1
|
Bergmann-Leitner ES, Hosie H, Trichilo J, Deriso E, Ranallo RT, Alefantis T, Savranskaya T, Grewal P, Ockenhouse CF, Venkatesan MM, Delvecchio VG, Angov E. Self-adjuvanting bacterial vectors expressing pre-erythrocytic antigens induce sterile protection against malaria. Front Immunol 2013; 4:176. [PMID: 23847617 PMCID: PMC3701146 DOI: 10.3389/fimmu.2013.00176] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2013] [Accepted: 06/18/2013] [Indexed: 11/24/2022] Open
Abstract
Genetically inactivated, Gram-negative bacteria that express malaria vaccine candidates represent a promising novel self-adjuvanting vaccine approach. Antigens expressed on particulate bacterial carriers not only target directly to antigen-presenting cells but also provide a strong danger signal thus circumventing the requirement for potent extraneous adjuvants. E. coli expressing malarial antigens resulted in the induction of either Th1 or Th2 biased responses that were dependent on both antigen and sub-cellular localization. Some of these constructs induced higher quality humoral responses compared to recombinant protein and most importantly they were able to induce sterile protection against sporozoite challenge in a murine model of malaria. In light of these encouraging results, two major Plasmodium falciparum pre-erythrocytic malaria vaccine targets, the Cell-Traversal protein for Ookinetes and Sporozoites (CelTOS) fused to the Maltose-binding protein in the periplasmic space and the Circumsporozoite Protein (CSP) fused to the Outer membrane (OM) protein A in the OM were expressed in a clinically relevant, attenuated Shigella strain (Shigella flexneri 2a). This type of live-attenuated vector has previously undergone clinical investigations as a vaccine against shigellosis. Using this novel delivery platform for malaria, we find that vaccination with the whole-organism represents an effective vaccination alternative that induces protective efficacy against sporozoite challenge. Shigella GeMI-Vax expressing malaria targets warrant further evaluation to determine their full potential as a dual disease, multivalent, self-adjuvanting vaccine system, against both shigellosis, and malaria.
Collapse
|
2
|
Shirley DAT, McArthur MA. The utility of human challenge studies in vaccine development: lessons learned from cholera. ACTA ACUST UNITED AC 2011; 2011:3-13. [PMID: 24482781 DOI: 10.2147/vdt.s23634] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Experiments in which virulent infectious organisms are administered to healthy adult volunteers with the intent to deliberately induce infection have been practiced for centuries. Many useful applications have developed from these experiments such as the provision of evidence of microbial pathogenicity and the identification of key virulence factors. Challenge studies have also played an important role in the evaluation of preliminary efficacy of potential vaccine candidates. Over the past 40 years, these experimental human challenge studies have found particular utility with regards to the development of both living and nonliving attenuated cholera vaccines. This review highlights some of the important contributions made by these challenge studies to cholera vaccine research.
Collapse
Affiliation(s)
- Debbie-Ann T Shirley
- Division of Infectious Diseases and Tropical Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Monica A McArthur
- Division of Infectious Diseases and Tropical Pediatrics, University of Maryland School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
3
|
Abstract
EDITORIAL NOTE This review is superseded by the published Cochrane Review, Saif‐Ur‐Rahman 2024 [https://doi.org/10.1002/14651858.CD014573], which considers only the oral killed vaccines because the live oral vaccines do not have World Health Organization (WHO) prequalification. Saif‐Ur‐Rahman 2024 also considered only currently available WHO pre‐qualified oral killed cholera vaccines (Dukoral, Shanchol, and Euvichol/Euvichol‐Plus). BACKGROUND Cholera is a cause of acute watery diarrhoea which can cause dehydration and death if not adequately treated. It usually occurs in epidemics, and is associated with poverty and poor sanitation. Effective, cheap, and easy to administer vaccines could help prevent epidemics. OBJECTIVES To assess the effectiveness and safety of oral cholera vaccines in preventing cases of cholera and deaths from cholera. SEARCH STRATEGY In October 2010, we searched the Cochrane Infectious Disease Group Specialized Register; Cochrane Central Register of Controlled Trials (CENTRAL); MEDLINE; EMBASE; LILACS; the metaRegister of Controlled Trials (mRCT), and the WHO International Clinical Trials Registry Platform (ICTRP) for relevant