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Raqib R. Bivalent conjugate vaccines for typhoid and paratyphoid fever. Lancet 2024; 403:1516-1517. [PMID: 38555929 DOI: 10.1016/s0140-6736(24)00461-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Accepted: 03/01/2024] [Indexed: 04/02/2024]
Affiliation(s)
- Rubhana Raqib
- Nutrition Research Division, International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka-1212, Bangladesh.
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Chaudhary S, Shah GS, Bhatta NK, Poudel P, Rai B, Uranw S, Tripathi PM, Khanal B, Ghimire A, Rai N, Gupta BP, Vemula S, Wartel TA, Sahastrabuddhe S, Saluja T. A randomized, observer-blind, controlled phase III clinical trial assessing safety and immunological non-inferiority of Vi-diphtheria toxoid versus Vi-tetanus toxoid typhoid conjugate vaccine in healthy volunteers in eastern Nepal. Hum Vaccin Immunother 2023; 19:2203634. [PMID: 37128723 PMCID: PMC10142305 DOI: 10.1080/21645515.2023.2203634] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/03/2023] Open
Abstract
Typhoid remains one of the major serious health concerns for children in developing countries. With extremely drug-resistant cases emerging, preventative measures like sanitation and vaccination, including typhoid conjugate vaccines (TCV) remain the mainstay in its prevention and control. Different types of TCVs are being developed to meet the global demand. This report outlines the results from a study done to assess the immunogenicity and safety of Vi-Diphtheria toxoid (Vi-DT) TCV in Nepal. The study was a randomized, active-controlled, immunological non-inferiority and safety study. Eligible participants from Sunsari and Morang districts of eastern Nepal were randomized into 4 study groups (A-D) within 3 age strata (6 months to <2 years, 2 to <18 years, and 18 to 45 years). Groups A to C received a single dose (25 μg) of Vi-DT test vaccine from any of the 3 lots, while group D received the comparator, Typbar-TCV®, Vi-tetanus toxoid (Vi-TT) vaccine (25 μg) in 1:1:1:1 ratio and evaluated at 4 weeks postvaccination with 6 months follow-up. Amongst 400 randomized participants, anti-Vi-IgG seroconversion rates for all age strata in Vi-DT pooled groups (A+B+C) were 100.00% (97.5% CI 98.34-100.00) vs 98.99% (97.5% CI 93.99-99.85) in Vi-TT group (D) at 4 weeks. Comparable safety events were reported between the groups. Three serious adverse events (1 in Vi-DT; 2 in Vi-TT group) were reported during the 6 months follow-up, none being related to the investigational product. Thus, Vi-DT vaccine is safe, immunogenic, and immunologically non-inferior to Vi-TT when analyzed at 4 weeks postvaccination.
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Affiliation(s)
- Shipra Chaudhary
- B P Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal
| | | | | | - Prakash Poudel
- B P Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal
| | - Basant Rai
- B P Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal
| | - Surendra Uranw
- B P Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal
| | | | - Basudha Khanal
- B P Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal
| | - Anup Ghimire
- B P Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal
| | - Nikita Rai
- B P Koirala Institute of Health Sciences (BPKIHS), Dharan, Nepal
| | | | | | - T Anh Wartel
- International Vaccine Institute (IVI), Seoul, Korea
| | | | - Tarun Saluja
- International Vaccine Institute (IVI), Seoul, Korea
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Abo YN, Jamrozik E, McCarthy JS, Roestenberg M, Steer AC, Osowicki J. Strategic and scientific contributions of human challenge trials for vaccine development: facts versus fantasy. THE LANCET. INFECTIOUS DISEASES 2023; 23:e533-e546. [PMID: 37573871 DOI: 10.1016/s1473-3099(23)00294-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/24/2023] [Accepted: 04/26/2023] [Indexed: 08/15/2023]
Abstract
The unprecedented speed of delivery of SARS-CoV-2 pandemic vaccines has redefined the limits for all vaccine development. Beyond the aspirational 100-day timeline for tomorrow's hypothetical pandemic vaccines, there is a sense of optimism that development of other high priority vaccines can be accelerated. Early in the COVID-19 pandemic, an intense and polarised academic and public discourse arose concerning the role of human challenge trials for vaccine development. A case was made for human challenge trials as a powerful tool to establish early proof-of-concept of vaccine efficacy in humans, inform vaccine down selection, and address crucial knowledge gaps regarding transmission, pathogenesis, and immune protection. We review the track record of human challenge trials contributing to the development of vaccines for 19 different pathogens and discuss relevant limitations, barriers, and pitfalls. This Review also highlights opportunities for efforts to broaden the scope and boost the effects of human challenge trials, to accelerate all vaccine development.
