complementary measurement of nontyphoidal Salmonella-specific IgG and IgA antibodies in oral fluid and serum. Heliyon 2023; 9:e12071. [PMID: 36704288 PMCID: PMC9871079 DOI: 10.1016/j.heliyon.2022.e12071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 10/07/2022] [Accepted: 11/25/2022] [Indexed: 12/23/2022] Open
Abstract
Objectives Immuno-epidemiological studies of orally acquired, enteric pathogens such as nontyphoidal Salmonella (NTS) often focus on serological measures of immunity, ignoring potentially relevant oral mucosal responses. In this study we sought to assess the levels and detectability of both oral fluid and serum IgG and IgA to NTS antigens, in endemic and non-endemic populations. Methods IgG and IgA antibodies specific for Salmonella Typhimurium and Salmonella Enteritidis O antigen and phase 1 flagellin were assessed using Enzyme Linked Immunosorbent Assay (ELISA). Paired oral fluid and serum samples were collected from groups of 50 UK adults, Kenyan adults and Kenyan infants. Additionally, oral fluid alone was collected from 304 Kenyan individuals across a range of ages. Results Antigen-specific IgG and IgA was detectable in the oral fluid of both adults and infants. Oral fluid antibody increased with age, peaking in adulthood for both IgG and IgA but a separate peak was also observed for IgA in infants. Oral fluid and serum responses correlated for IgG but not IgA. Despite standardised collection the relationship between oral fluid volume and antibody levels varied with age and country of origin. Conclusions Measurement of NTS-specific oral fluid antibody can be used to complement measurement of serum antibody. For IgA in particular, oral fluid may offer insights into how protective immunity to NTS changes as individuals transition with age, from maternal to acquired systemic and mucosal immunity. This may prove useful in helping to guide future vaccine design.
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Affiliation(s)
- Sean C. Elias
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, UK
- Corresponding author.
| | - Esther Muthumbi
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
- London School of Hygiene & Tropical Medicine, UK
| | - Alfred Mwanzu
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
| | | | - Agnes Mutiso
- KEMRI-Wellcome Trust Research Programme, Kilifi, Kenya
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MacLennan CA. The Background, Role and Approach for Development of a Controlled Human Infection Model for Nontyphoidal Salmonella. Curr Top Microbiol Immunol 2021. [PMID: 34958419 DOI: 10.1007/82_2021_246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nontyphoidal Salmonella (NTS) is responsible for a major global burden of disease and economic loss, particularly in low- and middle-income countries. It is designated a priority pathogen by the WHO for vaccine development and, with new impetus from vaccine developers, the establishment of an NTS controlled human infection model (CHIM) is timely and valuable. The broadly dichotomous clinical presentations of diarrhoea and invasive disease, commonly bacteraemia, present significant challenges to the development of an NTS CHIM. Nevertheless, if successful, such a CHIM will be invaluable for understanding the pathogenesis of NTS disease, identifying correlates of protection and advancing candidate vaccines towards licensure. This article describes the background case for a CHIM for NTS, the role of such a CHIM and outlines a potential approach to its development.
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Affiliation(s)
- Calman A MacLennan
- Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, OX3 7DQ, UK.
- Bill & Melinda Gates Foundation, 62 Buckingham Gate, London, SW16AJ, UK.