published and ongoing trials. SELECTION CRITERIA Randomized or quasi-randomized controlled trials of oral cholera vaccines in healthy adults and children. DATA COLLECTION AND ANALYSIS Each trial was assessed for eligibility and risk of bias by two authors working independently. Data was extracted by two independent reviewers and analysed using the Review Manager 5 software. Outcomes are reported as vaccine protective efficacy (VE) with 95% confidence intervals (CIs). MAIN RESULTS Seven large efficacy trials, four small artificial challenge studies, and twenty-nine safety trials contributed data to this review.Five variations of a killed whole cell vaccine have been evaluated in large scale efficacy trials (four trials, 249935 participants). The overall vaccine efficacy during the first year was 52% (95% CI 35% to 65%), and during the second year was 62% (95% CI 51% to 62%). Protective efficacy was lower in children aged less than 5 years; 38% (95% CI 20% to 53%) compared to older children and adults; 66% (95% CI 57% to 73%).One trial of a killed whole cell vaccine amongst military recruits demonstrated 86% protective efficacy (95% CI 37% to 97%) in a small epidemic occurring within 4 weeks of the 2-dose schedule (one trial, 1426 participants). Efficacy data is not available beyond two years for the currently available vaccine formulations, but based on data from older trials is unlikely to last beyond three years.The safety data available on killed whole cell vaccines have not demonstrated any clinically significant increase in adverse events compared to placebo.Only one live attenuated vaccine has reached Phase III clinical evaluation and was not effective (one trial, 67508 participants). Two new candidate live attenuated vaccines have demonstrated clinical effectiveness in small artificial challenge studies, but are still in development. AUTHORS' CONCLUSIONS The currently available oral killed whole cell vaccines can prevent 50 to 60% of cholera episodes during the first two years after the primary vaccination schedule. The impact and cost-effectiveness of adopting oral cholera vaccines into the routine vaccination schedule of endemic countries will depend on the prevalence of cholera, the frequency of epidemics, and access to basic services providing rapid rehydration therapy.
Collapse
Affiliation(s)
- David Sinclair
- International Health Group, Liverpool School of Tropical Medicine, Pembroke Place, Liverpool, UK, L3 5QA
| | | | | | | | | |
Collapse
|
4
|
Curved and spiral bacilli. Infect Dis (Lond) 2010. [DOI: 10.1016/b978-0-323-04579-7.00171-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
5
|
Freedman SB. Acute infectious pediatric gastroenteritis: beyond oral rehydration therapy. Expert Opin Pharmacother 2007; 8:1651-65. [PMID: 17685883 DOI: 10.1517/14656566.8.11.1651] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Worldwide diarrheal diseases are a leading cause of childhood morbidity and mortality. Improvements in gastroenteritis management have reduced the annual number of pediatric deaths attributable to gastroenteritis from 5 million in 1982 to 2 million over 20 years. Recent advances are likely to contribute further to a reduction in morbidity and mortality secondary to acute infectious gastroenteritis. A new generation of vaccines against rotavirus is entering into routine use. Research into antisecretory agents has demonstrated that this class of medications may play a significant role in the future management of acute infectious gastroenteritis. A significant body of literature has recently emerged supporting the use of the antiemetic agent ondansetron. In developing countries, the routine use of zinc is now recommended by many experts, while, in developed countries, the use of probiotic agents has been associated with significant benefits in acute infectious gastroenteritis. Finally, more aggressive intravenous rehydration strategies are being employed; however, at present, limited data from randomized clinical trials are available to support its routine use.
Collapse
Affiliation(s)
- Stephen B Freedman
- University of Toronto, Division of Pediatric Emergency Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada.
| |
Collapse
|
6
|
Adachi JA, Barriga J, Ericsson CD. Bacterial gut infections. Curr Opin Infect Dis 2006; 12:459-66. [PMID: 17035812 DOI: 10.1097/00001432-199910000-00008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Infections of the bowel as a result of bacterial enteropathogens are one of the most common medical problems. The use of novel molecular biology techniques and the recent development of new antimicrobial drugs and vaccines are helping us to identify, understand, treat and prevent these infections.