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Affiliation(s)
- Yara-Natalie Abo
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia.
| | - Euzebiusz Jamrozik
- Ethox and Pandemic Sciences Institute, Nuffield Department of Population Health, University of Oxford, Oxford, UK; Monash-WHO Collaborating Centre for Bioethics, Monash University, Melbourne, VIC, Australia
| | - James S McCarthy
- Department of Infectious Diseases, The University of Melbourne, Parkville, VIC, Australia; Victorian Infectious Diseases Services, Royal Melbourne Hospital, Parkville, VIC, Australia
| | - Meta Roestenberg
- Controlled Human Infections Center, Leiden University Medical Center, Leiden, Netherlands
| | - Andrew C Steer
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia
| | - Joshua Osowicki
- Tropical Diseases Research Group, Murdoch Children's Research Institute, Melbourne, VIC, Australia; Department of Paediatrics, The University of Melbourne, Parkville, VIC, Australia; Infectious Diseases Unit, Department of General Medicine, Royal Children's Hospital Melbourne, Parkville, VIC, Australia
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Batool R, Yousafzai MT, Qureshi S, Muhammad S, Qazi I, Sadaf T, Ashorn P, Qamar FN. Parental acceptance of typhoid conjugate vaccine for children aged 6 months to 15 years in an outbreak setting of Lyari Town Karachi, Pakistan. Vaccine 2023; 41:5376-5382. [PMID: 37463829 PMCID: PMC10448379 DOI: 10.1016/j.vaccine.2023.07.003] [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: 04/04/2023] [Revised: 05/18/2023] [Accepted: 07/02/2023] [Indexed: 07/20/2023]
Abstract
BACKGROUND This study aimed to evaluate the parental acceptance of Typhoid Conjugate Vaccine (TCV) and to determine the predictors of TCV vaccination status among children in an outbreak setting of extensively drug resistant (XDR) typhoid fever in Karachi, Pakistan. METHODS A cross-sectional survey using the WHO recommended rapid vaccine coverage assessment technique was conducted. Out of 11, four union councils (UCs) in Lyari Town were randomly selected. A parent or primary caretaker from the eligible household was interviewed. Data were collected using a locally validated vaccine attitudes scale (VAS). Sum of scores was calculated for VAS. A higher score denoted negative attitudes and perceptions regarding TCV and vice versa. Multivariable logistic regression was performed to determine the predictors of TCV vaccination status. RESULTS Based on the 14-item parental VAS, 78.0 % of the parents had a score between 0 to <40 and 22 % had a score ≥40. VAS score of <40 was significantly associated with higher odds of receiving TCV during the campaign setting (adjusted Odds Ratio (aOR): 1.30; 95 % Confidence Interval (CI): 1.02, 1.66). The odds of receiving TCV vaccination were higher among children whose parents were aware of the ongoing vaccination campaign in the area (aOR: 4.57; 95 % CI: 2.93, 7.12) and expressed willingness to get their child vaccinated against typhoid fever (aOR: 2.54; 95 % CI: 1.82, 3.55). CONCLUSION Parental awareness of the ongoing vaccination campaign, positive perception and attitudes towards vaccine were found to be significantly associated with TCV vaccination among children. Appropriately structured pre-vaccination awareness campaigns focused on childhood vaccination targeted towards parents are necessary to improve parental awareness, attitude and behavior towards vaccination.
