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Ojiako CP. Innovative health financing mechanisms: the case of Africa's unified approach to vaccine acquisition. Health Policy Plan 2024; 39:84-86. [PMID: 37971713 PMCID: PMC10775217 DOI: 10.1093/heapol/czad109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 08/21/2023] [Accepted: 11/10/2023] [Indexed: 11/19/2023] Open
Affiliation(s)
- Chiamaka P Ojiako
- The Robert F. Wagner Graduate School of Public Service, New York University, 295 Lafayette St, New York, NY 10012, USA
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2
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Mahoney R, Hotez PJ, Bottazzi ME. Global regulatory reforms to promote equitable vaccine access in the next pandemic. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0002482. [PMID: 37851688 PMCID: PMC10584090 DOI: 10.1371/journal.pgph.0002482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
There is broad consensus that the global response to the Covid-19 pandemic was inadequate, leading to unacceptable levels of avoidable morbidity and mortality. Three strategic missteps led to the lack of equitable vaccine access: The heavy reliance on commercial vaccine manufacturers in high-income countries (HICs) versus low- and middle-income countries (LMICs); the emergence of vaccine nationalism restricting and delaying the supply of vaccines to LMICs; and an inadequate support or recognition for LMIC national regulatory authorities. To avoid these inequities in a future pandemic, we focus on three successful vaccine development and technology transfer case studies-the Hepatitis B vaccine produced in South Korea in the 1980s; the Meningitis A vaccine for Africa led by Program for Appropriate Technologies in Health (PATH) and the World Health Organization (WHO) in the 2000s; and a recombinant SARS CoV-2 protein-based vaccine technology from the Texas Children's Hospital transferred to India and to Indonesia. In addition to expanding support for academic or non-profit product development partnerships, our analysis finds that an essential step is the strengthening of selected LMIC regulatory systems to become Stringent Regulatory Authorities (SRAs), together with a re-prioritization of the WHO Prequalification (PQ) system to ensure early vaccine availability in LMICs especially during pandemics. Advancing LMIC National Regulatory Authorities (NRAs) to Stringent Regulatory Authorities (SRAs) status will require substantial resources, but the benefits for future pandemic control and for health in LMIC would be immense. We call on the WHO, United Nation (UN) agencies and SRAs, to collaborate and implement a comprehensive roadmap to support LMIC regulators to achieve stringent status by 2030.
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Affiliation(s)
- Richard Mahoney
- Texas Children’s Hospital Center for Vaccine Development, Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
| | - Peter J. Hotez
- Texas Children’s Hospital Center for Vaccine Development, Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Biology, Baylor University, Waco, Texas, United States of America
- James A. Baker III Institute for Public Policy, Rice University, Houston, Texas, United States of America
- Hagler Institute for Advanced Study at Texas A&M University, College Station, Texas, United States of America
| | - Maria Elena Bottazzi
- Texas Children’s Hospital Center for Vaccine Development, Department of Pediatrics, Division of Tropical Medicine, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas, United States of America
- Department of Biology, Baylor University, Waco, Texas, United States of America
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Gairola S, Bonde P, Sharma P, Kale S, Goel S, Jadhav S. Stability of lyophilized Meningococcal A conjugate vaccine, (MenAfriVac™) at elevated temperatures to support controlled temperature chain (CTC) claim. Biologicals 2023; 83:101698. [PMID: 37562242 DOI: 10.1016/j.biologicals.2023.101698] [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: 11/01/2021] [Revised: 05/18/2023] [Accepted: 08/01/2023] [Indexed: 08/12/2023] Open
Abstract
Meningococcal A Conjugate Vaccine (MenAfriVac) is the world's first Monovalent Conjugate Vaccine against Neisseria Meningitidis serogroup A which has obtained Controlled Temperature Chain (CTC) label claim of "stable upto 40°C for 4 days prior to reconstitution" developed by Serum Institute of India Pvt. Ltd. Pune, India and the vaccine was granted permission from World health Organization. This paper elucidates and talks about the layout of various studies performed to characterize the product to declare as CTC at the time when the knowledge and mechanism to describe CTC was not fully known which in term helped to design the CTC guidelines. Product stability was assessed using clinical, consistency and regular lots released by NRA. The critical stability indicating parameters like free polysaccharide, molecular size distribution along with Potency and safety tests were carried out to support the product stability making sure it also qualifies for Vaccine Vial Monitor label claim of VVM30. An additional in use stability (reconstitution) was also performed. All studies indicated that the product remains stable at real time as well as elevated temperatures and well within the specifications approved by NRA and formed the strong basis for CTC claim which is now recommended by WHO.
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Affiliation(s)
- Sunil Gairola
- Quality Control Department of Serum Institute of India PVT. LTD, Pune, 411 028, India.
| | - Prashant Bonde
- Quality Control Department of Serum Institute of India PVT. LTD, Pune, 411 028, India
| | - Pankaj Sharma
- Quality Control Department of Serum Institute of India PVT. LTD, Pune, 411 028, India
| | - Sameer Kale
- Quality Control Department of Serum Institute of India PVT. LTD, Pune, 411 028, India
| | - Sunil Goel
- Quality Control Department of Serum Institute of India PVT. LTD, Pune, 411 028, India
| | - Suresh Jadhav
- Quality Control Department of Serum Institute of India PVT. LTD, Pune, 411 028, India
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4
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Euliano EM, Sklavounos AA, Wheeler AR, McHugh KJ. Translating diagnostics and drug delivery technologies to low-resource settings. Sci Transl Med 2022; 14:eabm1732. [PMID: 36223447 PMCID: PMC9716722 DOI: 10.1126/scitranslmed.abm1732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Diagnostics and drug delivery technologies engineered for low-resource settings aim to meet their technical design specifications using strategies that are compatible with limited equipment, infrastructure, and operator training. Despite many preclinical successes, very few of these devices have been translated to the clinic. Here, we identify factors that contribute to the clinical success of diagnostics and drug delivery systems for low-resource settings, including the need to engage key stakeholders at an early stage, and provide recommendations for the clinical translation of future medical technologies.
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Affiliation(s)
- Erin M. Euliano
- Department of Bioengineering, Rice University; Houston, Texas 77005, USA
| | - Alexandros A. Sklavounos
- Department of Chemistry, University of Toronto; Toronto, Ontario M5S 3H6, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto; Toronto, Ontario M5S 3E1, Canada
| | - Aaron R. Wheeler
- Department of Chemistry, University of Toronto; Toronto, Ontario M5S 3H6, Canada
- Donnelly Centre for Cellular and Biomolecular Research, University of Toronto; Toronto, Ontario M5S 3E1, Canada
- Institute of Biomedical Engineering, University of Toronto; Toronto, Ontario M5S 3G9, Canada
| | - Kevin J. McHugh
- Department of Bioengineering, Rice University; Houston, Texas 77005, USA
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5
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Marchi S, Dragoni F, Boccuto A, Idoko OT, Zazzi M, Sow S, Diallo A, Viviani S, Montomoli E, Vicenti I, Trombetta CM. Neutralizing activity of African lineage Zika virus immune sera towards Asian lineage. Acta Trop 2022; 237:106736. [DOI: 10.1016/j.actatropica.2022.106736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Revised: 10/27/2022] [Accepted: 10/27/2022] [Indexed: 11/27/2022]
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6
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Viviani S. Efficacy and Effectiveness of the Meningococcal Conjugate Group A Vaccine MenAfriVac ® in Preventing Recurrent Meningitis Epidemics in Sub-Saharan Africa. Vaccines (Basel) 2022; 10:vaccines10040617. [PMID: 35455366 PMCID: PMC9027557 DOI: 10.3390/vaccines10040617] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/11/2022] [Accepted: 04/13/2022] [Indexed: 02/01/2023] Open
Abstract
For more than a century, epidemic meningococcal disease mainly caused by serogroup A Neisseria meningitidis has been an important public health problem in sub-Saharan Africa. To address this problem, an affordable meningococcal serogroup A conjugate vaccine, MenAfriVac®, was developed specifically for populations in the African meningitis belt countries. MenAfriVac® was licensed based on safety and immunogenicity data for a population aged 1–29 years. In particular, the surrogate markers of clinical efficacy were considered to be the higher immunogenicity and the ability to prime immunological memory in infants and young children compared to a polysaccharide vaccine. Because of the magnitude of serogroup A meningitis epidemics and the high morbidity and mortality burden, the World Health Organization (WHO) recommended the MenAfriVac® deployment strategy, starting with mass vaccination campaigns for 1–29-year-olds to rapidly interrupt serogroup A person-to-person transmission and establish herd protection, followed by routine immunization of infants and toddlers to sustain protection and prevent epidemics. After licensure and WHO prequalification of MenAfriVac®, campaigns began in December 2010 in Burkina Faso, Mali, and Niger. By the middle of 2011, it was clear that the vaccine was highly effective in preventing serogroup A carriage and disease. Post introduction meningitis surveillance revealed that serogroup A meningococcal disease had disappeared from all age groups, suggesting that robust herd immunity had been achieved.
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Affiliation(s)
- Simonetta Viviani
- Department of Molecular and Developmental Medicine, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
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7
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Macias-Mendoza M, Montes-Robledo A, Arteta-Acosta C, Baldiris-Avila R, Coronell-Rodríguez W. Identification of the nasopharyngeal carriage of Neisseria meningitidis by 16S rRNA Gene sequencing in asymptomatic adolescents and young adults in Cartagena, Colombia (2019–2020). Braz J Infect Dis 2022; 26:102330. [PMID: 35176256 PMCID: PMC9387479 DOI: 10.1016/j.bjid.2022.102330] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 12/08/2021] [Accepted: 01/01/2022] [Indexed: 11/24/2022] Open
Abstract
The bacterium Neisseria meningitidis, a strictly human pathogen, can cause meningitis, meningococcemia, sepsis, and death; repeatedly it scause outbreaks around the world. The frequency of asymptomatic carriage is often high in adolescents and young adults, increasing the invasive meningococcal disease risk and likelihood of transmission. However, detailed analyses of meningococcal carriage in this population in Colombia, particularly in coastal areas, are lacking. In this study, the prevalence and characteristics of Neisseria meningitidis carriage were evaluated in asymptomatic adolescents and young adults (11-25 years old) in Cartagena, Colombia. Oropharynx samples were collected from participants between August and December 2019. The phenotypic identification of bacteria was performed by conventional methods and biochemical testing. Molecular identification to the species level was performed by 16S rRNA gene sequencing. In total, 12 of 648 samples were positive for Neisseria meningitidis by 16S rRNA sequencing, indicating a prevalence of 1.9%. Isolates were classified into four invasive serogroups (A, B, C, and W) by a comparative sequence analysis of the ribosomal gene. Despite the occurrence of meningococcal disease in Cartagena city in the last several years, the frequency of oropharyngeal carriage in adolescents and young adults was low. Serogroup A had not been previously reported in nasopharyngeal samples in Colombia. This is the first report of Neisseria meningitidis on the Colombian Caribbean coast based on 16S rRNA sequencing and is expected to guide the development of vaccination and follow-up strategies.
