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Niyibitegeka F, Russell FM, Jit M, Carvalho N. Inequitable Distribution of Global Economic Benefits from Pneumococcal Conjugate Vaccination. Vaccines (Basel) 2024; 12:767. [PMID: 39066405 PMCID: PMC11281544 DOI: 10.3390/vaccines12070767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 06/27/2024] [Accepted: 07/04/2024] [Indexed: 07/28/2024] Open
Abstract
Many low- and middle-income countries have been slow to introduce the pneumococcal conjugate vaccine (PCV) into their routine childhood immunization schedules despite a high burden of disease. We estimated the global economic surplus of PCV, defined as the sum of the net value to 194 countries (i.e., monetized health benefits minus net costs) and to vaccine manufacturers (i.e., profits). We further explored the distribution of global economic surplus across country income groups and manufacturers and the effect of different pricing strategies based on cross-subsidization, pooled procurement, and various tiered pricing mechanisms. We found that current PCV pricing policies disproportionately benefit high-income countries and manufacturers. Based on the 2021 birth cohort, high-income countries and manufacturers combined received 76.5% of the net economic benefits generated by the vaccine. Over the two decades of PCV availability, low- and middle-income countries have not received the full economic benefits of PCV. Cross-subsidization of the vaccine price for low- and middle-income countries and pooled procurement policies that would relate the vaccine price to the value of economic benefits generated for each country could reduce these inequalities. This analysis offers important considerations that may improve the equitable introduction and use of new and under-utilized vaccines.
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Affiliation(s)
- Fulgence Niyibitegeka
- Centre for Health Policy, Melbourne School of Population and Global Health, The University of Melbourne, Carlton, VIC 3053, Australia;
| | - Fiona M. Russell
- Asia-Pacific Health, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia;
- Centre for International Child Health, Department of Paediatrics, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Mark Jit
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London WC1H 9SH, UK;
| | - Natalie Carvalho
- Centre for Health Policy, Melbourne School of Population and Global Health, The University of Melbourne, Carlton, VIC 3053, Australia;
- Asia-Pacific Health, Murdoch Children’s Research Institute, Melbourne, VIC 3052, Australia;
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Olayinka F, Sauer M, Menning L, Summers D, Wonodi C, Mackay S, MacDonald NE, Peter Figueroa J, Andriamitantsoa B, Bonsu G, Haldar P, Lindstrand A, Shimp L. Building and sustaining public and political commitment to the value of vaccination: Recommendations for the Immunization Agenda 2030 (Strategic Priority Area 2). Vaccine 2024; 42 Suppl 1:S43-S53. [PMID: 36528448 DOI: 10.1016/j.vaccine.2022.11.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 08/11/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022]
Abstract
Vaccines have contributed to substantial improvements in health and social development outcomes for millions in recent decades. However, equitable access to immunization remains a critical challenge that has stalled progress toward improving several health indicators around the world. The COVID-19 pandemic has also negatively impacted routine immunization services around the world further threatening universal access to the benefits of lifesaving vaccines. To overcome these challenges, the Immunization Agenda 2030 (IA2030) focuses on increasing both commitment and demand for vaccines. There are three broad barriers that will need to be addressed in order to achieve national and subnational immunization targets: (1) shifting leadership priorities and resource constraints, (2) visibility of disease burden, and (3) social and behavioral drivers. IA2030 proposes a set of interventions to address these barriers. First, efforts to ensure government engagement on immunization financing, regulatory, and legislative frameworks. Next, those in subnational leadership positions and local community members need to be further engaged to ensure local commitment and demand. Governance structures and health agencies must accept responsibility and be held accountable for delivering inclusive, quality, and accessible services and for achieving national targets. Further, the availability of quality immunization services and commitment to adequate financing and resourcing must go hand-in-hand with public health programs to increase access to and demand for vaccination. Last, strengthening trust in immunization systems and improving individual and program resilience can help mitigate the risk of vaccine confidence crises. These interventions together can help ensure a world where everyone, everywhere has access to and uses vaccines for lifesaving vaccination.
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Affiliation(s)
| | - Molly Sauer
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA; International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - Lisa Menning
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | | | - Chizoba Wonodi
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA; International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | | | | | | | | | - George Bonsu
- Expanded Program on Immunization, Government of Ghana, Accra, Ghana
| | - Pradeep Haldar
- Ministry of Health and Family Welfare, Government of India, New Delhi, India
| | - Ann Lindstrand
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Lora Shimp
- JSI Research & Training Institute, Inc, Arlington, USA.