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Affiliation(s)
- Rabab Batool
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Stadium Rd, PO Box 3500 Karachi 74800, Pakistan; Centre for Child, Adolescent, and Maternal Health Research, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Tampere 33520, Finland
| | - Mohammad Tahir Yousafzai
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Stadium Rd, PO Box 3500 Karachi 74800, Pakistan; The Kirby Institute, UNSW Sydney, Wallace Wurth Building High Street, UNSW Sydney, Kensington, NSW 2052, Australia
| | - Sonia Qureshi
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Stadium Rd, PO Box 3500 Karachi 74800, Pakistan
| | - Sajid Muhammad
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Stadium Rd, PO Box 3500 Karachi 74800, Pakistan
| | - Ibtisam Qazi
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Stadium Rd, PO Box 3500 Karachi 74800, Pakistan
| | - Tahira Sadaf
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Stadium Rd, PO Box 3500 Karachi 74800, Pakistan
| | - Per Ashorn
- Centre for Child, Adolescent, and Maternal Health Research, Faculty of Medicine and Health Technology, Tampere University, Arvo Ylpön katu 34, Tampere 33520, Finland
| | - Farah Naz Qamar
- Department of Pediatrics and Child Health, Aga Khan University Hospital, Stadium Rd, PO Box 3500 Karachi 74800, Pakistan.
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Khalid K, Poh CL. The Promising Potential of Reverse Vaccinology-Based Next-Generation Vaccine Development over Conventional Vaccines against Antibiotic-Resistant Bacteria. Vaccines (Basel) 2023; 11:1264. [PMID: 37515079 PMCID: PMC10385262 DOI: 10.3390/vaccines11071264] [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: 06/02/2023] [Revised: 07/14/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
The clinical use of antibiotics has led to the emergence of multidrug-resistant (MDR) bacteria, leading to the current antibiotic resistance crisis. To address this issue, next-generation vaccines are being developed to prevent antimicrobial resistance caused by MDR bacteria. Traditional vaccine platforms, such as inactivated vaccines (IVs) and live attenuated vaccines (LAVs), were effective in preventing bacterial infections. However, they have shown reduced efficacy against emerging antibiotic-resistant bacteria, including MDR M. tuberculosis. Additionally, the large-scale production of LAVs and IVs requires the growth of live pathogenic microorganisms. A more promising approach for the accelerated development of vaccines against antibiotic-resistant bacteria involves the use of in silico immunoinformatics techniques and reverse vaccinology. The bioinformatics approach can identify highly conserved antigenic targets capable of providing broader protection against emerging drug-resistant bacteria. Multi-epitope vaccines, such as recombinant protein-, DNA-, or mRNA-based vaccines, which incorporate several antigenic targets, offer the potential for accelerated development timelines. This review evaluates the potential of next-generation vaccine development based on the reverse vaccinology approach and highlights the development of safe and immunogenic vaccines through relevant examples from successful preclinical and clinical studies.
