1
|
Gordon SB, Sichone S, Chirwa AE, Hazenberg P, Kafuko Z, Ferreira DM, Flynn J, Fortune S, Balasingam S, Biagini GA, McShane H, Mwandumba HC, Jambo K, Dheda K, Raj Sharma N, Robertson BD, Walker NF, Morton B. Practical considerations for a TB controlled human infection model (TB-CHIM); the case for TB-CHIM in Africa, a systematic review of the literature and report of 2 workshop discussions in UK and Malawi. Wellcome Open Res 2023; 8:71. [PMID: 37007907 PMCID: PMC10064019 DOI: 10.12688/wellcomeopenres.18767.2] [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] [Accepted: 06/07/2023] [Indexed: 06/23/2023] Open
Abstract
Background: Tuberculosis (TB) remains a major challenge in many domains including diagnosis, pathogenesis, prevention, treatment, drug resistance and long-term protection of the public health by vaccination. A controlled human infection model (CHIM) could potentially facilitate breakthroughs in each of these domains but has so far been considered impossible owing to technical and safety concerns. Methods: A systematic review of mycobacterial human challenge studies was carried out to evaluate progress to date, best possible ways forward and challenges to be overcome. We searched MEDLINE (1946 to current) and CINAHL (1984 to current) databases; and Google Scholar to search citations in selected manuscripts. The final search was conducted 3 rd February 2022. Inclusion criteria: adults ≥18 years old; administration of live mycobacteria; and interventional trials or cohort studies with immune and/or microbiological endpoints. Exclusion criteria: animal studies; studies with no primary data; no administration of live mycobacteria; retrospective cohort studies; case-series; and case-reports. Relevant tools (Cochrane Collaboration for RCTs and Newcastle-Ottawa Scale for non-randomised studies) were used to assess risk of bias and present a narrative synthesis of our findings. Results: The search identified 1,388 titles for review; of these 90 were reviewed for inclusion; and 27 were included. Of these, 15 were randomised controlled trials and 12 were prospective cohort studies. We focussed on administration route, challenge agent and dose administered for data extraction. Overall, BCG studies including fluorescent BCG show the most immediate utility, and genetically modified Mycobacteria tuberculosis is the most tantalising prospect of discovery breakthrough. Conclusions: The TB-CHIM development group met in 2019 and 2022 to consider the results of the systematic review, to hear presentations from many of the senior authors whose work had been reviewed and to consider best ways forward. This paper reports both the systematic review and the deliberations. Registration: PROSPERO ( CRD42022302785; 21 January 2022).
Collapse
Affiliation(s)
- Stephen B. Gordon
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Simon Sichone
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Anthony E. Chirwa
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | | | | | - Daniela M. Ferreira
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Oxford Vaccine Group, University of Oxford, Oxford, UK
| | - JoAnne Flynn
- Centre for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sarah Fortune
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA
| | | | | | - Helen McShane
- The Jenner Institute, University of Oxford, Oxford, UK
| | - Henry C Mwandumba
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Kondwani Jambo
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Keertan Dheda
- Faculty of Infectious and Tropical Diseases, Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
| | | | | | - Naomi F Walker
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Ben Morton
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - TB Controlled Human Infection Model Development Group
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- 1Day Africa, 1Day Sooner, Lusaka Province, Zambia
- Oxford Vaccine Group, University of Oxford, Oxford, UK
- Centre for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA
- Wellcome Trust, London, UK
- The Jenner Institute, University of Oxford, Oxford, UK
- Faculty of Infectious and Tropical Diseases, Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
- Imperial College London, London, UK
| |
Collapse
|
2
|
Gordon SB, Sichone S, Chirwa AE, Hazenberg P, Kafuko Z, Ferreira DM, Flynn J, Fortune S, Balasingam S, Biagini GA, McShane H, Mwandumba HC, Jambo K, Dheda K, Raj Sharma N, Robertson BD, Walker NF, Morton B. Practical considerations for a TB controlled human infection model (TB-CHIM); the case for TB-CHIM in Africa, a systematic review of the literature and report of 2 workshop discussions in UK and Malawi. Wellcome Open Res 2023; 8:71. [PMID: 37007907 PMCID: PMC10064019 DOI: 10.12688/wellcomeopenres.18767.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2023] [Indexed: 02/12/2023] Open