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Njuma Libwea J, Ngomba VA, Taku NA, Ndongo CB, Ngono Noah BD, Fointama N, Kobela M, Huhtala H, Epee E, Koulla-Shiro S, Ndombo PK. Prevalence of prolonged otitis media with effusion among 2 to 3 years old Cameroonian children in the era of 13-valent pneumococcal conjugate vaccines. IJID REGIONS 2024; 10:240-247. [PMID: 38532743 PMCID: PMC10964058 DOI: 10.1016/j.ijregi.2023.11.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 11/08/2023] [Accepted: 11/12/2023] [Indexed: 03/28/2024]
Abstract
Objectives There is data scarcity on the overall effects of pneumococcal conjugate vaccines (PCVs) on otitis media (OM) in low- and middle-income countries. The impact of the 13-valent PCV (PCV13) program on OM was evaluated in Cameroon where infant vaccination was implemented in July 2011 using a 3-dose primary series at 6, 10 and 14 weeks of age. Methods Through community-based surveillance, we used a retrospective cohort study design to assess OM prevalence among PCV13-vaccinated children aged 24 to 36 months in 2015. This was compared with a 2013 age-matched cohort of PCV13-unvaccinated children. OM was diagnosed by clinical inspection for chronic suppurative OM (CSOM) and tympanometry for OM with effusion (OME). CSOM was defined as draining of the middle ear with duration of more than 2 weeks and prolonged OME was defined as a flat 'type B' tympanogram. PCV13-vaccinated and PCV13-unvaccinated cohorts were compared by calculating prevalence odds ratios for OM and baseline characteristics. Results Altogether, 111 OM cases were identified; 42/433 (9.7%) in the PCV13-unvaccinated in 2013 and 69/413 (16.7%) in the PCV13-vaccinated cohort in 2015. In the 2013 baseline survey, 3/433 (0.7%) children were identified with unilateral CSOM compared to 9/413 (2.2%) in the PCV13-vaccinated cohort in 2015. Bilateral prolonged OME was diagnosed in 7/433 (1.6%) PCV13-unvaccinated children and in 12/413 (2.9%) in PCV13-vaccinated children. Proportions of children with unilateral prolonged OME were 31/433 (7.2%) in the PCV13-unvaccinated group compared with 48/413 (11.6%) in the PCV13-vaccinated group. Multivariate logistic regression analysis showed evidence that PCV13-vaccinated children in 2015 had 40% less risk of contracting OM compared to PCV13-unvaccinated children in 2013 (adjusted prevalence odds ratios = 0.60 [95% confidence interval: 0.38 to 0.94], P = 0.025). Additionally, attributable proportion estimates show that, 58% of OM infections among the PCV13-vaccinated group would still have occurred despite PCV13 vaccination. Conclusion Our findings provide significant evidence on the effect of PCV13 in decreasing OM or OME among children in this age group. It also supports justification for government's continuation of PCV13 immunization program in the absence of GAVI's funding. Further research is needed to assess the long-term impact of the PCV13 program on in OM Cameroon.
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Affiliation(s)
- John Njuma Libwea
- Health Sciences Unit, Faculty of Social Sciences, Tampere University, Tampere, Finland
- Expanded Programme on Immunization, Yaoundé, Cameroon
- Directorate for disease control, epidemics and pandemics, Ministry of Public Health, Yaoundé, Cameroon
| | - Viviane Armelle Ngomba
- Directorate for disease control, epidemics and pandemics, Ministry of Public Health, Yaoundé, Cameroon
| | - Nadesh Ashukem Taku
- Mother & Child Centre (MCH), Chantal Biya Foundation, Yaoundé, Cameroon
- Faculty of Sciences, Department of Microbiology, University of Buea, Buea, Cameroon
| | | | | | - Ninying Fointama
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Marie Kobela
- Expanded Programme on Immunization, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Heini Huhtala
- Health Sciences Unit, Faculty of Social Sciences, Tampere University, Tampere, Finland
| | - Emilienne Epee
- Directorate for disease control, epidemics and pandemics, Ministry of Public Health, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Sinata Koulla-Shiro
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
| | - Paul Koki Ndombo
- Mother & Child Centre (MCH), Chantal Biya Foundation, Yaoundé, Cameroon
- Faculty of Medicine and Biomedical Sciences, University of Yaoundé 1, Yaoundé, Cameroon
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Bilgin GM, Munira SL, Lokuge K, Glass K. Cost-effectiveness analysis of a maternal pneumococcal vaccine in low-income, high-burden settings such as Sierra Leone. PLOS GLOBAL PUBLIC HEALTH 2023; 3:e0000915. [PMID: 37619237 PMCID: PMC10449127 DOI: 10.1371/journal.pgph.0000915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Accepted: 07/01/2023] [Indexed: 08/26/2023]
Abstract
Maternal pneumococcal vaccines have been proposed as a method of protecting infants in the first few months of life. In this paper, we use results from a dynamic transmission model to assess the cost-effectiveness of a maternal pneumococcal polysaccharide vaccine from both healthcare and societal perspectives. We estimate the costs of delivering a maternal pneumococcal polysaccharide vaccine, the healthcare costs averted, and productivity losses avoided through the prevention of severe pneumococcal outcomes such as pneumonia and meningitis. Our model estimates that a maternal pneumococcal program would cost $606 (2020 USD, 95% prediction interval 437 to 779) from a healthcare perspective and $132 (95% prediction interval -1 to 265) from a societal perspective per DALY averted for one year of vaccine delivery. Hence, a maternal pneumococcal vaccine would be cost-effective from a societal perspective but not cost-effective from a healthcare perspective using Sierra Leone's GDP per capita of $527 as a cost-effectiveness threshold. Sensitivity analysis demonstrates how the choice to discount ongoing health benefits determines whether the maternal pneumococcal vaccine was deemed cost-effective from a healthcare perspective. Without discounting, the cost per DALY averted would be $292 (55% of Sierra Leone's GDP per capita) from a healthcare perspective. Further, the cost per DALY averted would be $142 (27% GDP per capita) from a healthcare perspective if PPV could be procured at the same cost relative to PCV in Sierra Leone as on the PAHO reference price list. Overall, our paper demonstrates that maternal pneumococcal vaccines have the potential to be cost-effective in low-income settings; however, the likelihood of low-income countries self-financing this intervention will depend on negotiations with vaccine providers on vaccine price. Vaccine price is the largest program cost driving the cost-effectiveness of a future maternal pneumococcal vaccine.