Collapse
Affiliation(s)
- J A Adachi
- Department of Internal Medicine, Division of Infectious Diseases, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | | | | |
Collapse
|
7
|
Detmer A, Glenting J. Live bacterial vaccines--a review and identification of potential hazards. Microb Cell Fact 2006; 5:23. [PMID: 16796731 PMCID: PMC1538998 DOI: 10.1186/1475-2859-5-23] [Citation(s) in RCA: 134] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2006] [Accepted: 06/23/2006] [Indexed: 12/20/2022] Open
Abstract
The use of live bacteria to induce an immune response to itself or to a carried vaccine component is an attractive vaccine strategy. Advantages of live bacterial vaccines include their mimicry of a natural infection, intrinsic adjuvant properties and their possibility to be administered orally. Derivatives of pathogenic and non-pathogenic food related bacteria are currently being evaluated as live vaccines. However, pathogenic bacteria demands for attenuation to weaken its virulence. The use of bacteria as vaccine delivery vehicles implies construction of recombinant strains that contain the gene cassette encoding the antigen. With the increased knowledge of mucosal immunity and the availability of genetic tools for heterologous gene expression the concept of live vaccine vehicles gains renewed interest. However, administration of live bacterial vaccines poses some risks. In addition, vaccination using recombinant bacteria results in the release of live recombinant organisms into nature. This places these vaccines in the debate on application of genetically modified organisms. In this review we give an overview of live bacterial vaccines on the market and describe the development of new live vaccines with a focus on attenuated bacteria and food-related lactic acid bacteria. Furthermore, we outline the safety concerns and identify the hazards associated with live bacterial vaccines and try to give some suggestions of what to consider during their development.
Collapse
Affiliation(s)
- Ann Detmer
- Danish Toxicology Centre, Hørsholm, Denmark
| | | |
Collapse
|
8
|
Abstract
While it is well-recognized that diarrheal diseases remain the second most frequent cause of mortality among children <60 months of age in the developing world, there is nevertheless a need to obtain more precise mortality and hospitalization burden data in populations living in the world's least developed areas. There is also a glaring need to obtain robust etiology data in relation to the different diarrheal disease clinical syndromes, including serotypes of Shigella and antigenic types of ETEC. Because of the poor uptake of the new typhoid and cholera vaccines licensed since 1985, it will be important to create reliable, long-term demand for the next generation of enteric vaccines, including new rotavirus, Shigella and ETEC vaccines. The first priority is to get individual vaccines licensed. Post-licensure, it will then be simpler to investigate the clinical acceptability, immunogenicity and effectiveness of various combinations of the individual licensed enteric vaccines. The extensive gut mucosal surface with its many sites for induction of immune responses make it likely that co-administrations will be successful. Partnerships of public and private agencies in the developing and the industrialized world will have to be forged to create a reliable demand for new enteric vaccines and to assure adequate, sustained supplies of affordable products. Systematic implementation programs will have to be created in the least developed, high burden, high mortality countries to deliver enteric vaccines and to document their impact after introduction.
Collapse
Affiliation(s)
- Myron M Levine
- Center for Vaccine Development, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
| |
Collapse
|
9
|
|
10
|
Nataro JP, Holmgren JR, Levine MM. Enteric Bacterial Vaccines: Salmonella, Shigella, Vibrio cholerae, Escherichia coli. Mucosal Immunol 2005. [DOI: 10.1016/b978-012491543-5/50052-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
11
|
Abstract
At least 2 million persons succumb annually to enteric infection, and in countless other patients, diarrheal disease aggravates malnutrition and susceptibility to other infections. Prevention of enteric illness by virtue of improved hygiene and provision of sanitation and water treatment is impractical in most developing countries, where morbidity and mortality rates are highest. For this reason, development of vaccines against the most important gastrointestinal infections remains a high priority.