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Impact of MenAfriVac on Meningococcal A Meningitis in Cameroon: A Retrospective Study Using Case-by-Case-Based Surveillance Data from 2009 to 2015. J Trop Med 2021; 2021:4314892. [PMID: 34616456 PMCID: PMC8490062 DOI: 10.1155/2021/4314892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 09/08/2021] [Indexed: 11/17/2022] Open
Abstract
Meningococcal meningitis is a public health concern in Africa. Conjugated vaccine against serogroup A Neisseria meningitidis (MenAfriVac) was used in mass vaccination and was proved to have a good impact in the meningitis belt. There is a lack of information about the impact of this intervention in Cameroon after mass vaccination was undertaken. This study aimed at filling the gap in its unknown impact in Cameroon. A retrospective longitudinal study using biological monitoring data of case-by-case-based surveillance for meningitis was obtained from the National Reference Laboratories from 1 January 2009 to 20 September 2015. Immunization coverage data were obtained from Regional Public Health Delegations where immunizations took place. We compared the risks of vaccine serogroup occurrence before and after vaccinations and calculated the global impact using Halloran's formula. Annual cases of meningitis A decreased gradually from 92 in 2011 to 34 in 2012 and then to 1 case in 2013, and since 2014, no cases have been detected. The impact was estimated at 14.48% (p=0.41) in 2012 and then at 98.63% (p < 0.0001) after the end of vaccinations in 2013. This survey confirms the effectiveness of the MenAfriVac vaccine in Cameroon as expected by the WHO. The surveillance must be pursued and enhanced to monitor coming immunizations measures with multivalent conjugated vaccines for this changing threat.
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Litschko C, Budde I, Berger M, Fiebig T. Exploitation of Capsule Polymerases for Enzymatic Synthesis of Polysaccharide Antigens Used in Glycoconjugate Vaccines. Methods Mol Biol 2021; 2183:313-330. [PMID: 32959251 DOI: 10.1007/978-1-0716-0795-4_16] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The exploitation of recombinant enzymes for the synthesis of complex carbohydrates is getting increasing attention. Unfortunately, the analysis of the resulting products often requires advanced methods like nuclear magnetic resonance spectroscopy and mass spectrometry. Here, we use the capsule polymerases Cps4B and Cps11D from Actinobacillus pleuropneumoniae serotypes 4 and 11, respectively, as examples for the in vitro synthesis of capsule polymers similar to those used in glycoconjugate vaccine formulations. We demonstrate how substrate turnover in an enzymatic reaction can be analyzed by HPLC-based anion exchange chromatography and provide the protocol for separation and detection of UV-active polymer. Moreover, we describe how UV-inactive polymer can be separated and visualized using polyacrylamide gel electrophoresis followed by combined alcian blue-silver staining.
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Affiliation(s)
- Christa Litschko
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Insa Budde
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Monika Berger
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany.
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10
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Sundaram ME, Wolfson J, Osterholm M, Sow S, Ansah PO, Diallo A, Cusick SE. Meningococcal vaccines and protein-energy undernutrition in children in the African meningitis belt. Vaccine 2020; 38:8351-8356. [PMID: 33223309 PMCID: PMC7751252 DOI: 10.1016/j.vaccine.2020.11.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 11/02/2020] [Accepted: 11/03/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Vaccines to prevent meningococcal meningitis in the African meningitis belt include PsACWY, a polysaccharide-only vaccine; and PsA-TT, a polysaccharide-protein conjugate vaccine. Protein-energy undernutrition, a condition where children do not receive enough macro- or micronutrients, is related to increased risk of infectious diseases and poor immune function. Reduced immune function could affect vaccine immunogenicity. We investigated connections between protein-energy undernutrition and vaccine immunogenicity and antibody waning to PsACWY and PsA-TT in children in the African meningitis belt. METHODS This is a secondary analysis of data collected as part of four clinical trials testing the safety and efficacy of PsA-TT in children in Mali, Ghana, and Senegal. We identified whether anthropometric growth indices (low height-for-age, weight-for-height, or weight-for-age Z-score categories) were related to reduced vaccine-elicited antibody (measured with rabbit complement) from pre- to 1 month post-vaccination, in linear regression models. We also identified whether these growth indices were related to increased waning for vaccine-elicited antibody over time, in linear regression models. RESULTS A total of 697 children were included in our analysis, of which 350 (50.2%) were female; the mean (SD) age was 1.0 (1.1) years, and 578 (83.0%) received PsA-TT. In linear regression models, no consistent statistical relationship was seen between pre-vaccination anthropometric Z-score categories and vaccine immunogenicity, or decline in antibody over time, for either vaccine, although children with low weight-for-height had a greater decline in antibody from 1 to 6 months post-vaccination. CONCLUSIONS Our analysis did not find protein-energy undernutrition to be associated with immunogenicity or waning of PsACWY- or PsA-TT-elicited antibody in children living in the African meningitis belt. Future studies should consider measuring antibody titers at additional time points post-vaccination, and for longer periods of time, to determine if the rate of antibody waning over a period of several years is associated with protein-energy undernutrition.
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Affiliation(s)
| | - Julian Wolfson
- University of Minnesota School of Public Health, Minneapolis, MN, USA
| | - Michael Osterholm
- University of Minnesota School of Public Health, Minneapolis, MN, USA
| | - Samba Sow
- Centre pour Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | | | - Aldiouma Diallo
- UMR257, VITROME, Institut de Recherche pour le Développement, Senegal
| | - Sarah E Cusick
- Department of Pediatrics, University of Minnesota School of Medicine, Minneapolis, MN, USA
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11
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Homma A, Freire MDS, Possas C. Vaccines for neglected and emerging diseases in Brazil by 2030: the "valley of death" and opportunities for RD&I in Vaccinology 4.0. CAD SAUDE PUBLICA 2020; 36Suppl 2:e00128819. [PMID: 33111747 DOI: 10.1590/0102-311x00128819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 12/06/2019] [Indexed: 12/11/2022] Open
Abstract
We examine the implications of the very low competitiveness of the Brazilian vaccine RD&I system, which precludes the development of all the important vaccines required by the National Immunization Program (NIP), severely impacting the healthcare of the population. In a country dramatically affected by COVID-19 pandemic and by an exponential increase in emerging and neglected diseases, particularly the poor, these RD&I constraints for vaccines become crucial governance issues. Such constraints are aggravated by a global scenario of limited commercial interest from multinational companies in vaccines for neglected and emerging diseases, which are falling into a "valley of death," with only two vaccines produced in a pipeline of 240 vaccines. We stress that these constraints in the global pipeline are a window of opportunity for vaccine manufacturers in Brazil and other developing countries in the current paradigm transition towards Vaccinology 4.0. We conclude with recommendations for a new governance strategy supporting Brazilian public vaccine manufacturers in international collaborations for a sustainable national vaccine development and production plan by 2030.
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Affiliation(s)
- Akira Homma
- Instituto de Tecnologia em Imunobiológicos, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
| | - Marcos da Silva Freire
- Instituto de Tecnologia em Imunobiológicos, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
| | - Cristina Possas
- Instituto de Tecnologia em Imunobiológicos, Fundação Oswaldo Cruz, Rio de Janeiro, Brasil
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12
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Zika Virus in West Africa: A Seroepidemiological Study between 2007 and 2012. Viruses 2020; 12:v12060641. [PMID: 32545775 PMCID: PMC7354557 DOI: 10.3390/v12060641] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 06/03/2020] [Accepted: 06/11/2020] [Indexed: 11/17/2022] Open
Abstract
According to the World Health Organization, the entire African continent is at risk of a Zika outbreak. To increase data availability on the epidemiology of Zika virus circulation in Africa, we evaluated the immunity to Zika virus in a selected cohort of subjects from West Africa between 2007 and 2012. Human serum samples were collected in 2007 and in 2011/2012 from a cohort of 2-29-year-old subjects from Mali, Senegal, and The Gambia. A sample that tested positive by Zika virus IgG ELISA and by Zika virus microneutralization test was defined as positive. In 2007, the highest prevalence was 21.9%, found in Senegal among 18-29-year-old subjects. In 2011/2012, the highest prevalence, 22.7%, was found still in Senegal, but in 11-17-year-old subjects. During both study periods, the lowest prevalence was found in Mali, where few positive cases were found only in 18-29-year-old subjects. The Gambia showed an intermediate prevalence. In the three countries, prevalence was strongly associated with increasing age. This study contributes to understanding Zika virus circulation within three different ecological and demographic contexts with scarce or no data currently available. Results showed that Zika virus circulated actively in West Africa between the period 2007 and 2011/2012, but with some geographic specificity.
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13
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Sherman AC, Stephens DS. Serogroup A meningococcal conjugate vaccines: building sustainable and equitable vaccine strategies. Expert Rev Vaccines 2020; 19:455-463. [PMID: 32321332 DOI: 10.1080/14760584.2020.1760097] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
INTRODUCTION For well over 100 years, meningococcal disease due to serogroup A Neisseria meningitidis (MenA) has caused severe epidemics globally, especially in the meningitis belt of sub-Saharan Africa. AREAS COVERED The article reviews the background and identification of MenA, the global and molecular epidemiology of MenA, and the outbreaks of MenA in the African meningitis belt. The implementation (2010) of an equitable MenA polysaccharide-protein conjugate vaccine (PsA-TT, MenAfriVac) and the strategy to control MenA in sub-Saharan Africa is described. The development of a novel multi-serogroup meningococcal conjugate vaccine (NmCV-5) that includes serogroup A is highlighted. The PubMed database (1996-2019) was searched for studies relating to MenA outbreaks, vaccine, and immunization strategies; and the Neisseria PubMLST database of 1755 MenA isolates (1915-2019) was reviewed. EXPERT OPINION Using strategies from the successful MenAfriVac campaign, expanded collaborative partnerships were built to develop a novel, low-cost multivalent component meningococcal vaccine that includes MenA. This vaccine promises greater sustainability and is directed toward global control of meningococcal disease in the African meningitidis belt and beyond. The new WHO global roadmap addresses the continuing problem of bacterial meningitis, including meningococcal vaccine prevention, and provides a framework for further reducing the devastation of MenA.
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Affiliation(s)
- Amy C Sherman
- Department of Medicine, Emory University School of Medicine , Atlanta, Georgia, USA
| | - David S Stephens
- Division of Infectious Diseases, Department of Medicine Emory University School of Medicine , Atlanta, Georgia, USA
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Lockyer K, Gao F, Francis RJ, Eastwood D, Khatri B, Stebbings R, Derrick JP, Bolgiano B. Higher mass meningococcal group C-tetanus toxoid vaccines conjugated with carbodiimide correlate with greater immunogenicity. Vaccine 2020; 38:2859-2869. [PMID: 32089463 DOI: 10.1016/j.vaccine.2020.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/20/2020] [Accepted: 02/05/2020] [Indexed: 10/25/2022]
Abstract
To examine the link between meningococcal C (MenC) vaccine size and immunogenic response, a panel of MenC glycoconjugate vaccines were prepared differing in chain length, molar mass and hydrodynamic volume. The preparations consisted of different lengths of MenC polysaccharide (PS) covalently linked to monomeric purified tetanus toxoid (TT) carrier protein using the coupling reagent ethylcarbodiimide hydrochloride (EDC). Size exclusion chromatography with multi-angle light scattering (SEC-MALS) and viscometry analysis confirmed that the panel of MenC-TT conjugates spanned masses of 191,500 to 2,348,000 g/mol, and hydrodynamic radii ranging from 12.1 to 47.9 nm. The two largest conjugates were elliptical in shape, whereas the two smallest conjugates were more spherical. The larger conjugates appeared to fit a model described by multiple TTs with cross-linked PS, typical of lattice-like networks described previously for TT conjugates, while the smaller conjugates were found to fit a monomeric or dimeric TT configuration. The effect of vaccine conjugate size on immune responses was determined using a two-dose murine immunization. The two larger panel vaccine conjugates produced higher anti-MenC IgG1 and IgG2b titres after the second dose. Larger vaccine conjugate size also stimulated greater T-cell proliferative responses in an in vitro recall assay, although cytokines indicative of a T-helper response were not measurable. In conclusion, larger MenC-TT conjugates up to 2,348,000 g/mol produced by EDC chemistry correlate with greater humoral and cellular murine immune responses. These observations suggest that conjugate size can be an important modulator of immune response.