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Ndungo E, Andronescu LR, Buchwald AG, Lemme-Dumit JM, Mawindo P, Kapoor N, Fairman J, Laufer MK, Pasetti MF. Repertoire of Naturally Acquired Maternal Antibodies Transferred to Infants for Protection Against Shigellosis. Front Immunol 2021; 12:725129. [PMID: 34721387 PMCID: PMC8554191 DOI: 10.3389/fimmu.2021.725129] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 09/27/2021] [Indexed: 11/13/2022] Open
Abstract
Shigella is the second leading cause of diarrheal diseases, accounting for >200,000 infections and >50,000 deaths in children under 5 years of age annually worldwide. The incidence of Shigella-induced diarrhea is relatively low during the first year of life and increases substantially, reaching its peak between 11 to 24 months of age. This epidemiological trend hints at an early protective immunity of maternal origin and an increase in disease incidence when maternally acquired immunity wanes. The magnitude, type, antigenic diversity, and antimicrobial activity of maternal antibodies transferred via placenta that can prevent shigellosis during early infancy are not known. To address this knowledge gap, Shigella-specific antibodies directed against the lipopolysaccharide (LPS) and virulence factors (IpaB, IpaC, IpaD, IpaH, and VirG), and antibody-mediated serum bactericidal (SBA) and opsonophagocytic killing antibody (OPKA) activity were measured in maternal and cord blood sera from a longitudinal cohort of mother-infant pairs living in rural Malawi. Protein-specific (very high levels) and Shigella LPS IgG were detected in maternal and cord blood sera; efficiency of placental transfer was 100% and 60%, respectively, and had preferential IgG subclass distribution (protein-specific IgG1 > LPS-specific IgG2). In contrast, SBA and OPKA activity in cord blood was substantially lower as compared to maternal serum and varied among Shigella serotypes. LPS was identified as the primary target of SBA and OPKA activity. Maternal sera had remarkably elevated Shigella flexneri 2a LPS IgM, indicative of recent exposure. Our study revealed a broad repertoire of maternally acquired antibodies in infants living in a Shigella-endemic region and highlights the abundance of protein-specific antibodies and their likely contribution to disease prevention during the first months of life. These results contribute new knowledge on maternal infant immunity and target antigens that can inform the development of vaccines or therapeutics that can extend protection after maternally transferred immunity wanes.
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Affiliation(s)
- Esther Ndungo
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Liana R. Andronescu
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Andrea G. Buchwald
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Jose M. Lemme-Dumit
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Patricia Mawindo
- Blantyre Malaria Project, University of Malawi College of Medicine, Blantyre, Malawi
| | | | | | - Miriam K. Laufer
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Marcela F. Pasetti
- Department of Pediatrics, Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD, United States
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Chisenga CC, Bosomprah S, Simuyandi M, Mwila-Kazimbaya K, Chilyabanyama ON, Laban NM, Bialik A, Asato V, Meron-Sudai S, Frankel G, Cohen D, Chilengi R. Shigella-specific antibodies in the first year of life among Zambian infants: A longitudinal cohort study. PLoS One 2021; 16:e0252222. [PMID: 34043697 PMCID: PMC8158915 DOI: 10.1371/journal.pone.0252222] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 05/11/2021] [Indexed: 01/02/2023] Open
Abstract
Introduction Shigellosis, is a leading cause of moderate-to-severe diarrhoea and related mortality in young children in low and middle income countries (LMICs). Knowledge on naturally acquired immunity can support the development of Shigella candidate vaccines mostly needed in LMICs. We aimed to quantify Shigella-specific antibodies of maternal origin and those naturally acquired in Zambian infants. Methods Plasma samples collected from infants at age 6, 14 and 52-weeks were tested for Shigella (S. sonnei and S. flexneri 2a) lipopolysaccharide (LPS) antigen specific immunoglobulin G (IgG) and A (IgA) by enzyme-linked immunosorbent assay. Results At 6 weeks infant age, the IgG geometric mean titres (GMT) against S. sonnei (N = 159) and S. flexneri 2a (N = 135) LPS were 311 (95% CI 259–372) and 446 (95% CI 343–580) respectively. By 14 weeks, a decline in IgG GMT was observed for both S. sonnei to 104 (95% CI 88–124), and S. flexneri 2a to 183 (95% CI 147–230). Both S. sonnei and S. flexneri 2a specific IgG GMT continued to decrease by 52 weeks infant age when compared to 6 weeks. In 27% and 8% of infants a significant rise in titre (4 fold and greater) against S. flexneri 2a and S. sonnei LPS, respectively, was detected between the ages of 14 and 52 weeks. IgA levels against both species LPS were very low at 6 and 14 weeks and raised significantly against S. flexneri 2a and S. sonnei LPS in 29% and 10% of the infants, respectively. Conclusion In our setting, transplacental IgG anti-Shigella LPS is present at high levels in early infancy, and begins to decrease by age 14 weeks. Our results are consistent with early exposure to Shigella and indicate naturally acquired IgG and IgA antibodies to S. flexneri 2a and S. sonnei LPS in part of infants between 14 and 52 weeks of age. These results suggest that a potential timing of vaccination would be after 14 and before 52 weeks of age to ensure early infant protection against shigellosis.