Abstract
Background: Tuberculosis (TB) remains a major challenge in many domains including diagnosis, pathogenesis, prevention, treatment, drug resistance and long-term protection of the public health by vaccination. A controlled human infection model (CHIM) could potentially facilitate breakthroughs in each of these domains but has so far been considered impossible owing to technical and safety concerns. Methods: A systematic review of mycobacterial human challenge studies was carried out to evaluate progress to date, best possible ways forward and challenges to be overcome. We searched MEDLINE (1946 to current) and CINAHL (1984 to current) databases; and Google Scholar to search citations in selected manuscripts. The final search was conducted 3 rd February 2022. Inclusion criteria: adults ≥18 years old; administration of live mycobacteria; and interventional trials or cohort studies with immune and/or microbiological endpoints. Exclusion criteria: animal studies; studies with no primary data; no administration of live mycobacteria; retrospective cohort studies; case-series; and case-reports. Relevant tools (Cochrane Collaboration for RCTs and Newcastle-Ottawa Scale for non-randomised studies) were used to assess risk of bias and present a narrative synthesis of our findings. Results: The search identified 1,388 titles for review; of these 90 were reviewed for inclusion; and 27 were included. Of these, 15 were randomised controlled trials and 12 were prospective cohort studies. We focussed on administration route, challenge agent and dose administered for data extraction. Overall, BCG studies including fluorescent BCG show the most immediate utility, and genetically modified Mycobacteria tuberculosis is the most tantalising prospect of discovery breakthrough. Conclusions: The TB-CHIM development group met in 2019 and 2022 to consider the results of the systematic review, to hear presentations from many of the senior authors whose work had been reviewed and to consider best ways forward. This paper reports both the systematic review and the deliberations. Registration: PROSPERO ( CRD42022302785; 21 January 2022).
Collapse
Affiliation(s)
- Stephen B. Gordon
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Simon Sichone
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | - Anthony E. Chirwa
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | | | | | - Daniela M. Ferreira
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- Oxford Vaccine Group, University of Oxford, Oxford, UK
| | - JoAnne Flynn
- Centre for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sarah Fortune
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA
| | | | | | - Helen McShane
- The Jenner Institute, University of Oxford, Oxford, UK
| | - Henry C Mwandumba
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Kondwani Jambo
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Keertan Dheda
- Faculty of Infectious and Tropical Diseases, Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
| | | | | | - Naomi F Walker
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - Ben Morton
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
| | - TB Controlled Human Infection Model Development Group
- Malawi Liverpool Wellcome Trust Clinical Research Programme, Blantyre, Malawi
- Liverpool School of Tropical Medicine, Liverpool, L3 5QA, UK
- 1Day Africa, 1Day Sooner, Lusaka Province, Zambia
- Oxford Vaccine Group, University of Oxford, Oxford, UK
- Centre for Vaccine Research, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Harvard T.H. Chan School of Public Health, Harvard University, Boston, Massachusetts, USA
- Wellcome Trust, London, UK
- The Jenner Institute, University of Oxford, Oxford, UK
- Faculty of Infectious and Tropical Diseases, Department of Immunology and Infection, London School of Hygiene and Tropical Medicine, London, UK
- Centre for Lung Infection and Immunity, Division of Pulmonology, Department of Medicine and UCT Lung Institute & South African MRC/UCT Centre for the Study of Antimicrobial Resistance, University of Cape Town, Cape Town, South Africa
- Imperial College London, London, UK
| |
Collapse
|
3
|