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Affiliation(s)
- Kay Lockyer
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Hertfordshire EN6 3QG, UK.
| | - Fang Gao
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Hertfordshire EN6 3QG, UK
| | - Robert J Francis
- Division of Analytical Biological Services, NIBSC, Blanche Lane, South Mimms, Hertfordshire EN6 3QG, UK
| | - David Eastwood
- Division of Biotherapeutics, NIBSC, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK
| | - Bhagwati Khatri
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Hertfordshire EN6 3QG, UK
| | - Richard Stebbings
- Division of Biotherapeutics, NIBSC, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG, UK
| | - Jeremy P Derrick
- Lydia Becker Institute of Immunology and Inflammation, School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, The University of Manchester, Oxford Road, Manchester, UK
| | - Barbara Bolgiano
- Division of Bacteriology, National Institute for Biological Standards and Control (NIBSC), Blanche Lane, South Mimms, Hertfordshire EN6 3QG, UK
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Arifin SMN, Zimmer C, Trotter C, Colombini A, Sidikou F, LaForce FM, Cohen T, Yaesoubi R. Cost-Effectiveness of Alternative Uses of Polyvalent Meningococcal Vaccines in Niger: An Agent-Based Transmission Modeling Study. Med Decis Making 2019; 39:553-567. [PMID: 31268405 PMCID: PMC6786941 DOI: 10.1177/0272989x19859899] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Background. Despite the introduction of an effective serogroup A conjugate vaccine (MenAfriVac™), sporadic epidemics of other Neisseria meningitidis serogroups remain a concern in Africa. Polyvalent meningococcal conjugate (PMC) vaccines may offer alternatives to current strategies that rely on routine infant vaccination with MenAfriVac plus, in the event of an epidemic, district-specific reactive campaigns using polyvalent meningococcal polysaccharide (PMP) vaccines. Methods. We developed an agent-based transmission model of N. meningitidis in Niger to compare the health effects and costs of current vaccination practice and 3 alternatives. Each alternative replaces MenAfriVac in the infant vaccination series with PMC and either replaces PMP with PMC for reactive campaigns or implements a one-time catch up campaign with PMC for children and young adults. Results. Over a 28-year period, replacement of MenAfriVac with PMC in the infant immunization series and of PMP in reactive campaigns would avert 63% of expected cases (95% prediction interval 49%-75%) if elimination of serogroup A is not followed by serogroup replacement. At a PMC price of $4/dose, this would cost $1412 ($81-$3510) per disability-adjusted life-year (DALY) averted. If serogroup replacement occurs, the cost-effectiveness of this strategy improves to $662 (cost-saving, $2473) per DALY averted. Sensitivity analyses accounting for incomplete laboratory confirmation suggest that a catch-up PMC campaign would also meet standard cost-effectiveness thresholds. Limitations. The assumption that polyvalent vaccines offer similar protection against all serogroups is simplifying. Conclusions. The use of PMC vaccines to replace MenAfriVac in routine infant immunization and in district-specific reactive campaigns would have important health benefits and is likely to be cost-effective in Niger. An additional PMC catch-up campaign would also be cost-effective if we account for incomplete laboratory reporting.
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Affiliation(s)
- S M Niaz Arifin
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Christoph Zimmer
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Caroline Trotter
- Department of Veterinary Medicine, University of Cambridge, Cambridge, UK
| | | | - Fati Sidikou
- Centre de Recherche Medicale et Sanitaire (CERMES), Niamey, NE, Niger
| | | | - Ted Cohen
- Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA
| | - Reza Yaesoubi
- Department of Health Policy and Management, Yale School of Public Health, New Haven, CT, USA
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Rappuoli R, Black S, Bloom DE. Vaccines and global health: In search of a sustainable model for vaccine development and delivery. Sci Transl Med 2019; 11:11/497/eaaw2888. [DOI: 10.1126/scitranslmed.aaw2888] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2018] [Accepted: 05/31/2019] [Indexed: 12/25/2022]
Abstract
Most vaccines for diseases in low- and middle-income countries fail to be developed because of weak or absent market incentives. Conquering diseases such as tuberculosis, HIV, malaria, and Ebola, as well as illnesses caused by multidrug-resistant pathogens, requires considerable investment and a new sustainable model of vaccine development involving close collaborations between public and private sectors.
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Topaz N, Caugant DA, Taha MK, Brynildsrud OB, Debech N, Hong E, Deghmane AE, Ouédraogo R, Ousmane S, Gamougame K, Njanpop-Lafourcade BM, Diarra S, Fox LM, Wang X. Phylogenetic relationships and regional spread of meningococcal strains in the meningitis belt, 2011-2016. EBioMedicine 2019; 41:488-496. [PMID: 30846392 PMCID: PMC6443582 DOI: 10.1016/j.ebiom.2019.02.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 02/15/2019] [Accepted: 02/26/2019] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Historically, the major cause of meningococcal epidemics in the meningitis belt of sub-Saharan Africa has been Neisseria meningitidis serogroup A (NmA), but the incidence has been substantially reduced since the introduction of a serogroup A conjugate vaccine starting in 2010. We performed whole-genome sequencing on isolates collected post-2010 to assess their phylogenetic relationships and inter-country transmission. METHODS A total of 716 invasive meningococcal isolates collected between 2011 and 2016 from 11 meningitis belt countries were whole-genome sequenced for molecular characterization by the three WHO Collaborating Centers for Meningitis. FINDINGS We identified three previously-reported clonal complexes (CC): CC11 (n = 434), CC181 (n = 62) and CC5 (n = 90) primarily associated with NmW, NmX, and NmA, respectively, and an emerging CC10217 (n = 126) associated with NmC. CC11 expanded throughout the meningitis belt independent of the 2000 Hajj outbreak strain, with isolates from Central African countries forming a distinct sub-lineage within this expansion. Two major sub-lineages were identified for CC181 isolates, one mainly expanding in West African countries and the other found in Chad. CC10217 isolates from the large outbreaks in Nigeria and Niger were more closely related than those from the few cases in Mali and Burkina Faso. INTERPRETATIONS Whole-genome based phylogenies revealed geographically distinct strain circulation as well as inter-country transmission events. Our results stress the importance of continued meningococcal molecular surveillance in the region, as well as the development of an affordable vaccine targeting these strains. FUND: Meningitis Research Foundation; CDC's Office of Advanced Molecular Detection; GAVI, the Vaccine Alliance.
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Affiliation(s)
- Nadav Topaz
- Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States
| | - Dominique A Caugant
- Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway; Department of Community Medicine and Global Health, Faculty of Medicine, University of Oslo, Oslo, Norway
| | - Muhamed-Kheir Taha
- Institut Pasteur, Invasive Bacterial Infections Unit and WHO collaborating Centre for meningitis, Paris, France
| | - Ola Brønstad Brynildsrud
- Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Nadia Debech
- Division for Infection Control and Environmental Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Eva Hong
- Institut Pasteur, Invasive Bacterial Infections Unit and WHO collaborating Centre for meningitis, Paris, France
| | - Ala-Eddine Deghmane
- Institut Pasteur, Invasive Bacterial Infections Unit and WHO collaborating Centre for meningitis, Paris, France
| | - Rasmata Ouédraogo
- Centre Hospitalier Universitaire Pédiatrique Charles de Gaulle, Ouagadougou 01, Burkina Faso
| | - Sani Ousmane
- Centre de Recherche Médicale et Sanitaire, CERMES, Niamey, Niger
| | | | | | - Seydou Diarra
- Institut National de Recherche en Santé Publique, Bamako 00223, Mali
| | - LeAnne M Fox
- Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States
| | - Xin Wang
- Meningitis and Vaccine Preventable Diseases Branch, Division of Bacterial Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, United States.
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18
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Diallo K, Coulibaly MD, Rebbetts LS, Harrison OB, Lucidarme J, Gamougam K, Tekletsion YK, Bugri A, Toure A, Issaka B, Dieng M, Trotter C, Collard JM, Sow SO, Wang X, Mayer LW, Borrow R, Greenwood BM, Maiden MCJ, Manigart O. Development of a PCR algorithm to detect and characterize Neisseria meningitidis carriage isolates in the African meningitis belt. PLoS One 2018; 13:e0206453. [PMID: 30517103 PMCID: PMC6281270 DOI: 10.1371/journal.pone.0206453] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 10/12/2018] [Indexed: 12/25/2022] Open
Abstract
Improved methods for the detection and characterization of carried Neisseria meningitidis isolates are needed. We evaluated a multiplex PCR algorithm for the detection of a variety of carriage strains in the meningitis belt. To further improve the sensitivity and specificity of the existing PCR assays, primers for gel-based PCR assays (sodC, H, Z) and primers/probe for real-time quantitative PCR (qPCR) assays (porA, cnl, sodC, H, E, Z) were modified or created using Primer Express software. Optimized multiplex PCR assays were tested on 247 well-characterised carriage isolates from six countries of the African meningitis belt. The PCR algorithm developed enabled the detection of N. meningitidis species using gel-based and real-time multiplex PCR targeting porA, sodC, cnl and characterization of capsule genes through sequential multiplex PCR assays for genogroups (A, W, X, then B, C, Y and finally H, E and Z). Targeting both porA and sodC genes together allowed the detection of meningococci with a sensitivity of 96% and 89% and a specificity of 78% and 67%, for qPCR and gel-based PCR respectively. The sensitivity and specificity ranges for capsular genogrouping of N. meningitidis are 67% - 100% and 98%-100% respectively for gel-based PCR and 90%-100% and 99%-100% for qPCR. We developed a PCR algorithm that allows simple, rapid and systematic detection and characterisation of most major and minor N. meningitidis capsular groups, including uncommon capsular groups (H, E, Z).