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Affiliation(s)
| | - Samuel Bosomprah
- Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
- Department of Biostatistics, School of Public Health, University of Ghana, Accra, Ghana
| | | | | | | | - Natasha M. Laban
- Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
| | - Anya Bialik
- School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Valeria Asato
- School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Shiri Meron-Sudai
- School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Gad Frankel
- Imperial College London, London, United Kingdom
| | - Daniel Cohen
- School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Roma Chilengi
- Centre for Infectious Disease Research in Zambia, Lusaka, Zambia
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de Alwis R, Liang L, Taghavian O, Werner E, The HC, Thu TNH, Duong VT, Davies DH, Felgner PL, Baker S. The identification of novel immunogenic antigens as potential Shigella vaccine components. Genome Med 2021; 13:8. [PMID: 33451348 PMCID: PMC7809897 DOI: 10.1186/s13073-020-00824-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/18/2020] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Shigella is a major diarrheal pathogen for which there is presently no vaccine. Whole genome sequencing provides the ability to predict and derive novel antigens for use as vaccines. Here, we aimed to identify novel immunogenic Shigella antigens that could serve as Shigella vaccine candidates, either alone, or when conjugated to Shigella O-antigen. METHODS Using a reverse vaccinology approach, where genomic analysis informed the Shigella immunome via an antigen microarray, we aimed to identify novel immunogenic Shigella antigens. A core genome analysis of Shigella species, pathogenic and non-pathogenic Escherichia coli, led to the selection of 234 predicted immunogenic Shigella antigens. These antigens were expressed and probed with acute and convalescent serum from microbiologically confirmed Shigella infections. RESULTS Several Shigella antigens displayed IgG and IgA seroconversion, with no difference in sero-reactivity across by sex or age. IgG sero-reactivity to key Shigella antigens was observed at birth, indicating transplacental antibody transfer. Six antigens (FepA, EmrK, FhuA, MdtA, NlpB, and CjrA) were identified in in vivo testing as capable of producing binding IgG and complement-mediated bactericidal antibody. CONCLUSIONS These findings provide six novel immunogenic Shigella proteins that could serve as candidate vaccine antigens, species-specific carrier proteins, or targeted adjuvants.
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Affiliation(s)
- Ruklanthi de Alwis
- Program in Emerging Infectious Diseases, Duke-NUS Medical School, Singapore, Singapore
- Viral Research and Experimental Medicine Centre, SingHealth Duke-NUS Academic Medical Centre, Singapore, Singapore
| | - Li Liang
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Omid Taghavian
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Emma Werner
- Laboratory of Molecular Biology, Cambridge Biomedical Campus, Cambridge, UK
| | - Hao Chung The
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Trang Nguyen Hoang Thu
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Vu Thuy Duong
- The Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - D Huw Davies
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Philip L Felgner
- Vaccine Research & Development Center, School of Medicine, University of California Irvine, Irvine, CA, USA
| | - Stephen Baker
- Cambridge Institute of Therapeutic Immunology & Infectious Disease (CITIID), Level 5, Jeffery Cheah Biomedical Centre, Cambridge Biomedical Campus, University of Cambridge, Cambridge, CB2 0AW, UK.
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