Kovačić D, Salihović A. Multi-epitope mRNA Vaccine Design that Exploits Variola Virus and Monkeypox Virus Proteins for Elicitation of Long-lasting Humoral and Cellular Protection Against Severe Disease. JOURNAL OF MEDICAL SCIENCE 2022. [DOI: 10.20883/medical.e750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Human monkeypox represents a relatively underexplored infection that has received increased attention since the reported outbreak in May 2022. Due to its clinical similarities with human smallpox, this virus represents a potentially tremendous health problem demanding further research in the context of host-pathogen interactions and vaccine development. Furthermore, the cross-continental spread of monkeypox has reaffirmed the need for devoting attention to human poxviruses in general, as they represent potential bioterrorism agents. Currently, smallpox vaccines are utilized in immunization efforts against monkeypox, an unsurprising fact considering their genomic and phenotypic similarities. Though it offers long-lasting protection against smallpox, its protective effects against human monkeypox continue to be explored, with encouraging results. Taking this into account, this works aims at utilizing in silico tools to identify potent peptide-based epitopes stemming from the variola virus and monkeypox virus proteomes, to devise a vaccine that would offer significant protection against smallpox and monkeypox. In theory, a vaccine that offers cross-protection against variola and monkeypox would also protect against related viruses, at least in severe clinical manifestation. Herein, we introduce a novel multi-epitope mRNA vaccine design that exploits these two viral proteomes to elicit long-lasting humoral and cellular immunity. Special consideration was taken in ensuring that the vaccine candidate elicits a Th1 immune response, correlated with protection against clinically severe disease for both viruses. Immune system simulations and physicochemical and safety analyses characterize our vaccine candidate as antigenically potent, safe, and overall stable. The protein product displays high binding affinity towards relevant immune receptors. Furthermore, the vaccine candidate is to elicit a protective, humoral and Th1-dominated cellular immune response that lasts over five years. Lastly, we build a case about the rapidity and convenience of circumventing the live attenuated vaccine platform using mRNA vaccine technology.
Collapse
|
4
|
Nutritional status positively impacts humoral immunity against its Mycobacterium tuberculosis, disease progression, and vaccine development. PLoS One 2020; 15:e0237062. [PMID: 32760105 PMCID: PMC7410285 DOI: 10.1371/journal.pone.0237062] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 07/20/2020] [Indexed: 11/25/2022] Open
Abstract
Nutritional status contributes to the regulation of immune responses against pathogens, and malnutrition has been considered as a risk factor for tuberculosis (TB). Mycobacterium tuberculosis (Mtb), the causative agent of TB, can modulate host lipid metabolism and induce lipid accumulation in macrophages, where the bacilli adopt a dormant phenotype. In addition, serum lipid components play dual roles in the regulation of and protection from Mtb infection. We analyzed the relationship between nutritional status and the humoral immune response in TB patients. We found that serum HDL levels are positively correlated with the serum IgA specific for Mtb antigens. Analysis of the relationship between serum nutritional parameters and clinical parameters in TB patients showed that serum albumin and CRP levels were negatively correlated before treatment. We also observed reduced serum LDL levels in TB patients following treatment. These findings may provide insight into the role of serum lipids in host immune responses against Mtb infection. Furthermore, improving the nutritional status may enhance vaccination efficacy.
Collapse
|
5
|
Bright MR, Curtis N, Messina NL. The role of antibodies in Bacille Calmette Guérin-mediated immune responses and protection against tuberculosis in humans: A systematic review. Tuberculosis (Edinb) 2020; 131:101947. [PMID: 33691988 DOI: 10.1016/j.tube.2020.101947] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 05/02/2020] [Accepted: 05/11/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND The mechanisms underlying Bacille Calmette-Guérin (BCG) vaccine's protective effects against tuberculosis (TB) are incompletely understood but are proposed to involve a predominantly cell-mediated process. However, there is increasing evidence for the involvement of antibodies in the control of Mycobacteria tuberculosis and in the immune response to BCG. METHODS We did a systematic review of studies investigating anti-BCG antibodies in individuals with active or latent TB, and in the response to BCG vaccination. RESULTS Of 1417 articles screened, 70 were relevant, comprising 52 investigating anti-BCG antibodies in TB and 18 investigating the anti-BCG antibody response to BCG-vaccination. Individuals with active TB have higher levels of anti-BCG antibodies compared with individuals with latent TB or healthy individuals. Antibodies to BCG are present after BCG vaccination. There is some evidence for the in utero transfer of maternal anti-BCG antibodies to infants. CONCLUSIONS BCG vaccination induces a humoral response. Antibodies targeted against BCG and its antigens may play a role in protection against active TB.