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Affiliation(s)
- Kanny Diallo
- Centre pour le Développement des Vaccins (CVD), Bamako, Mali
- University of Oxford (Department of Zoology), Oxford, United Kingdom
| | | | - Lisa S. Rebbetts
- University of Oxford (Department of Zoology), Oxford, United Kingdom
| | - Odile B. Harrison
- University of Oxford (Department of Zoology), Oxford, United Kingdom
| | - Jay Lucidarme
- Public Health England, (PHE–Vaccine Evaluation Unit), Manchester, United Kingdom
| | - Kadidja Gamougam
- Centre de Support en Santé Internationale (CSSI), Ndjamena, Chad
| | | | - Akalifa Bugri
- Navrongo Health Research Centre (NHRC), Navrongo, Ghana
| | - Aliou Toure
- Centre pour le Développement des Vaccins (CVD), Bamako, Mali
| | - Bassira Issaka
- Centre de Recherche Médicale et Sanitaire (CERMES), Niamey, Niger
| | - Marietou Dieng
- Institut de Recherche pour le Développement (IRD), Dakar, Senegal
| | - Caroline Trotter
- University of Cambridge (Disease Dynamics Unit -Department of Veterinary Medicine), Cambridge, United Kingdom
| | | | - Samba O. Sow
- Centre pour le Développement des Vaccins (CVD), Bamako, Mali
| | - Xin Wang
- Centers for Disease Control and Prevention, Division of Bacterial Diseases, Atlanta, United States of America
| | - Leonard W. Mayer
- Centers for Disease Control and Prevention, Division of Bacterial Diseases, Atlanta, United States of America
| | - Ray Borrow
- Public Health England, (PHE–Vaccine Evaluation Unit), Manchester, United Kingdom
| | - Brian M. Greenwood
- London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom
| | | | - Olivier Manigart
- London School of Hygiene and Tropical Medicine (LSHTM), London, United Kingdom
- * E-mail:
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19
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Songane M. Challenges for nationwide vaccine delivery in African countries. INTERNATIONAL JOURNAL OF HEALTH ECONOMICS AND MANAGEMENT 2018; 18:197-219. [PMID: 29047019 DOI: 10.1007/s10754-017-9229-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 10/09/2017] [Indexed: 06/07/2023]
Abstract
Vaccines are very effective in providing individual and community (herd) immunity against a range of diseases. In addition to protection against a range of diseases, vaccines also have social and economic benefits. However, for vaccines to be effective, routine immunization programmes must be undertaken regularly to ensure individual and community protection. Nonetheless, in many countries in Africa, vaccination coverage is low because governments struggle to deliver vaccines to the most remote areas, thus contributing to constant outbreaks of various vaccine-preventable diseases. African governments fail to deliver vaccines to a significant percentage of the target population due to many issues in key areas such as policy setting, programme management and financing, supply chain, global vaccine market, research and development of vaccines. This review gives an overview of the causes of these issues and what is currently being done to address them. This review will discuss the role of philanthropic organisations such as the Bill and Melinda Gates Foundation and global partnerships such as the global alliance for vaccines and immunizations in the development, purchase and delivery of vaccines.
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Affiliation(s)
- Mario Songane
- McGill Life Sciences Complex, McGill University, 3649 Promenade Sir-William-Osler, Montreal, H3G 0B1, Canada.
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20
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Litschko C, Oldrini D, Budde I, Berger M, Meens J, Gerardy-Schahn R, Berti F, Schubert M, Fiebig T. A New Family of Capsule Polymerases Generates Teichoic Acid-Like Capsule Polymers in Gram-Negative Pathogens. mBio 2018; 9:e00641-18. [PMID: 29844111 PMCID: PMC5974469 DOI: 10.1128/mbio.00641-18] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2018] [Accepted: 05/02/2018] [Indexed: 02/07/2023] Open
Abstract
Group 2 capsule polymers represent crucial virulence factors of Gram-negative pathogenic bacteria. They are synthesized by enzymes called capsule polymerases. In this report, we describe a new family of polymerases that combine glycosyltransferase and hexose- and polyol-phosphate transferase activity to generate complex poly(oligosaccharide phosphate) and poly(glycosylpolyol phosphate) polymers, the latter of which display similarity to wall teichoic acid (WTA), a cell wall component of Gram-positive bacteria. Using modeling and multiple-sequence alignment, we showed homology between the predicted polymerase domains and WTA type I biosynthesis enzymes, creating a link between Gram-negative and Gram-positive cell wall biosynthesis processes. The polymerases of the new family are highly abundant and found in a variety of capsule-expressing pathogens such as Neisseria meningitidis, Actinobacillus pleuropneumoniae, Haemophilus influenzae, Bibersteinia trehalosi, and Escherichia coli with both human and animal hosts. Five representative candidates were purified, their activities were confirmed using nuclear magnetic resonance (NMR) spectroscopy, and their predicted folds were validated by site-directed mutagenesis.IMPORTANCE Bacterial capsules play an important role in the interaction between a pathogen and the immune system of its host. During the last decade, capsule polymerases have become attractive tools for the production of capsule polymers applied as antigens in glycoconjugate vaccine formulations. Conventional production of glycoconjugate vaccines requires the cultivation of the pathogen and thus the highest biosafety standards, leading to tremendous costs. With regard to animal husbandry, where vaccines could avoid the extensive use of antibiotics, conventional production is not sufficiently cost-effective. In contrast, enzymatic synthesis of capsule polymers is pathogen-free and fast, offers high stereo- and regioselectivity, and works with high efficacy. The new capsule polymerase family described here vastly increases the toolbox of enzymes available for biotechnology purposes. Representatives are abundantly found in human pathogens but also in animal pathogens, paving the way for the exploitation of polymerases for the development of a new generation of vaccines for animal husbandry.
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Affiliation(s)
- Christa Litschko
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | | | - Insa Budde
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Monika Berger
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | - Jochen Meens
- Institute for Microbiology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Rita Gerardy-Schahn
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
| | | | - Mario Schubert
- Department of Biosciences, University of Salzburg, Salzburg, Austria
| | - Timm Fiebig
- Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany
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21
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Kulkarni PS, Jadhav SS, LaForce FM. Developmental strategy for a new Group A meningococcal conjugate vaccine (MenAfriVac R). Hum Vaccin Immunother 2018; 14:1103-1106. [PMID: 29048988 DOI: 10.1080/21645515.2017.1391434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Abstract
Until recently, periodic Group A meningococcal meningitis outbreaks were a major public health problem in the sub-Saharan Africa. In 2001, the Meningitis Vaccine Project (MVP), a partnership between the World Health Organization (WHO) and PATH, a Seattle-based NGO, and the Serum Institute of India Pvt Ltd (SIIPL) initiated discussions aimed at establishing a collaboration to develop a Group A meningococcal conjugate vaccine for this unmet medical need. Over the next 8 years the partnership made countless strategic decisions about product characteristics, raw materials, potential target populations, geographic prioritization and affordability of the vaccine to name a few. These decisions evolved into detailed plans for preclinical development, extensive field trials in Africa and India and a focused regulatory strategy specific for the Men A conjugate vaccine. Important characteristics of the process included, flexibility, transparency andeffective partnerships that included public agencies as well as private companies in Africa, Europe, the United States and India.
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22
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Ispasanie E, Micoli F, Lamelas A, Keller D, Berti F, De Riccio R, Di Benedettoi R, Rondini S, Pluschke G. Spontaneous point mutations in the capsule synthesis locus leading to structural and functional changes of the capsule in serogroup A meningococcal populations. Virulence 2018; 9:1138-1149. [PMID: 30067453 PMCID: PMC6086313 DOI: 10.1080/21505594.2018.1467710] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/13/2018] [Indexed: 01/09/2023] Open
Abstract
Whole genome sequencing analysis of 100 Neisseria meningitidis serogroup A isolates has revealed that the csaABCD-ctrABCD-ctrEF capsule polysaccharide synthesis locus represents a spontaneous point mutation hotspot. Structural and functional properties of the capsule of 11 carriage and two disease isolates with non-synonymous point mutations or stop codons in capsule synthesis genes were analyzed for their capsular polysaccharide expression, recognition by antibodies and sensitivity to bactericidal killing. Eight of eleven carriage isolates presenting capsule locus mutations expressed no or reduced amounts of capsule. One isolate with a stop codon in the O-acetyltransferase gene expressed non-O-acetylated polysaccharide, and was not recognized by anti-capsule antibodies. Capsule and O-acetylation deficient mutants were resistant to complement deposition and killing mediated by anti-capsular antibodies, but not by anti-lipopolysaccharide antibodies. Two capsule polymerase mutants, one carriage and one case isolate, showed capsule over-expression and increased resistance against bactericidal activity of both capsule- and lipopolysaccharide-specific antibodies. Meningococci have developed multiple strategies for changing capsule expression and structure, which is relevant both for colonization and virulence. Here we show that point mutations in the capsule synthesis genes substantially contribute to the repertoire of genetic mechanisms in natural populations leading to variability in capsule expression.
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Affiliation(s)
- Emma Ispasanie
- Swiss Tropical and Public Health Institute, Molecular Immunology Unit, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | - Araceli Lamelas
- Red de Estudios Moleculares Avanzados, Instituto de Ecologia, A.C., Veracruz, México
| | - Dominique Keller
- Swiss Tropical and Public Health Institute, Molecular Immunology Unit, Basel, Switzerland
- University of Basel, Basel, Switzerland
| | | | | | | | | | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, Molecular Immunology Unit, Basel, Switzerland
- University of Basel, Basel, Switzerland
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23
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Fiebig T, Litschko C, Freiberger F, Bethe A, Berger M, Gerardy-Schahn R. Efficient solid-phase synthesis of meningococcal capsular oligosaccharides enables simple and fast chemoenzymatic vaccine production. J Biol Chem 2017; 293:953-962. [PMID: 29187601 DOI: 10.1074/jbc.ra117.000488] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2017] [Revised: 11/28/2017] [Indexed: 12/22/2022] Open
Abstract
Neisseria meningitidis serogroups A and X are among the leading causes of bacterial meningitis in the African meningitis belt. Glycoconjugate vaccines, consisting of an antigenic carrier protein coupled to the capsular polysaccharide of the bacterial pathogen, are the most effective strategy for prevention of meningococcal disease. However, the distribution of effective glycoconjugate vaccines in this region is limited by the high cost of cultivating pathogens and purification of their capsular polysaccharides. Moreover, chemical approaches to synthesize oligosaccharide antigens have proven challenging. In the current study, we present a chemoenzymatic approach for generating tailored oligosaccharide fractions ready for activation and coupling to the carrier protein. In a first step, the elongation modes of recombinant capsular polymerases from Neisseria meningitidis serogroups A (CsaB) and X (CsxA) were characterized. We observed that CsaB is a distributive enzyme, and CsxA is a processive enzyme. Sequence comparison of these two stealth family proteins revealed a C-terminal extension in CsxA, which conferred processivity because of the existence of a second product-binding site. Deletion of the C-terminal domain converted CsxA into a distributive enzyme, allowing facile control of product length by adjusting the ratio of donor to acceptor sugars. Solid-phase fixation of the engineered capsular polymerases enabled rapid production of capsular polysaccharides with high yield and purity. In summary, the tools developed here provide critical steps toward reducing the cost of conjugate vaccine production, which will increase access in regions with the greatest need. Our work also facilitates efforts to study the relationship between oligosaccharide size and antigenicity.
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Affiliation(s)
- Timm Fiebig
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Christa Litschko
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Friedrich Freiberger
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Andrea Bethe
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Monika Berger
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Rita Gerardy-Schahn
- From the Institute of Clinical Biochemistry, Hannover Medical School, 30625 Hannover, Germany
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24
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Bregani ER, Conti M, Valcarenghi C. Pre-hospital oily chloramphenicol treatment in meningitis outbreaks in low resources environments. Trop Doct 2017; 47:328-331. [DOI: 10.1177/0049475517710397] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Bacterial meningitis is an important cause of death and disability in sub-Saharan Africa and, with pre-treatment in peripheral health centres, the poorest populations could avoid early death, especially if they live far from hospital. During the 2001 meningitis epidemic in south Chad, Moyen Chari sanitary district peripheral health centres were equipped with oily chloramphenicol (CAP) to administer before hospital referral in suspected cases of meningitis. Eighty-six patients treated with CAP in whom the diagnosis was definitively confirmed subsequently in hospital were compared with patients receiving CAP at hospital admission during the same period. A statistically significant reduction in lethality rate, need of second line treatment or adjunctive antibiotics, and mean hospital stay were confirmed in pre-treated patients.