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Affiliation(s)
- Kanwal Khalid
- Centre for Virus and Vaccine Research, School of Medical and Life Sciences, Sunway University, Bandar Sunway, Subang Jaya 47500, Malaysia
| | - Chit Laa Poh
- Centre for Virus and Vaccine Research, School of Medical and Life Sciences, Sunway University, Bandar Sunway, Subang Jaya 47500, Malaysia
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McCann N, Emary K, Singh N, Mclean F, Camara S, Jones E, Kim YC, Liu X, Greenland M, Conlin K, Hill J, Verheul M, Robinson H, Angus B, Ramasamy MN, Levine MM, Pollard AJ. Accelerating clinical development of a live attenuated vaccine against Salmonella Paratyphi A (VASP): study protocol for an observer-participant-blind randomised control trial of a novel oral vaccine using a human challenge model of Salmonella Paratyphi A infection in healthy adult volunteers. BMJ Open 2023; 13:e068966. [PMID: 37225278 DOI: 10.1136/bmjopen-2022-068966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
Abstract
INTRODUCTION This is the first efficacy study of an oral live attenuated vaccine against Salmonella Paratyphi A using a human challenge model of paratyphoid infection. S. Paratyphi A is responsible for 3.3 million cases of enteric fever every year, with over 19 000 deaths. Although improvements to sanitation and access to clean water are vital to reduce the burden of this condition, vaccination offers a cost-effective, medium-term solution. Efficacy trials of potential S. Paratyphi vaccine candidates in the field are unlikely to be feasible given the large number of participants required. Human challenge models therefore offer a unique, cost-effective solution to test efficacy of such vaccines. METHODS AND ANALYSIS This is an observer-blind, randomised, placebo-controlled trial phase I/II of the oral live-attenuated vaccine against S. Paratyphi A, CVD 1902. Volunteers will be randomised 1:1 to receive two doses of CVD 1902 or placebo, 14 days apart. One month following second vaccination all volunteers will ingest S. Paratyphi A bacteria with a bicarbonate buffer solution. They will be reviewed daily in the following 14 days and diagnosed with paratyphoid infection if the predefined microbiological or clinical diagnostic criteria are met. All participants will be treated with antibiotics on diagnosis, or at day 14 postchallenge if not diagnosed. The vaccine efficacy will be determined by comparing the relative attack rate, that is, the proportion of those diagnosed with paratyphoid infection, in the vaccine and placebo groups. ETHICS AND DISSEMINATION Ethical approval for this study has been obtained from the Berkshire Medical Research Ethics Committee (REC ref 21/SC/0330). The results will be disseminated via publication in a peer-reviewed journal and presentation at international conferences. TRIAL REGISTRATION NUMBER ISRCTN15485902.
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Affiliation(s)
- Naina McCann
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Katherine Emary
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Nisha Singh
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Florence Mclean
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Susana Camara
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Elizabeth Jones
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Young Chan Kim
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Xinxue Liu
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Melanie Greenland
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Kerry Conlin
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Jennifer Hill
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Marije Verheul
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Hannah Robinson
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Brian Angus
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Maheshi N Ramasamy
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
| | - Myron M Levine
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Andrew J Pollard
- Department of Paediatrics, Oxford Vaccine Group, University of Oxford, Oxford, UK
- NIHR Oxford Biomedical Research Centre, Oxford, UK
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7
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Ren X, Zhang S, Luo P, Zhao J, Kuang W, Ni H, Zhou N, Dai H, Hong X, Yang X, Zha W, Lv Y. Spatial heterogeneity of socio-economic determinants of typhoid/paratyphoid fever in one province in central China from 2015 to 2019. BMC Public Health 2023; 23:927. [PMID: 37217879 DOI: 10.1186/s12889-023-15738-0] [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: 10/26/2022] [Accepted: 04/23/2023] [Indexed: 05/24/2023] Open
Abstract