Collapse
Affiliation(s)
- Matthew R Bright
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
| | - Nigel Curtis
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Parkville, Victoria, Australia; Infectious Diseases Unit, Royal Children's Hospital Melbourne, Parkville, Victoria, Australia.
| | - Nicole L Messina
- Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia; Murdoch Children's Research Institute, Parkville, Victoria, Australia.
| |
Collapse
|
6
|
Tanner R, Villarreal-Ramos B, Vordermeier HM, McShane H. The Humoral Immune Response to BCG Vaccination. Front Immunol 2019; 10:1317. [PMID: 31244856 PMCID: PMC6579862 DOI: 10.3389/fimmu.2019.01317] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Accepted: 05/23/2019] [Indexed: 01/19/2023] Open
Abstract
Bacillus Calmette Guérin (BCG) is the only currently available vaccine against tuberculosis (TB), but it confers incomplete and variable protection against pulmonary TB in humans and bovine TB (bTB) in cattle. Insights into the immune response induced by BCG offer an underexploited opportunity to gain knowledge that may inform the design of a more efficacious vaccine, which is urgently needed to control these major global epidemics. Humoral immunity in TB and bTB has been neglected, but recent studies supporting a role for antibodies in protection against TB has driven a growing interest in determining their relevance to vaccine development. In this manuscript we review what is known about the humoral immune response to BCG vaccination and re-vaccination across species, including evidence for the induction of specific B cells and antibodies; and how these may relate to protection from TB or bTB. We discuss potential explanations for often conflicting findings and consider how factors such as BCG strain, manufacturing methodology and route of administration influence the humoral response. As novel vaccination strategies include BCG prime-boost regimens, the literature regarding off-target immunomodulatory effects of BCG vaccination on non-specific humoral immunity is also reviewed. Overall, reported outcomes to date are inconsistent, but indicate that humoral responses are heterogeneous and may play different roles in different species, populations, or individual hosts. Further study is warranted to determine whether a new TB vaccine could benefit from the targeting of humoral as well as cell-mediated immunity.
Collapse
Affiliation(s)
- Rachel Tanner
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Bernardo Villarreal-Ramos
- Department of Bacteriology, Animal and Plant Health Agency, Addlestone, United Kingdom
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - H. Martin Vordermeier
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Department of Bacteriology, Animal and Plant Health Agency, Addlestone, United Kingdom
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth University, Aberystwyth, United Kingdom
| | - Helen McShane
- The Jenner Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
7
|
Saleem I, Coombes AGA, Chambers MA. In Vitro Evaluation of Eudragit Matrices for Oral Delivery of BCG Vaccine to Animals. Pharmaceutics 2019; 11:pharmaceutics11060270. [PMID: 31185612 PMCID: PMC6630751 DOI: 10.3390/pharmaceutics11060270] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 06/03/2019] [Accepted: 06/04/2019] [Indexed: 12/18/2022] Open
Abstract
Bacillus Calmette–Guérin (BCG) vaccine is the only licensed vaccine against tuberculosis (TB) in humans and animals. It is most commonly administered parenterally, but oral delivery is highly advantageous for the immunisation of cattle and wildlife hosts of TB in particular. Since BCG is susceptible to inactivation in the gut, vaccine formulations were prepared from suspensions of Eudragit L100 copolymer powder and BCG in phosphate-buffered saline (PBS), containing Tween® 80, with and without the addition of mannitol or trehalose. Samples were frozen at −20 °C, freeze-dried and the lyophilised powders were compressed to produce BCG–Eudragit matrices. Production of the dried powders resulted in a reduction in BCG viability. Substantial losses in viability occurred at the initial formulation stage and at the stage of powder compaction. Data indicated that the Eudragit matrix protected BCG against simulated gastric fluid (SGF). The matrices remained intact in SGF and dissolved completely in simulated intestinal fluid (SIF) within three hours. The inclusion of mannitol or trehalose in the matrix provided additional protection to BCG during freeze-drying. Control needs to be exercised over BCG aggregation, freeze-drying and powder compaction conditions to minimise physical damage of the bacterial cell wall and maximise the viability of oral BCG vaccines prepared by dry powder compaction.