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Affiliation(s)
- Enrico Rino Bregani
- MD, Emergency Medicine Division, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
- MD, Hôpital de Goundi, Association Tchadienne Communauté pour le Progrès, Chad
| | - Matilde Conti
- MD, Emergency Medicine Division, Fondazione IRCCS Ca’ Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Caterina Valcarenghi
- MD, Scuola di Specialità di Anestesia, Rianimazione, Terapia Intensiva e del Dolore, Università degli Studi di Milan, Italy
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25
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Luter N, Kumar R, Hozumi D, Lorenson T, Larsen S, Gowda B, Batson A. An updated methodology to review developing-country vaccine manufacturer viability. Vaccine 2017; 35:3897-3903. [PMID: 28602604 PMCID: PMC5593149 DOI: 10.1016/j.vaccine.2017.04.087] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Revised: 03/10/2017] [Accepted: 04/13/2017] [Indexed: 11/19/2022]
Abstract
In 1997, Milstien, Batson, and Meaney published "A Systematic Method for Evaluating the Potential Viability of Local Vaccine Producers." The paper identified characteristics of successful vaccine manufacturers and developed a viability framework to evaluate their performance. This paper revisits the original study after two decades to determine the ability of the framework to predict manufacturer success. By reconstructing much of the original dataset and conducting in-depth interviews, the authors developed informed views on the continued viability of manufacturers in low- and middle-income country markets. Considering the marked changes in the market and technology landscape since 1997, the authors find the viability framework to be predictive and a useful lens through which to evaluate manufacturer success or failure. Of particular interest is how incumbent and potentially new developing-country vaccine manufacturers enter and sustain production in competitive international markets and how they integrate (or fail to integrate) new technology into the production process. Ultimately, most manufacturers will need to meet global quality standards to be viable. As governments and donors consider investments in vaccine producers, the updated viability factors will be a useful tool in evaluating the prospects of manufacturers over the mid to long term. The paper emphasizes that while up-front investments are important, other critical factors-including investments in a national regulatory authority, manufacturer independence, and ability to adapt and adopt new technology-are necessary to ensure viability.
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Affiliation(s)
| | | | - Dai Hozumi
- Management Sciences for Health, 4301 North Fairfax Drive, Suite 400, Arlington, VA 22203, USA
| | - Tina Lorenson
- Bill & Melinda Gates Foundation, PO Box 23350, Seattle, WA 98102, USA
| | - Shannon Larsen
- Bill & Melinda Gates Foundation, PO Box 23350, Seattle, WA 98102, USA
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Mohammed I, Iliyasu G, Habib AG. Emergence and control of epidemic meningococcal meningitis in sub-Saharan Africa. Pathog Glob Health 2017; 111:1-6. [PMID: 28081671 PMCID: PMC5375607 DOI: 10.1080/20477724.2016.1274068] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
For more than a century, meningitis epidemics have regularly recurred across sub-Saharan Africa, involving 19 contiguous countries that constitute a 'meningitis belt' where historically the causative agent has been serogroup A meningococcus. Attempts to control epidemic meningococcal meningitis in Africa by vaccination with meningococcal polysaccharide (PS) vaccines have not been successful. This is largely because PS vaccines are poorly immunogenic in young children, do not induce immunological memory, and have little or no effect on the pharyngeal carriage. Meningococcal PS-protein conjugate vaccines overcome these deficiencies. Conjugate meningococcal vaccine against serotype A (MenAfriVac) was developed between 2001 and 2009 and deployed in 2010. So far, 262 million individuals have been immunized across the meningitis belt. The public health benefits of MenAfriVac have already been demonstrated by a sharp decline in reported cases of meningococcal disease in the countries where it has been introduced. However, serogroup replacement following mass meningitis vaccination has been noted, and in 2015 an epidemic with a novel strain of serogroup C was recorded in Niger and Nigeria for the first time since 1975. This has posed a serious challenge toward elimination of meningococcal meningitis epidemics in the African. For an effective control of meningococcal meningitis in the African meningitis belt, there is a need for an effective surveillance system, provision of rapid antigen detection kits as well as affordable vaccine that provides protection against the main serogroups causing meningitis in the sub-region.
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Affiliation(s)
| | - Garba Iliyasu
- Infectious Disease Unit, Department of Medicine, College of Health Science, Bayero University Kano, Kano, Nigeria
| | - Abdulrazaq Garba Habib
- Infectious Disease Unit, Department of Medicine, College of Health Science, Bayero University Kano, Kano, Nigeria
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Can we control all-cause meningococcal disease in Europe? Clin Microbiol Infect 2016; 22 Suppl 5:S103-S112. [DOI: 10.1016/j.cmi.2016.03.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 01/04/2016] [Accepted: 03/13/2016] [Indexed: 11/18/2022]
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An efficient cell free enzyme-based total synthesis of a meningococcal vaccine candidate. NPJ Vaccines 2016; 1:16017. [PMID: 29263856 PMCID: PMC5707881 DOI: 10.1038/npjvaccines.2016.17] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Revised: 07/14/2016] [Accepted: 08/03/2016] [Indexed: 11/14/2022] Open
Abstract
Invasive meningococcal disease (IMD) is a global health problem and vaccination has proven the most effective way of disease control. Neisseria meningitidis serogroup X (NmX) is an emerging threat in the African sub-Saharan meningitis belt, but no vaccine is available today. Leading vaccines against Nm are glycoconjugates, in which capsular polysaccharides isolated from large-scale pathogen cultures are conjugated to adjuvant proteins. Though safe and efficacious even in infants, high costs and biohazard associated with the production limit abundant application of glycoconjugate vaccines particularly in the most afflicted nations. An existing NmX vaccine candidate (CPSXn-CRM197) produced by established protocols from NmX capsule polysaccharide (CPSX) has been shown to elicit high bactericidal immunoglobulin G titres in mice. Here we describe the scalable in vitro synthesis of CPSXiv from chemically pure precursors by the use of recombinant NmX capsule polymerase. Application of the described coupling chemistry gives CPSXiv-CRM197, which in mouse vaccination experiments behaves identical to the benchmark CPSXn-CRM197. Excluding any biohazards, this novel process represents a paradigm shift in vaccine production and a premise towards vaccine manufacturing in emerging economies.
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Tang Y, Plikaytis BD, Preziosi MP, Borrow R. Influence of Age on Antibody Response and Persistence Following Immunization With MenAfriVac. Clin Infect Dis 2016; 61 Suppl 5:S531-9. [PMID: 26553685 PMCID: PMC4639503 DOI: 10.1093/cid/civ601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND A meningococcal group A conjugate vaccine, PsA-TT (MenAfriVac), developed through the Meningitis Vaccine Project and manufactured by the Serum Institute of India, Ltd, was tested in multiple clinical trials conducted mainly in Africa. The impact of age at which subjects were vaccinated on immune response and persistence postimmunization with PsA-TT was the main focus of the current analysis. METHODS Subjects who were vaccinated with a single dose of 10 µg of PsA-TT at 12-23 months or 22-33 months of age in study A conducted in Mali and The Gambia; at 2-10 years, 11-17 years, or 18-29 years of age in study B conducted in Mali, The Gambia, and Senegal; and at 14-18 weeks, 9-12 months, or 12-18 months of age in study C conducted in Ghana are included in the current analysis. Immunogenicity was measured by group A serum bactericidal antibody (SBA) titer with baby rabbit complement. RESULTS Significant differences in SBA titers were found among the age groups in studies B and C both 28 days and 1 year postimmunization. A significant difference in SBA titers between age groups 12-23 months and 22-33 months was only observed 1 year postimmunization in study A. Antibody titers remained at similar levels from 1 to 2 years postimmunization for subjects vaccinated at 12-23 months in study A and at 9-12 months or 12-18 months of age in study C. CONCLUSIONS Subjects immunized at different ages had different postimmunization immune responses as measured by SBA titers. Toddlers tended to have higher immune responses than infants. This pattern persisted at least 1 year postimmunization. CLINICAL TRIALS REGISTRATION ISRCTN78147026 (study A), ISRCTN87739946 (study B), and ISRCTN82484612 (study C).
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Affiliation(s)
- Yuxiao Tang
- Meningitis Vaccine Project, PATH, Seattle, Washington
| | | | - Marie-Pierre Preziosi
- Meningitis Vaccine Project, PATH, Ferney-Voltaire, France Meningitis Vaccine Project, Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Ray Borrow
- Vaccine Evaluation Unit, Public Health England, Royal Manchester Infirmary, United Kingdom
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Djingarey MH, Diomandé FVK, Barry R, Kandolo D, Shirehwa F, Lingani C, Novak RT, Tevi-Benissan C, Perea W, Preziosi MP, LaForce FM. Introduction and Rollout of a New Group A Meningococcal Conjugate Vaccine (PsA-TT) in African Meningitis Belt Countries, 2010-2014. Clin Infect Dis 2016; 61 Suppl 5:S434-41. [PMID: 26553672 PMCID: PMC4639493 DOI: 10.1093/cid/civ551] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Background. A group A meningococcal conjugate vaccine (PsA-TT) was developed specifically for the African “meningitis belt” and was prequalified by the World Health Organization (WHO) in June 2010. The vaccine was first used widely in Burkina Faso, Mali, and Niger in December 2010 with great success. The remaining 23 meningitis belt countries wished to use this new vaccine. Methods. With the help of African countries, WHO developed a prioritization scheme and used or adapted existing immunization guidelines to mount PsA-TT vaccination campaigns. Vaccine requirements were harmonized with the Serum Institute of India, Ltd. Results. Burkina Faso was the first country to fully immunize its 1- to 29-year-old population in December 2010. Over the next 4 years, vaccine coverage was extended to 217 million Africans living in 15 meningitis belt countries. Conclusions. The new group A meningococcal conjugate vaccine was well received, with country coverage rates ranging from 85% to 95%. The rollout proceeded smoothly because countries at highest risk were immunized first while attention was paid to geographic contiguity to maximize herd protection. Community participation was exemplary.