BACKGROUND Typhoid fever and paratyphoid fever are one of the most criticial public health issues worldwide, especially in developing countries. The incidence of this disease may be closely related to socio-economic factors, but there is a lack of research on the spatial level of relevant determinants of typhoid fever and paratyphoid fever. METHODS In this study, we took Hunan Province in central China as an example and collected the data on typhoid and paratyphoid incidence and socio-economic factors in 2015-2019. Firstly spatial mapping was made on the disease prevalence, and again using geographical probe model to explore the critical influencing factors of typhoid and paratyphoid, finally employing MGWR model to analysis the spatial heterogeneity of these factors. RESULTS The results showed that the incidence of typhoid and paratyphoid fever was seasonal and periodic and frequently occurred in summer. In the case of total typhoid and paratyphoid fever, Yongzhou was the most popular, followed by Xiangxi Tujia and Miao Autonomous Prefecture, Huaihua and Chenzhou generally focused on the south and west. And Yueyang, Changde and Loudi had a slight increase trend year by year from 2015 to 2019. Moreover, the significant effects on the incidence of typhoid and paratyphoid fever from strong to weak were as follows: gender ratio(q = 0.4589), students in ordinary institutions of higher learning(q = 0.2040), per capita disposable income of all residents(q = 0.1777), number of foreign tourists received(q = 0.1697), per capita GDP(q = 0.1589), and the P values for these factors were less than 0.001. According to the MGWR model, gender ratio, per capita disposable income of all residents and Number of foreign tourists received had a positive effect on the incidence of typhoid and paratyphoid fever. In contrast, students in ordinary institutions of higher learning had a negative impact, and per capita GDP shows a bipolar change. CONCLUSIONS The incidence of typhoid and paratyphoid fever in Hunan Province from 2015 to 2019 was a marked seasonality, concentrated in the south and west of Hunan Province. Attention should be paid to the prevention and control of critical periods and concentrated areas. Different socio-economic factors may show other directions and degrees of action in other prefecture-level cities. To summarize, health education, entry-exit epidemic prevention and control can be strengthened. This study may be beneficial to carry out targeted, hierarchical and focused prevention and control of typhoid fever and paratyphoid fever, and provide scientific reference for related theoretical research.
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Affiliation(s)
- Xiang Ren
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Siyu Zhang
- Hunan Provincial Center for Disease Control and Prevention, Changsha, 410005, Hunan, China
| | - Piaoyi Luo
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Jin Zhao
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
- Changsha Center for Disease Control and Prevention, Changsha, 410024, Hunan, China
| | - Wentao Kuang
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Han Ni
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Nan Zhou
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Haoyun Dai
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China
| | - Xiuqin Hong
- Hunan Provincial People's Hospital, The First Affiliated Hospital of Hunan Normal University, Changsha, 410007, Hunan, China
| | - Xuewen Yang
- Changsha Center for Disease Control and Prevention, Changsha, 410024, Hunan, China
| | - Wenting Zha
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China.
| | - Yuan Lv
- Key Laboratory of Molecular Epidemiology of Hunan Province, School of Medicine, Hunan Normal University, Changsha, 410013, Hunan, China.
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Vanderslott S, Kumar S, Adu-Sarkodie Y, Qadri F, Zellweger RM. Typhoid Control in an Era of Antimicrobial Resistance: Challenges and Opportunities. Open Forum Infect Dis 2023; 10:S47-S52. [PMID: 37274528 PMCID: PMC10236512 DOI: 10.1093/ofid/ofad135] [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: 06/06/2023] Open
Abstract
Historically, typhoid control has been achieved with water and sanitation interventions. Today, in an era of rising antimicrobial resistance (AMR), two World Health Organization-prequalified vaccines are available to accelerate control in the shorter term. Meanwhile, water and sanitation interventions could be implemented in the longer term to sustainably prevent typhoid in low- and middle-income countries. This article first approaches typhoid control from a historical perspective, subsequently presents how vaccination could complement water and sanitation activities, and finally discusses the challenges and opportunities for impactful control of typhoid infection. It also addresses data blind spots and knowledge gaps to focus on for typhoid control and to ultimately progress towards elimination. This article presents a synthesis of discussions held in December 2021 during a roundtable session at the "12th International Conference on Typhoid and Other Invasive Salmonelloses".