Collapse
Affiliation(s)
- Imran Saleem
- School of Pharmacy and Biomolecular Sciences, Liverpool John Moores University, Byrom Street, Liverpool L3 3AF, UK.
| | - Allan G A Coombes
- Pharmacy Australia Centre of Excellence, University of Queensland, School of Pharmacy, 20 Cornwall Street, Woolloongaba, QLD 4102, Australia.
| | - Mark A Chambers
- Department of Bacteriology, Animal and Plant Health Agency, Woodham Lane, New Haw, Addlestone, Surrey KT15 3NB, UK.
- School of Veterinary Medicine, University of Surrey, VSM Building, Daphne Jackson Rd, Guildford GU2 7AL, UK.
| |
Collapse
|
8
|
Monteiro-Maia R, de Pinho RT. Oral bacillus Calmette-Guérin vaccine against tuberculosis: why not? Mem Inst Oswaldo Cruz 2014; 109:838-45. [PMID: 25317714 PMCID: PMC4238780 DOI: 10.1590/0074-0276140091] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 06/16/2014] [Indexed: 12/31/2022] Open
Abstract
The bacillus Calmette-Guérin (BCG) vaccine is the only licensed vaccine for human use against tuberculosis (TB). Although controversy exists about its efficacy, the BCG vaccine is able to protect newborns and children against disseminated forms of TB, but fails to protect adults against active forms of TB. In the last few years, interest in the mucosal delivery route for the vaccine has been increasing owing to its increased capacity to induce protective immune responses both in the mucosal and the systemic immune compartments. Here, we show the importance of this route of vaccination in newly developed vaccines, especially for vaccines against TB.
Collapse
Affiliation(s)
| | - Rosa Teixeira de Pinho
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz-Fiocruz, Rio de
Janeiro, RJ, Brasil
| |
Collapse
|
9
|
Protective immunity induced by a recombinant BCG vaccine encoding the cyclophilin gene of Toxoplasma gondii. Vaccine 2013; 31:6065-71. [DOI: 10.1016/j.vaccine.2013.10.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 09/14/2013] [Accepted: 10/03/2013] [Indexed: 01/18/2023]
|
10
|
A Single Dose of Oral BCG Moreau Fails to Boost Systemic IFN-γ Responses to Tuberculin in Children in the Rural Tropics: Evidence for a Barrier to Mucosal Immunization. J Trop Med 2012; 2012:132583. [PMID: 22287972 PMCID: PMC3263634 DOI: 10.1155/2012/132583] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Revised: 09/09/2011] [Accepted: 09/28/2011] [Indexed: 12/11/2022] Open
Abstract
Immune responses to oral vaccines are impaired in populations living in conditions of poverty in developing countries, and there is evidence that concurrent geohelminth infections may contribute to this effect. We vaccinated 48 children living in rural communities in Ecuador with a single oral dose of 100 mg of BCG Moreau RDJ and measured the frequencies of tuberculin-stimulated peripheral blood mononuclear cells expressing IFN-γ before and after vaccination. Vaccinated children had active ascariasis (n = 20) or had been infected but received short- (n = 13) or long-term (n = 15) repeated treatments with albendazole prior to vaccination to treat ascariasis. All children had a BCG scar from neonatal vaccination. There was no evidence of a boosting of postvaccination IFN-γ responses in any of the 3 study groups. Our data provide support for the presence of a barrier to oral vaccination among children from the rural tropics that appeared to be independent of concurrent ascariasis.