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Affiliation(s)
- Mamoudou H Djingarey
- Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso
| | | | - Rodrigue Barry
- Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso
| | - Denis Kandolo
- Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso
| | | | - Clement Lingani
- Inter-country Support Team for West Africa, World Health Organization, Ouagadougou, Burkina Faso
| | - Ryan T Novak
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Carol Tevi-Benissan
- World Health Organization, Regional Office for Africa, Brazzaville, Republic of Congo
| | | | - Marie-Pierre Preziosi
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland Department of Meningitis Vaccine Project, PATH, Ferney-Voltaire, France
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Kulkarni PS, Socquet M, Jadhav SS, Kapre SV, LaForce FM, Poonawalla CS. Challenges and Opportunities While Developing a Group A Meningococcal Conjugate Vaccine Within a Product Development Partnership: A Manufacturer's Perspective From the Serum Institute of India. Clin Infect Dis 2016; 61 Suppl 5:S483-8. [PMID: 26553678 PMCID: PMC4639485 DOI: 10.1093/cid/civ500] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Background. In 2002, the Meningitis Vaccine Project (MVP) chose the Serum Institute of India, Ltd (SIIL), as its manufacturing partner to establish a product development partnership (PDP) with the Meningitis Vaccine Project (MVP). MVP was a collaboration between PATH and the World Health Organization (WHO) to develop meningococcal conjugate vaccines for sub-Saharan Africa. Method. From the outset, SIIL recognized that a partnership with MVP carried some risk but also offered important opportunities for accessing new conjugate vaccine technology and know-how. Over 3 years, SIIL successfully accepted technology transfer for the group A meningococcal polysaccharide from SynCo Bio Partners and a conjugation method from the US Food and Drug Administration. Results. SIIL successfully scaled up production of a group A meningococcal conjugate vaccine that used SIIL tetanus toxoid as the carrier protein. Phase 1 studies began in India in 2005, followed by phase 2/3 studies in Africa and India. A regulatory dossier was submitted to the Indian authorities in April 2009 and WHO in September 2009. Export license was granted in December 2009, and WHO prequalification was obtained in June 2010. Vaccine was introduced at public scale in Burkina Faso that December. The group A meningococcal conjugate vaccine was named MenAfriVac, and is the first internationally qualified vaccine developed outside of big pharma. Conclusions. The project proved to be a sound investment for SIIL and is a concrete example of the potential for PDPs to provide needed products for resource-poor countries.
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Tapia MD, Findlow H, Idoko OT, Preziosi MP, Kulkarni PS, Enwere GC, Elie C, Parulekar V, Sow SO, Haidara FC, Diallo F, Doumbia M, Akinsola AK, Adegbola RA, Kampmann B, Chaumont J, Martellet L, Marchetti E, Viviani S, Tang Y, Plikaytis BD, LaForce FM, Carlone G, Borrow R. Antibody Persistence 1-5 Years Following Vaccination With MenAfriVac in African Children Vaccinated at 12-23 Months of Age. Clin Infect Dis 2016; 61 Suppl 5:S514-20. [PMID: 26553683 PMCID: PMC4639509 DOI: 10.1093/cid/civ672] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Background. Following mass vaccination campaigns in the African meningitis belt with group A meningococcal conjugate vaccine, MenAfriVac (PsA-TT), disease due to group A meningococci has nearly disappeared. Antibody persistence in healthy African toddlers was investigated. Methods. African children vaccinated at 12–23 months of age with PsA-TT were followed for evaluation of antibody persistence up to 5 years after primary vaccination. Antibody persistence was evaluated by measuring group A serum bactericidal antibody (SBA) with rabbit complement and by a group A–specific IgG enzyme-linked immunosorbent assay (ELISA). Results. Group A antibodies measured by SBA and ELISA were shown to decline in the year following vaccination and plateaued at levels significantly above baseline for up to 5 years following primary vaccination. Conclusions. A single dose of PsA-TT induces long-term sustained levels of group A meningococcal antibodies for up to 5 years after vaccination. Clinical Trials Registration. ISRTCN78147026.
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Affiliation(s)
- Milagritos D Tapia
- Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore
| | - Helen Findlow
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Olubukola T Idoko
- Vaccines and Immunity Theme, Medical Research Council Unit, Basse, The Gambia
| | - Marie-Pierre Preziosi
- Meningitis Vaccine Project, PATH, Ferney-Voltaire, France Meningitis Vaccine Project, Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | | | | | - Cheryl Elie
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | - Samba O Sow
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | | | - Fatoumata Diallo
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | - Moussa Doumbia
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | - Adebayo K Akinsola
- Vaccines and Immunity Theme, Medical Research Council Unit, Basse, The Gambia
| | | | - Beate Kampmann
- Vaccines and Immunity Theme, Medical Research Council Unit, Basse, The Gambia
| | - Julie Chaumont
- Meningitis Vaccine Project, PATH, Ferney-Voltaire, France
| | | | | | | | - Yuxiao Tang
- Meningitis Vaccine Project, PATH, Seattle, WA
| | | | | | - George Carlone
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | - Ray Borrow
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
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Diallo A, Sow SO, Idoko OT, Hirve S, Findlow H, Preziosi MP, Elie C, Kulkarni PS, Parulekar V, Diarra B, Cheick Haidara F, Diallo F, Tapia M, Akinsola AK, Adegbola RA, Bavdekar A, Juvekar S, Chaumont J, Martellet L, Marchetti E, LaForce MF, Plikaytis BD, Enwere GC, Tang Y, Borrow R, Carlone G, Viviani S. Antibody Persistence at 1 and 4 Years Following a Single Dose of MenAfriVac or Quadrivalent Polysaccharide Vaccine in Healthy Subjects Aged 2-29 Years. Clin Infect Dis 2016; 61 Suppl 5:S521-30. [PMID: 26553684 PMCID: PMC4639491 DOI: 10.1093/cid/civ518] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND Mass vaccination campaigns of the population aged 1-29 years with 1 dose of group A meningococcal (MenA) conjugate vaccine (PsA-TT, MenAfriVac) in African meningitis belt countries has resulted in the near-disappearance of MenA. The vaccine was tested in clinical trials in Africa and in India and found to be safe and highly immunogenic compared with the group A component of the licensed quadrivalent polysaccharide vaccine (PsACWY). Antibody persistence in Africa and in India was investigated. METHODS A total of 900 subjects aged 2-29 years were followed up for 4 years in Senegal, Mali, and The Gambia (study A). A total of 340 subjects aged 2-10 years were followed up for 1 year in India (study B). In study A, subjects were randomized in a 2:1 ratio, and in study B a 1:1 ratio to receive either PsA-TT or PsACWY. Immunogenicity was evaluated by measuring MenA serum bactericidal antibody (SBA) with rabbit complement and by a group A-specific immunoglobulin G (IgG) enzyme-linked immunosorbent assay. RESULTS In both studies, substantial SBA decay was observed at 6 months postvaccination in both vaccine groups, although more marked in the PsACWY group. At 1 year and 4 years (only for study A) postvaccination, SBA titers were relatively sustained in the PsA-TT group, whereas a slight increasing trend, more pronounced among the youngest, was observed in the participants aged <18 years in the PsACWY groups. The SBA titers were significantly higher in the PsA-TT group than in the PsACWY group at any time point, and the majority of subjects in the PsA-TT group had SBA titers ≥128 and group A-specific IgG concentrations ≥2 µg/mL at any point in time in both the African and Indian study populations. CONCLUSIONS Four years after vaccination with a single dose of PsA-TT vaccine in Africa, most subjects are considered protected from MenA disease. CLINICAL TRIALS REGISTRATION PsA-TT-003 (ISRCTN87739946); PsA-TT-003a (ISRCTN46335400).
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Affiliation(s)
- Aldiouma Diallo
- Institut de Recherche pour le Développement, Niakhar, Sénégal
| | - Samba O Sow
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | | | - Siddhivinayak Hirve
- Shirdi Sai Baba Hospital, Vadu/King Edward Memorial Hospital and Research Centre, Pune, India
| | - Helen Findlow
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Marie-Pierre Preziosi
- Meningitis Vaccine Project, PATH, Ferney-Voltaire, France Meningitis Vaccine Project, Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Cheryl Elie
- Centers for Disease Control and Prevention, Atlanta, Georgia
| | | | | | - Bou Diarra
- Institut de Recherche pour le Développement, Niakhar, Sénégal
| | | | - Fatoumata Diallo
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | - Milagritos Tapia
- Department of Pediatrics, Center for Vaccine Development, University of Maryland School of Medicine, Baltimore
| | | | | | - Ashish Bavdekar
- Shirdi Sai Baba Hospital, Vadu/King Edward Memorial Hospital and Research Centre, Pune, India
| | - Sanjay Juvekar
- Shirdi Sai Baba Hospital, Vadu/King Edward Memorial Hospital and Research Centre, Pune, India
| | - Julie Chaumont
- Meningitis Vaccine Project, PATH, Ferney-Voltaire, France
| | | | | | | | | | | | - Yuxiao Tang
- Meningitis Vaccine Project, PATH, Seattle, Washington
| | - Ray Borrow
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - George Carlone
- Centers for Disease Control and Prevention, Atlanta, Georgia
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Basta NE, Borrow R, Berthe A, Dembélé ATE, Onwuchekwa U, Townsend K, Boukary RM, Mabey L, Findlow H, Bai X, Sow SO. Population-Level Persistence of Immunity 2 Years After the PsA-TT Mass-Vaccination Campaign in Mali. Clin Infect Dis 2016; 61 Suppl 5:S547-53. [PMID: 26553687 PMCID: PMC4639504 DOI: 10.1093/cid/civ602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Background. In 2010, Africa's first preventive meningococcal mass vaccination campaign was launched using a newly developed Neisseria meningitidis group A (NmA) polysaccharide–tetanus toxoid conjugate vaccine, PsA-TT (MenAfriVac), designed specifically for the meningitis belt. Given PsA-TT's recent introduction, the duration of protection against meningococcal group A is unknown. Methods. We conducted a household-based, age-stratified seroprevalence survey in Bamako, Mali, in 2012, 2 years after the vaccination campaign targeted all 1- to 29-year-olds. Randomly selected participants who had been eligible for PsA-TT provided a blood sample and responded to a questionnaire. Sera were analyzed to assess NmA-specific serum bactericidal antibody titers using rabbit complement (rSBA) and NmA-specific immunoglobulin G (IgG) by enzyme-linked immunosorbent assay. The proportion of participants putatively protected and the age group- and sex-specific rSBA geometric mean titers (GMTs) and IgG geometric mean concentrations (GMCs) were determined. Results. Two years postvaccination, nearly all of the 800 participants (99.0%; 95% confidence interval [CI], 98.3%–99.7%) maintained NmA-specific rSBA titers ≥8, the accepted threshold for protection; 98.6% (95% CI, 97.8%–99.4%) had titers ≥128, and 89.5% (95% CI, 87.4%–91.6%) had titers ≥1024. The rSBA GMTs were significantly higher in females than in males aged <18 years at vaccination (P < .0001). NmA-specific IgG levels ≥2 µg/mL were found in 88.5% (95% CI, 86.3%–90.7%) of participants. Conclusions. Two years after PsA-TT introduction, a very high proportion of the population targeted for vaccination maintains high antibody titers against NmA. Assessing the duration of protection provided by PsA-TT is a priority for implementing evidence-based vaccination strategies. Representative, population-based seroprevalence studies complement clinical trials and provide this key evidence.