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Affiliation(s)
- Samantha Vanderslott
- Oxford Vaccine Group, Department of Paediatrics, University of Oxford, Oxford, United Kingdom and NIHR Oxford Biomedical Research Centre, Oxford, Oxfordshire, United Kingdom
| | - Supriya Kumar
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, Washington, USA
| | - Yaw Adu-Sarkodie
- Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
| | - Raphaël M Zellweger
- Correspondence: Raphaël M. Zellweger, MSc, PhD, Epidemiology , Public Health & Impact, International Vaccine Institute, 1, Gwanak-ro, Gwanak-gu, Seoul 08826, South Korea. ()
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9
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Vij S, Thakur R, Kumari L, Suri CR, Rishi P. Potential of a novel flagellin epitope as a broad-spectrum vaccine candidate against enteric fever. Microb Pathog 2023; 174:105936. [PMID: 36494021 DOI: 10.1016/j.micpath.2022.105936] [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: 10/08/2022] [Revised: 11/24/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022]
Abstract
Relentless emergence of antibiotic resistant Salmonella strains, coupled with the drawbacks associated with currently available vaccines against enteric fever, warrants an urgent need to look for new vaccine candidates. Out of the multiple virulence factors harbored by Salmonella, flagella are regarded as one of the most important targets of innate as well as adaptive immune response. Individual Salmonella serotypes alternate between expression of two different antigenic forms encoded by fliC and fljB genes, respectively thereby employing this as a strategy to escape the host immune response. In the present study, using various immunoinformatic approaches, a flagellin epitope, present in both antigenic forms of typhoidal Salmonellae has been targeted. Following B-cell epitope and B-cell derived T-cell epitope prediction and interaction studies with major histocompatibility complexes using molecular docking, a peptide epitope was selected. Further, it was screened for its presence in majority of typhoidal serovars along with other useful attributes, in silico. Thereafter, safety studies were performed with the synthesized peptide. Subsequently, immunization studies were carried out using S. Typhi as well as S. Paratyphi A induced murine peritonitis model. Active immunization with peptide-BSA conjugate resulted in 75% and 80% mice survival following lethal challenge with S. Typhi and S. Paratyphi A respectively, along with a significant IgG antibody titer, thereby highlighting its immunogenic potential. Reduced bacterial burden in vital organs along with improved histoarchitecture and cytokine levels further substantiated the protective efficacy of the proposed candidate. Passive immunization studies with the candidate verified the protective efficacy of the generated antibodies against lethal challenge of bacteria in mice. Given the endemic nature of enteric fever and the antigenic variability observed in Salmonella serotypes, present study highlights the importance of using a vaccine candidate, which, along with generating a strong immune response, also exhibits a broad coverage against both, S. Typhi as well as S. Paratyphi A strains.
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Affiliation(s)
- Shania Vij
- Department of Microbiology, Basic Medical Sciences, Block I, South Campus, Panjab University, Chandigarh, India
| | - Reena Thakur
- Department of Microbiology, Basic Medical Sciences, Block I, South Campus, Panjab University, Chandigarh, India
| | - Laxmi Kumari
- University Institute of Pharmaceutical Sciences, Panjab University, Chandigarh, India
| | | | - Praveen Rishi
- Department of Microbiology, Basic Medical Sciences, Block I, South Campus, Panjab University, Chandigarh, India.
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10
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Khanam F, Ross AG, McMillan NAJ, Qadri F. Toward Typhoid Fever Elimination. Int J Infect Dis 2022; 119:41-43. [PMID: 35338009 DOI: 10.1016/j.ijid.2022.03.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/18/2022] [Accepted: 03/19/2022] [Indexed: 11/30/2022] Open
Abstract
Salmonella enterica serotype Typhi (S Typhi) causes typhoid fever and is responsible for an estimated 9 million cases and 110,000 deaths globally per annum. Typhoid fever is endemic in areas where water, sanitation, and hygiene (WaSH) infrastructure is poor. Serious complications develop in approximately 10%-15% of patients if left untreated, and this is driven by inadequate diagnostic methods and the high burden of antibiotic-resistant strains, complicating clinical management and ultimately prognosis. Asymptomatic chronic carriers, in addition to acutely infected patients, contribute to continued transmission through the shedding of the organism in the feces. The high morbidity and mortality of typhoid fever in low- and middle-income countries reinforce the need for an integrated control approach, which may ultimately lead to elimination of the disease in the 21st century. Here we discuss the challenges faced in pursuit of typhoid fever elimination.