Collapse
Affiliation(s)
- James P Nataro
- University of Maryland, School of Medicine, Center for Vaccine Development, 685 W. Baltimore St, Baltimore, MD 21201, USA.
| |
Collapse
|
12
|
Dennehy PH. Active immunization in the United States: developments over the past decade. Clin Microbiol Rev 2001; 14:872-908, table of contents. [PMID: 11585789 PMCID: PMC89007 DOI: 10.1128/cmr.14.4.872-908.2001] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Centers for Disease Control and Prevention has identified immunization as the most important public health advance of the 20th century. The purpose of this article is to review the changes that have taken place in active immunization in the United States over the past decade. Since 1990, new vaccines have become available to prevent five infectious diseases: varicella, rotavirus, hepatitis A, Lyme disease, and Japanese encephalitis virus infection. Improved vaccines have been developed to prevent Haemophilus influenzae type b, pneumococcus, pertussis, rabies, and typhoid infections. Immunization strategies for the prevention of hepatitis B, measles, meningococcal infections, and poliomyelitis have changed as a result of the changing epidemiology of these diseases. Combination vaccines are being developed to facilitate the delivery of multiple antigens, and improved vaccines are under development for cholera, influenza, and meningococcal disease. Major advances in molecular biology have enabled scientists to devise new approaches to the development of vaccines against diseases ranging from respiratory viral to enteric bacterial infections that continue to plague the world's population.
Collapse
Affiliation(s)
- P H Dennehy
- Division of Pediatric Infectious Diseases, Rhode Island Hospital, Providence, Rhode Island 02903, USA.
| |
Collapse
|
13
|
Abstract
Recent advances in prevention and treatment of cholera have occurred in the areas of vaccine testing, modifications of oral-rehydration solutions (ORS), and antimicrobial treatment. Oral vaccines consisting of killed whole bacterial cells (WC) with and without the B-subunit of cholera toxin (BS) were shown to be effective in large trials in Bangladesh, Peru, and Vietnam. However, the trials did not resolve whether two or three doses of vaccine are required and whether BS adds significantly to the immune protection of WC. Live, attenuated bacterial vaccines that are immunogenic and have been shown protective in human volunteer studies are candidates for future field trials. Rehydration of patients is a life- saving effort. The best ORS contains rice powder in place of glucose, and solutions with reduced osmolarity (245 mOsm/L, sodium 75 mEq/L) are as effective as standard ORS. Ciprofloxacin in a single dose is effective in adults, and erythromycin or ampicillin in multiple doses is effective in children.
Collapse
Affiliation(s)
- T Butler
- Department of Internal Medicine, Texas Tech University Health Sciences Center, 3601 4th Street STOP 9410, Lubbock, TX 79430-9410, USA.
| |
Collapse
|
14
|
Affiliation(s)
- E T Ryan
- Tropical and Geographic Medicine Center, Travelers' Advice and Immunization Center, Division of Infectious Diseases, Massachusetts General Hospital, Boston, Massachusetts 02114, USA
| | | |
Collapse
|
15
|
Abstract
The exponential growth in vaccine research over the last decade, in which many infectious diseases now appear to be amenable to prevention through immunization, is built upon three factors: first, a richer understanding of the immune response (in particular, cellular immunity), second, a greater finesse in understanding the molecular biology of pathogenicity, and third, an expanding use of genetic engineering techniques either to create micro-organisms of greatly attenuated virulence that may be used as vaccines, or to sequence, and express, potential vaccine antigens. With respect to vaccines composed of purified antigens, parallel work is underway to develop immuno-modulating agents (adjuvants) that will selectively and safely induce the necessary immune response. Finally, within this plethora of vaccine candidates, vaccinologists are devoting much effort to alternatives to immunization via injection, such as administration of a vaccine through the mucosal route (e.g., oral, intranasal, intravaginal, etc.), through the transcutaneous route, and even by expression of vaccine antigens in edible fruits and vegetables.