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Affiliation(s)
- Nicole E Basta
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis Fogarty International Center, National Institutes of Health, Bethesda, Maryland
| | - Ray Borrow
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Abdoulaye Berthe
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | | | - Uma Onwuchekwa
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
| | - Kelly Townsend
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Rahamatou M Boukary
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Lesley Mabey
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Helen Findlow
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Xilian Bai
- Vaccine Evaluation Unit, Public Health England, Manchester Royal Infirmary, United Kingdom
| | - Samba O Sow
- Centre pour le Développement des Vaccins, Ministère de la Santé, Bamako, Mali
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Frasch CE, Kapre SV, Lee CH, Préaud JM. Technical Development of a New Meningococcal Conjugate Vaccine. Clin Infect Dis 2016; 61 Suppl 5:S404-9. [PMID: 26553667 PMCID: PMC4639497 DOI: 10.1093/cid/civ595] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Background. Group A Neisseria meningitidis has been a major cause of bacterial meningitis in the sub-Saharan region of Africa in the meningitis belt. Neisseria meningitidis is an encapsulated pathogen, and antibodies against the capsular polysaccharide are protective. Polysaccharide–protein conjugate vaccines have proven to be highly effective against several different encapsulated bacterial pathogens. Purified polysaccharide vaccines have been used to control group A meningococcal (MenA) epidemics with minimal success. Methods. A monovalent MenA polysaccharide–tetanus toxoid conjugate was therefore developed. This vaccine was developed by scientists working with the Meningitis Vaccine Project, a partnership between PATH and the World Health Organization. Results. A high-efficiency conjugation method was developed in the Laboratory of Bacterial Polysaccharides in the Center for Biologics Evaluation and Research and transferred to the Serum Institute of India, Ltd, which then developed methods for purification of the group A polysaccharide and used its tetanus toxoid as the carrier protein to produce the now-licensed, highly effective MenAfriVac conjugate vaccine. Conclusions. Although many years of application of meningococcal polysaccharide vaccines have had minimal success in preventing meningococcal epidemics in the meningitis belt of Africa, our collaborative efforts to develop a MenA conjugate vaccine yielded a safe and highly effective vaccine.
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Affiliation(s)
- Carl E Frasch
- Frasch Biologics Consulting, Martinsburg, West Virginia
| | | | - Che-Hung Lee
- Center for Biologics Evaluation and Research, US Food and Drug Administration, Bethesda, Maryland
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Kristiansen PA, Jørgensen HJ, Caugant DA. Serogroup A meningococcal conjugate vaccines in Africa. Expert Rev Vaccines 2015; 14:1441-58. [PMID: 26358167 DOI: 10.1586/14760584.2015.1084232] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Serogroup A meningococcal epidemics have been a recurrent public health problem, especially in resource-poor countries of Africa. Recently, the administration in mass vaccination campaigns of a single dose of the monovalent meningococcal conjugate vaccine, MenAfriVac, to the 1-29 year-old population of sub-Saharan Africa has prevented epidemics of meningitis caused by serogroup A Neisseria meningitidis. This strategy has also been shown to provide herd protection of the non-vaccinated population. Development of meningococcal conjugate vaccines covering other serogroups and enhanced use of the pneumococcal and Haemophilus influenzae type b conjugate vaccines must be pursued to fully control bacterial meningitis in sub-Saharan Africa.
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Affiliation(s)
- Paul A Kristiansen
- a 1 WHO Collaborating Centre for Reference and Research on Meningococci, Norwegian Institute of Public Health, Lovisenberggata 8, 0456 Oslo, Norway
| | - Hannah J Jørgensen
- a 1 WHO Collaborating Centre for Reference and Research on Meningococci, Norwegian Institute of Public Health, Lovisenberggata 8, 0456 Oslo, Norway
| | - Dominique A Caugant
- a 1 WHO Collaborating Centre for Reference and Research on Meningococci, Norwegian Institute of Public Health, Lovisenberggata 8, 0456 Oslo, Norway.,b 2 Faculty of medicine, University of Oslo, Kirkeveien 166, 0450 Oslo, Norway
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Gasparini R, Panatto D, Bragazzi NL, Lai PL, Bechini A, Levi M, Durando P, Amicizia D. How the Knowledge of Interactions between Meningococcus and the Human Immune System Has Been Used to Prepare Effective Neisseria meningitidis Vaccines. J Immunol Res 2015; 2015:189153. [PMID: 26351643 PMCID: PMC4553322 DOI: 10.1155/2015/189153] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 06/09/2015] [Indexed: 01/17/2023] Open
Abstract
In the last decades, tremendous advancement in dissecting the mechanisms of pathogenicity of Neisseria meningitidis at a molecular level has been achieved, exploiting converging approaches of different disciplines, ranging from pathology to microbiology, immunology, and omics sciences (such as genomics and proteomics). Here, we review the molecular biology of the infectious agent and, in particular, its interactions with the immune system, focusing on both the innate and the adaptive responses. Meningococci exploit different mechanisms and complex machineries in order to subvert the immune system and to avoid being killed. Capsular polysaccharide and lipooligosaccharide glycan composition, in particular, play a major role in circumventing immune response. The understanding of these mechanisms has opened new horizons in the field of vaccinology. Nowadays different licensed meningococcal vaccines are available and used: conjugate meningococcal C vaccines, tetravalent conjugate vaccines, an affordable conjugate vaccine against the N. menigitidis serogroup A, and universal vaccines based on multiple antigens each one with a different and peculiar function against meningococcal group B strains.
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Affiliation(s)
- R. Gasparini
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Panatto
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - N. L. Bragazzi
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - P. L. Lai
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - A. Bechini
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - M. Levi
- Department of Health Sciences, University of Florence, Viale G.B. Morgagni 48, 50134 Florence, Italy
| | - P. Durando
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
| | - D. Amicizia
- Department of Health Sciences, University of Genoa, Via Pastore 1, 16132 Genoa, Italy
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Sáfadi MA, Bettinger JA, Maturana GM, Enwere G, Borrow R. Evolving meningococcal immunization strategies. Expert Rev Vaccines 2014; 14:505-17. [DOI: 10.1586/14760584.2015.979799] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Kristiansen PA, Ba AK, Ouédraogo AS, Sanou I, Ouédraogo R, Sangaré L, Diomandé F, Kandolo D, Saga IM, Misegades L, Clark TA, Préziosi MP, Caugant DA. Persistent low carriage of serogroup A Neisseria meningitidis two years after mass vaccination with the meningococcal conjugate vaccine, MenAfriVac. BMC Infect Dis 2014; 14:663. [PMID: 25472422 PMCID: PMC4267149 DOI: 10.1186/s12879-014-0663-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2014] [Accepted: 11/24/2014] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND The conjugate vaccine against serogroup A Neisseria meningitidis (NmA), MenAfriVac, is currently being introduced throughout the African meningitis belt. In repeated multicentre cross-sectional studies in Burkina Faso we demonstrated a significant effect of vaccination on NmA carriage for one year following mass vaccination in 2010. A new multicentre carriage study was performed in October-November 2012, two years after MenAfriVac mass vaccination. METHODS Oropharyngeal samples were collected and analysed for presence of N. meningitidis (Nm) from a representative selection of 1-29-year-olds in three districts in Burkina Faso using the same procedures as in previous years. Characterization of Nm isolates included serogrouping, multilocus sequence typing, and porA and fetA sequencing. A small sample of invasive isolates collected during the epidemic season of 2012 through the national surveillance system were also analysed. RESULTS From a total of 4964 oropharyngeal samples, overall meningococcal carriage prevalence was 7.86%. NmA prevalence was 0.02% (1 carrier), significantly lower (OR, 0.05, P = 0.005, 95% CI, 0.006-0.403) than pre-vaccination prevalence (0.39%). The single NmA isolate was sequence type (ST)-7, P1.20,9;F3-1, a clone last identified in Burkina Faso in 2003. Nm serogroup W (NmW) dominated with a carriage prevalence of 6.85%, representing 87.2% of the isolates. Of 161 NmW isolates characterized by molecular techniques, 94% belonged to the ST-11 clonal complex and 6% to the ST-175 complex. Nm serogroup X (NmX) was carried by 0.60% of the participants and ST-181 accounted for 97% of the NmX isolates. Carriage prevalence of serogroup Y and non-groupable Nm was 0.20% and 0.18%, respectively. Among the 20 isolates recovered from meningitis cases, NmW dominated (70%), followed by NmX (25%). ST-2859, the only ST with a serogroup A capsule found in Burkina Faso since 2004, was not found with another capsule, neither among carriage nor invasive isolates. CONCLUSIONS The significant reduction of NmA carriage still persisted two years following MenAfriVac vaccination, and no cases of NmA meningitis were recorded. High carriage prevalence of NmW ST-11 was consistent with the many cases of NmW meningitis in the epidemic season of 2012 and the high proportion of NmW ST-11 among the characterized invasive isolates.
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Affiliation(s)
- Paul A Kristiansen
- WHO Collaborating Center for Reference and Research on Meningococci, Norwegian Institute of Public Health, Oslo, Norway.
| | - Absatou Ky Ba
- Laboratoire National de Santé Public, Ouagadougou, Burkina Faso.
| | | | - Idrissa Sanou
- Centre Hospitalier Universitaire Souro Sanou, Bobo-Dioulasso, Burkina Faso.
- Centre Hospitalier Universitaire Yalgado, Ouagadougou, Burkina Faso.
| | - Rasmata Ouédraogo
- Centre Hospitalier Universitaire Pédiatrique Charles de Gaulle, Ouagadougou, Burkina Faso.
| | - Lassana Sangaré
- Centre Hospitalier Universitaire Yalgado, Ouagadougou, Burkina Faso.
| | - Fabien Diomandé
- WHO Inter Country Support Team, Ouagadougou, Burkina Faso.
- Centers for Disease Control and Prevention, Atlanta, USA.
| | - Denis Kandolo
- WHO Inter Country Support Team, Ouagadougou, Burkina Faso.
| | - Inger Marie Saga
- WHO Collaborating Center for Reference and Research on Meningococci, Norwegian Institute of Public Health, Oslo, Norway.
| | - Lara Misegades
- Centers for Disease Control and Prevention, Atlanta, USA.
| | - Thomas A Clark
- Centers for Disease Control and Prevention, Atlanta, USA.
| | - Marie-Pierre Préziosi
- Meningitis Vaccine Project, Ferney, France.
- WHO Initiative for Vaccine Research, Geneva, Switzerland.
| | - Dominique A Caugant
- WHO Collaborating Center for Reference and Research on Meningococci, Norwegian Institute of Public Health, Oslo, Norway.
- Faculty of Medicine, University of Oslo, Oslo, Norway.
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Abstract
Planning, implementing, and evaluating interventions against infectious diseases depend on the nature of the infectious disease; the availability of intervention measures; and logistical, economic, and political constraints. Infectious diseases and vaccine- or drug-based interventions can be loosely categorized by the degree to which the infectious disease and the intervention are well established. Pertussis, polio, and measles are three examples of long-known infectious diseases for which global vaccination has dramatically reduced the public health burden. Pertussis vaccination was introduced in the 1940s, polio vaccination in the 1950s, and measles vaccination in the 1960s, nearly eliminating these diseases in many places.