Collapse
|
11
|
Ho MM, Southern J, Kang HN, Knezevic I. WHO Informal Consultation on standardization and evaluation of BCG vaccines Geneva, Switzerland 22-23 September 2009. Vaccine 2010; 28:6945-50. [PMID: 20692219 DOI: 10.1016/j.vaccine.2010.07.086] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 07/27/2010] [Indexed: 01/10/2023]
Abstract
The current World Health Organization Requirements for BCG vaccine are in need of revision to address the diversity of sub-strains used for production, potential improvements of quality control assays for lot release, and the establishment of sub-strain specific Reference Reagents. A consultation meeting was organized to discuss issues regarding the standardization and evaluation of BCG vaccines in the forum of regulators, BCG vaccine manufacturers, developers of selected new live tuberculosis (TB) vaccines and researchers. The development of new recombinant BCG and live attenuated TB vaccines and the characterisation of different BCG sub-strains using state-of-the-art technologies were also reviewed. The objective of the meeting was to revise and update the current recommendations focused on the scope, terminology, manufacturing issues, and the incorporation of new reference reagents and new quality control tests.
Collapse
Affiliation(s)
- Mei M Ho
- Bacteriology Division, NIBSC-HPA, Blanche Lane, South Mimms, Potters Bar, Hertfordshire, EN6 3QG, UK.
| | | | | | | |
Collapse
|
12
|
Abstract
There is limited data on the human mucosal immune response to geohelminths, but extensive data from experimental animals. Geohelminth infections may modulate mucosal immunity with effects on parasite expulsion or persistence and mucosal inflammation. Geohelminths are considered to have important effects on immunity to mucosal vaccines, infectious disease susceptibility, and anti-inflammatory effects in inflammatory bowel disease and asthma. This review will discuss the findings of studies of human immunity to geohelminths and their potential effects on non-parasite mucosal immune responses. Such effects are likely to be of public health importance in middle- and low-income countries where these parasites are endemic. There is a need for human studies on the effects of geohelminth infections on mucosal immunity and the potential for anthelmintic treatment to modify these effects. Such studies are likely to provide important insights into the regulation of mucosal immunity and inflammation, and the development of more effective mucosal vaccines.
Collapse
|
13
|
Vaccination of cattle with Mycobacterium bovis BCG by a combination of systemic and oral routes. Tuberculosis (Edinb) 2008; 88:595-600. [DOI: 10.1016/j.tube.2008.01.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Revised: 01/08/2008] [Accepted: 01/16/2008] [Indexed: 11/24/2022]
|
14
|
Antas PRZ, Castello-Branco LRR. New vaccines against tuberculosis: lessons learned from BCG immunisation in Brazil. Trans R Soc Trop Med Hyg 2008; 102:628-30. [PMID: 18440575 DOI: 10.1016/j.trstmh.2008.03.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2007] [Revised: 03/13/2008] [Accepted: 03/13/2008] [Indexed: 12/19/2022] Open
Abstract
The current tuberculosis (TB) vaccine Mycobacterium bovis BCG has been employed for some 70 years in Brazil and lessons from its use should be taken in account for the development or improvement of new TB vaccines. The vast majority of the current population has been vaccinated with BCG, with the possible requirement for a booster immunisation in adulthood for TB protection. BCG Moreau strain also protects against leprosy, meningitis and extrapulmonary forms of TB. Factors related to differences in strain, dosage and BCG administering protocol have been responsible for the variable efficacy of BCG. This vaccine is clearly affected by, as yet unclear, host and/or environmental variables. In this brief review, we describe some aspects of BCG immunisation observed in Brazil that may be of importance for improving or replacing BCG.
Collapse
Affiliation(s)
- P R Z Antas
- Laboratório de Imunologia Clínica, Instituto Oswaldo Cruz, FIOCRUZ, Manguinhos, Rio de Janeiro, RJ, Brazil.
| | | |
Collapse
|