Collapse
|
16
|
Chiang SL, Mekalanos JJ. Construction of a Vibrio cholerae vaccine candidate using transposon delivery and FLP recombinase-mediated excision. Infect Immun 2000; 68:6391-7. [PMID: 11035750 PMCID: PMC97724 DOI: 10.1128/iai.68.11.6391-6397.2000] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2000] [Accepted: 08/11/2000] [Indexed: 11/20/2022] Open
Abstract
Recent efforts to develop a vaccine against the diarrheal disease cholera have focused on the use of live attenuated strains of the causative organism, Vibrio cholerae. The Ogawa lipopolysaccharide phenotype is expressed by many epidemic strains, and motility defects reduce the risk of reactive diarrhea in vaccine recipients. We therefore converted a motile Inaba(+) vaccine candidate, Peru-2, to a nonmotile Ogawa(+) phenotype using a mariner-based transposon carrying rfbT, the gene required for expression of the Ogawa phenotype. Analysis of 22 nonmotile Peru-2 mutants showed that two were Ogawa(+), and both of these strains had insertions in the flgE gene. It was possible to convert these strains to antibiotic sensitivity by introducing a recombinase that acts on sites flanking the antibiotic marker on the transposon. The resulting strains are competent for colonization in infant mice and may therefore be suitable as vaccine candidates for use either independently or in a combination with strains of different biotypes and serotypes.
Collapse
Affiliation(s)
- S L Chiang
- Department of Microbiology and Molecular Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA
| | | |
Collapse
|
17
|
Sathyamoorthy V, Hall RH, McCardell BA, Kothary MH, Ahn SJ, Ratnayake S. Purification and characterization of a cytotonic protein expressed In vitro by the live cholera vaccine candidate CVD 103-HgR. Infect Immun 2000; 68:6062-5. [PMID: 10992523 PMCID: PMC101575 DOI: 10.1128/iai.68.10.6062-6065.2000] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cholera vaccines developed by the deletion of CTX genes from Vibrio cholerae induce a residual reactogenicity in up to 10% of vaccinees. A novel cytotonic agent named secreted CHO cell elongating protein (S-CEP) was purified from culture supernatants of CVD 103-HgR (Levine et al., Lancet ii:467-470, 1988). Five fractionation steps yielded electrophoretically pure S-CEP with an M(r) of 79,000. A partially purified preparation caused fluid accumulation in the sealed infant mouse model. The amino terminus bore a unique sequence with strong homology to a cytotonic toxin of El Tor V. cholerae.
Collapse
Affiliation(s)
- V Sathyamoorthy
- Division of Virulence Assessment, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Washington, D.C. 20204, USA
| | | | | | | | | | | |
Collapse
|
18
|
Ryan ET, Calderwood SB. Cholera vaccines. Clin Infect Dis 2000; 31:561-5. [PMID: 10987721 DOI: 10.1086/313951] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2000] [Revised: 04/18/2000] [Indexed: 11/04/2022] Open
Abstract
Cholera causes significant morbidity and mortality worldwide. For travelers, the risk of developing cholera per month of stay in a developing country is approximately 0.001%-0.01%, and cholera may present as traveler's diarrhea. In the United States, only a poorly tolerated, marginally effective, parenterally administered, phenol-inactivated vaccine is available. Outside the United States, 2 additional vaccines are commercially available: an oral killed whole cell-cholera toxin recombinant B subunit vaccine (WC-rBS) and an oral live attenuated Vibrio cholerae vaccine (CVD 103-HgR). These oral vaccines are well tolerated. In field trials, WC-rBS provides 80%-85% protection from cholera caused by V. cholerae serogroup O1 for at least 6 months. In volunteer studies, CVD 103-HgR provides 62%-100% protection against cholera caused by V. cholerae for at least 6 months. No commercially available cholera vaccine protects against disease caused by V. cholerae serogroup O139. New cholera vaccines are being developed.
Collapse
Affiliation(s)
- E T Ryan
- Tropical and Geographic Medicine Center, Travelers' Advice and Immunization Center, Division of Infectious Diseases, Massachusetts General Hospital, Boston, MA, USA.
| | | |
Collapse
|
19
|
Affiliation(s)
- P Mastroeni
- Department of Biochemistry, Imperial College of Science, Technology and Medicine, London SW7 2AZ, UK
| | | | | | | | | |
Collapse
|