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Affiliation(s)
- Farhana Khanam
- International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh.
| | - Allen G Ross
- Rural Health Research Institute, Charles Sturt University, Orange Campus, Australia
| | - Nigel A J McMillan
- Menzies Health Institute Queensland, University of Queensland, Gold Coast, Australia
| | - Firdausi Qadri
- International Centre for Diarrhoeal Disease Research, Dhaka, Bangladesh
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Kim CL, Cruz Espinoza LM, Vannice KS, Tadesse BT, Owusu-Dabo E, Rakotozandrindrainy R, Jani IV, Teferi M, Bassiahi Soura A, Lunguya O, Steele AD, Marks F. The Burden of Typhoid Fever in Sub-Saharan Africa: A Perspective. Res Rep Trop Med 2022; 13:1-9. [PMID: 35308424 PMCID: PMC8932916 DOI: 10.2147/rrtm.s282461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/12/2022] [Indexed: 11/23/2022] Open
Abstract
While typhoid fever has largely been eliminated in high-income regions which have developed modern water, sanitation, and hygiene facilities, it remains a significant public health burden resulting in morbidity and mortality among millions of individuals in resource-constrained settings. Prevention and control efforts are needed that integrate several high-impact interventions targeting facilities and infrastructure, including those addressing improvements in sanitation, access to safe water, and planned urbanization, together with parallel efforts directed at effective strategies for use of typhoid conjugate vaccines (TCV). The use of TCVs is a critical tool with the potential of having a rapid impact on typhoid fever disease burden; their introduction will also serve as an important strategy to combat evolving antimicrobial resistance to currently available typhoid fever treatments. Well-designed epidemiological surveillance studies play a critical role in establishing the need for, and monitoring the impact of, typhoid fever control and prevention strategies implemented by public health authorities. Here, we present a perspective based on a narrative review of the impact of typhoid fever on morbidity and mortality in sub-Saharan Africa and discuss ongoing surveillance activities and the role of vaccination in prevention and control efforts.
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Affiliation(s)
- Cara Lynn Kim
- International Vaccine Institute, Seoul, Republic of Korea
| | | | - Kirsten S Vannice
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Birkneh Tilahun Tadesse
- International Vaccine Institute, Seoul, Republic of Korea
- Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital Huddinge, Stockholm, Sweden
- Center for Innovative Drug Development and Therapeutic Trials for Africa, College of Health Sciences, Addis Ababa University, Addis Ababa, Ethiopia
| | - Ellis Owusu-Dabo
- School of Public Health, Kwame Nkrumah University of Science and Technology, Kumasi, Ghana
| | | | - Ilesh V Jani
- Instituto Nacional de Saúde (INS), Maputo Province, Mozambique
| | | | - Abdramane Bassiahi Soura
- Institut Supérieur des Sciences de la Population, Université Joseph Ki-Zerbo de Ouagadougou, Ouagadougou, Burkina Faso
| | - Octavie Lunguya
- Department of Microbiology, Institut National de Recherche Biomédicale, Kinshasa, Democratic Republic of the Congo
- Department of Medical Biology, University Teaching Hospital of Kinshasa, Kinshasa, Democratic Republic of the Congo
| | - A Duncan Steele
- Enteric and Diarrheal Diseases, Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - Florian Marks
- International Vaccine Institute, Seoul, Republic of Korea
- University of Antananarivo, Antananarivo, Madagascar
- Cambridge Institute of Therapeutic Immunology and Infectious Disease, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, Cambridge, UK
- Heidelberg Institute of Global Health, University of Heidelberg, Heidelberg, Germany
- Correspondence: Florian Marks, Tel +82-2-881-1133, Email
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