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Affiliation(s)
- M Elizabeth Halloran
- Center for Statistics and Quantitative Infectious Diseases, Vaccine and Infectious Disease Division, Fred Hutchinson Cancer Research Center, 1100 Fairview Avenue North, Seattle, WA 98109, USA. Department of Biostatistics, University of Washington, Seattle, WA 98105, USA.
| | - Ira M Longini
- Center for Statistics and Quantitative Infectious Diseases, Department of Biostatistics, College of Public Health and Health Professions, and College of Medicine, University of Florida, Gainesville, FL 32611, USA
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Daulaire N. HHS--supporting global immunization through policies, programs, and partnerships. Public Health Rep 2014; 129 Suppl 3:1-3. [PMID: 25100883 DOI: 10.1177/00333549141295s301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- Nils Daulaire
- Department of Health and Human Services, Washington, DC
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Pérez García-Pando C, Stanton MC, Diggle PJ, Trzaska S, Miller RL, Perlwitz JP, Baldasano JM, Cuevas E, Ceccato P, Yaka P, Thomson MC. Soil dust aerosols and wind as predictors of seasonal meningitis incidence in Niger. ENVIRONMENTAL HEALTH PERSPECTIVES 2014; 122:679-86. [PMID: 24633049 PMCID: PMC4080544 DOI: 10.1289/ehp.1306640] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Accepted: 03/12/2014] [Indexed: 05/02/2023]
Abstract
BACKGROUND Epidemics of meningococcal meningitis are concentrated in sub-Saharan Africa during the dry season, a period when the region is affected by the Harmattan, a dry and dusty northeasterly trade wind blowing from the Sahara into the Gulf of Guinea. OBJECTIVES We examined the potential of climate-based statistical forecasting models to predict seasonal incidence of meningitis in Niger at both the national and district levels. DATA AND METHODS We used time series of meningitis incidence from 1986 through 2006 for 38 districts in Niger. We tested models based on data that would be readily available in an operational framework, such as climate and dust, population, and the incidence of early cases before the onset of the meningitis season in January-May. Incidence was used as a proxy for immunological state, susceptibility, and carriage in the population. We compared a range of negative binomial generalized linear models fitted to the meningitis data. RESULTS At the national level, a model using early incidence in December and averaged November-December zonal wind provided the best fit (pseudo-R2 = 0.57), with zonal wind having the greatest impact. A model with surface dust concentration as a predictive variable performed indistinguishably well. At the district level, the best spatiotemporal model included zonal wind, dust concentration, early incidence in December, and population density (pseudo-R2 = 0.41). CONCLUSIONS We showed that wind and dust information and incidence in the early dry season predict part of the year-to-year variability of the seasonal incidence of meningitis at both national and district levels in Niger. Models of this form could provide an early-season alert that wind, dust, and other conditions are potentially conducive to an epidemic.
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The impact of pre-existing antibody on subsequent immune responses to meningococcal A-containing vaccines. Vaccine 2014; 32:4220-7. [PMID: 24863486 DOI: 10.1016/j.vaccine.2014.04.052] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2013] [Revised: 04/10/2014] [Accepted: 04/17/2014] [Indexed: 11/22/2022]
Abstract
Major epidemics of serogroup A meningococcal meningitis continue to affect the African meningitis belt. The development of an affordable conjugate vaccine against the disease became a priority for World Health Organization (WHO) in the late 1990s. Licensing of meningococcal vaccines has been based on serological correlates of protection alone, but such correlates might differ in different geographical regions. If high pre-vaccination antibody concentrations/titers impacts on the response to vaccination and possibly vaccine efficacy, is not clearly understood. We set out to define the pre-vaccination Meningococcal group A (Men A) antibody concentrations/titers in The Gambia and study their impact on the immunogenicity of Men A containing vaccines. Data from subjects originally enrolled in studies to test the safety and immunogenicity of the MenA vaccine recently developed for Africa meningococcal A polysaccharide conjugated to tetanus toxoid, MenAfriVac(®) (PsA-TT) were analyzed. Participants had been randomized to receive either the study vaccine PsA-TT or the reference quadrivalent plain polysaccharide vaccine containing meningococcal groups A, C, W, and Y, Mencevax(®) ACWY, GlaxoSmithKline (PsACWY) in a 2:1 ratio. Venous blood samples were collected before and 28 days after vaccination. Antibodies were assayed by enzyme-linked immunosorbent assay (ELISA) for geometric mean concentrations and serum bactericidal antibody (SBA) for functional antibody. The inter age group differences were compared using ANOVA and the pre and post-vaccination differences by t test. Over 80% of the ≥19 year olds had pre-vaccination antibody concentrations above putatively protective concentrations as compared to only 10% of 1-2 year olds. Ninety-five percent of those who received the study vaccine had ≥4-fold antibody responses if they had low pre-vaccination concentrations compared to 76% of those with high pre-vaccination concentrations. All subjects with low pre-vaccination titers attained ≥4-fold responses as compared to 76% with high titers where study vaccine was received. Our data confirm the presence of high pre-vaccination Men A antibody concentrations/titers within the African meningitis belt, with significantly higher concentrations in older individuals. Although all participants had significant increase in antibody levels following vaccination, the four-fold or greater response in antibody titers were significantly higher in individuals with lower pre-existing antibody titers, especially after receiving PsA-TT. This finding may have some implications for vaccination strategies adopted in the future.
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Jadhav S, Gautam M, Gairola S. Role of vaccine manufacturers in developing countries towards global healthcare by providing quality vaccines at affordable prices. Clin Microbiol Infect 2014; 20 Suppl 5:37-44. [PMID: 24476201 DOI: 10.1111/1469-0691.12568] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Vaccines represent one of the greatest achievements of science and medicine in the fight against infectious diseases. Vaccination is one of the most cost-effective public health tools to prevent infectious diseases. Significant progress has been made in expanding the coverage of vaccines globally, resulting in the prevention of more than two million deaths annually. In 2010, nearly 200 countries endorsed a shared vision to extend the benefits of vaccines to every person by 2020, known as the Decade of Vaccine Initiative (DoV). Vaccine manufacturers in developing countries, as represented by the Developing Countries Vaccine Manufacturers Network (DCVMN), make a significant contribution to DoV by supplying quality vaccines at affordable prices to the people who need them most. About 70% of the global Expanded Program on Immunization (EPI) vaccine supplies are met by DCVMN. Besides EPI vaccine supplies, DCVMN is also targeting vaccines against rotavirus, Japanese encephalitis, pneumonia, human papillomavirus, meningitis and neglected tropical diseases. This article reviews the roles and contributions of DCVMN in making the vaccines accessible and affordable to all.
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Affiliation(s)
- S Jadhav
- Serum Institute of India Limited, Pune, India
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Zipursky S, Djingarey MH, Lodjo JC, Olodo L, Tiendrebeogo S, Ronveaux O. Benefits of using vaccines out of the cold chain: delivering meningitis A vaccine in a controlled temperature chain during the mass immunization campaign in Benin. Vaccine 2014; 32:1431-5. [PMID: 24559895 PMCID: PMC5355207 DOI: 10.1016/j.vaccine.2014.01.038] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Revised: 01/09/2014] [Accepted: 01/15/2014] [Indexed: 11/22/2022]
Abstract
The first field use of MenAfriVac's new label allowed the vaccine to be kept at up to 40 °C for up to 4 days. 155,000 people were vaccinated using the CTC approach in the Meningitis A campaign in northern Benin in 2012. 98.7% of supervisors and 100% of vaccinators would prefer to conduct their next campaign using CTC. They saw CTC benefits as: more people vaccinated, no need to return to health centre every night, reduced logistic burden. Taking advantage of the flexibility offered by CTC opens the door for the implementation of new immunization strategies.
Background In October 2012, the Meningococcal A conjugate vaccine MenAfriVac was granted a label variation to allow for its use in a controlled temperature chain (CTC), at temperatures of up to 40 °C for not more than four days. This paper describes the first field use of MenAfriVac in a CTC during a campaign in Benin, December 2012, and assesses the feasibility and acceptability of the practice. Methods We implemented CTC in one selected district, Banikoara (target population of 147,207; 1–29 years of age), across 14 health facilities and 150 villages. We monitored the CTC practice using temperature indicators and daily monitoring sheets. At the end of the campaign we conducted a face-to-face survey to assess vaccinators’ and supervisors’ experience with CTC. Findings A mix of strategies were implemented in the field to maximize the benefits from CTC practice, depending on the distance from health centre to populations and the availability of a functioning refrigerator in the health centre. Coverage across Banikoara was 105.7%. Over the course of the campaign only nine out of approx. 15,000 vials were discarded due to surpassing the 4 day CTC limit and no vial was discarded because of exposure to a temperature higher than 40 °C or due to the Vaccine Vial Monitor (VVM) reaching its endpoint. Overall confidence and perceived usefulness of the CTC approach were very high among vaccinators and supervisors. Interpretation Vaccinators and supervisors see clear benefits from the CTC approach in low income settings, especially in hard-to-reach areas or where cold chain is weak. Taking advantage of the flexibility offered by CTC opens the door for the implementation of new immunization strategies to ensure all those at risk are protected.
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Affiliation(s)
| | | | | | | | | | - Olivier Ronveaux
- World Health Organization, Regional Office for Africa, Burkina Faso
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47
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Zahlanie YC, Hammadi MM, Ghanem ST, Dbaibo GS. Review of meningococcal vaccines with updates on immunization in adults. Hum Vaccin Immunother 2014; 10:995-1007. [PMID: 24500529 PMCID: PMC4896590 DOI: 10.4161/hv.27739] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2013] [Revised: 12/31/2013] [Accepted: 01/06/2014] [Indexed: 11/19/2022] Open
Abstract
Meningococcal disease is a serious and global life-threatening disease. Six serogroups (A, B, C, W-135, X, and Y) account for the majority of meningococcal disease worldwide. Meningococcal polysaccharide vaccines were introduced several decades ago and have led to the decline in the burden of disease. However, polysaccharide vaccines have several limitations, including poor immunogenicity in infants and toddlers, short-lived protection, lack of immunologic memory, negligible impact on nasopharyngeal carriage, and presence of hyporesponsiveness after repeated doses. The chemical conjugation of plain polysaccharide vaccines has the potential to overcome these drawbacks. Meningococcal conjugate vaccines include the quadrivalent vaccines (MenACWY-DT, MenACWY-CRM, and MenACWY-TT) as well as the monovalent A and C vaccines. These conjugate vaccines were shown to elicit strong immune response in adults. This review addresses the various aspects of meningococcal disease, the limitations posed by polysaccharide vaccines, the different conjugate vaccines with their immunogenicity and reactogenicity in adults, and the current recommendations in adults.
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Affiliation(s)
- Yorgo C Zahlanie
- Center for Infectious Diseases Research; Division of Pediatric Infectious Diseases; Department of Pediatrics and Adolescent Medicine; American University of Beirut Medical Center; Beirut, Lebanon
| | - Moza M Hammadi
- Center for Infectious Diseases Research; Division of Pediatric Infectious Diseases; Department of Pediatrics and Adolescent Medicine; American University of Beirut Medical Center; Beirut, Lebanon
| | - Soha T Ghanem
- Department of Pediatrics; Makassed General Hospital; Beirut, Lebanon
| | - Ghassan S Dbaibo
- Center for Infectious Diseases Research; Division of Pediatric Infectious Diseases; Department of Pediatrics and Adolescent Medicine; American University of Beirut Medical Center; Beirut, Lebanon
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48
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Anderson AS, Jansen KU, Eiden J. New frontiers in meningococcal vaccines. Expert Rev Vaccines 2014; 10:617-34. [DOI: 10.1586/erv.11.50] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Elias J. Loosening the grip of meningococcal disease in Africa. Lancet 2014; 383:6-8. [PMID: 24035221 DOI: 10.1016/s0140-6736(13)61898-x] [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] [Indexed: 11/16/2022]
Affiliation(s)
- Johannes Elias
- Institute for Hygiene and Microbiology, University of Würzburg, 97080 Würzburg, Germany.
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Enhancing the work of the Department of Health and Human Services national vaccine program in global immunization: recommendations of the National Vaccine Advisory Committee: approved by the National Vaccine Advisory Committee on September 12, 2013. Public Health Rep 2014; 129 Suppl 3:12-85. [PMID: 25100887 PMCID: PMC4121882 DOI: 10.1177/00333549141295s305] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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