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Affiliation(s)
- Gizem M. Bilgin
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia
| | - Syarifah Liza Munira
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia
| | - Kamalini Lokuge
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia
| | - Kathryn Glass
- National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia
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Mueller N, Anderle R, Brachowicz N, Graziadei H, Lloyd SJ, de Sampaio Morais G, Sironi AP, Gibert K, Tonne C, Nieuwenhuijsen M, Rasella D. Model Choice for Quantitative Health Impact Assessment and Modelling: An Expert Consultation and Narrative Literature Review. Int J Health Policy Manag 2023; 12:7103. [PMID: 37579425 PMCID: PMC10461835 DOI: 10.34172/ijhpm.2023.7103] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 01/28/2023] [Indexed: 08/16/2023] Open
Abstract
BACKGROUND Health impact assessment (HIA) is a widely used process that aims to identify the health impacts, positive or negative, of a policy or intervention that is not necessarily placed in the health sector. Most HIAs are done prospectively and aim to forecast expected health impacts under assumed policy implementation. HIAs may quantitatively and/ or qualitatively assess health impacts, with this study focusing on the former. A variety of quantitative modelling methods exist that are used for forecasting health impacts, however, they differ in application area, data requirements, assumptions, risk modelling, complexities, limitations, strengths, and comprehensibility. We reviewed relevant models, so as to provide public health researchers with considerations for HIA model choice. METHODS Based on an HIA expert consultation, combined with a narrative literature review, we identified the most relevant models that can be used for health impact forecasting. We narratively and comparatively reviewed the models, according to their fields of application, their configuration and purposes, counterfactual scenarios, underlying assumptions, health risk modelling, limitations and strengths. RESULTS Seven relevant models for health impacts forecasting were identified, consisting of (i) comparative risk assessment (CRA), (ii) time series analysis (TSA), (iii) compartmental models (CMs), (iv) structural models (SMs), (v) agent-based models (ABMs), (vi) microsimulations (MS), and (vii) artificial intelligence (AI)/machine learning (ML). These models represent a variety in approaches and vary in the fields of HIA application, complexity and comprehensibility. We provide a set of criteria for HIA model choice. Researchers must consider that model input assumptions match the available data and parameter structures, the available resources, and that model outputs match the research question, meet expectations and are comprehensible to end-users. CONCLUSION The reviewed models have specific characteristics, related to available data and parameter structures, computational implementation, interpretation and comprehensibility, which the researcher should critically consider before HIA model choice.
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Affiliation(s)
- Natalie Mueller
- ISGlobal, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Rodrigo Anderle
- Institute of Collective Health (ISC), Federal University of Bahia (UFBA), Salvador, Brazil
| | | | - Helton Graziadei
- School of Applied Mathematics, Getulio Vargas Foundation, Rio de Janeiro, Brazil
| | | | | | - Alberto Pietro Sironi
- Institute of Collective Health (ISC), Federal University of Bahia (UFBA), Salvador, Brazil
| | - Karina Gibert
- Intelligent Data Science and Artificial Intelligence Research Center, Universitat Politècnica de Catalunya (IDEAI-UPC), Barcelona, Spain
| | - Cathryn Tonne
- ISGlobal, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Mark Nieuwenhuijsen
- ISGlobal, Barcelona, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
- CIBER Epidemiología y Salud Pública (CIBERESP), Madrid, Spain
| | - Davide Rasella
- ISGlobal, Barcelona, Spain
- Institute of Collective Health (ISC), Federal University of Bahia (UFBA), Salvador, Brazil
- Hospital Clínic—Universitat de Barcelona, Barcelona, Spain
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Kay EJ, Mauri M, Willcocks SJ, Scott TA, Cuccui J, Wren BW. Engineering a suite of E. coli strains for enhanced expression of bacterial polysaccharides and glycoconjugate vaccines. Microb Cell Fact 2022; 21:66. [PMID: 35449016 PMCID: PMC9026721 DOI: 10.1186/s12934-022-01792-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Accepted: 04/09/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Glycoengineering, in the biotechnology workhorse bacterium, Escherichia coli, is a rapidly evolving field, particularly for the production of glycoconjugate vaccine candidates (bioconjugation). Efficient production of glycoconjugates requires the coordinated expression within the bacterial cell of three components: a carrier protein, a glycan antigen and a coupling enzyme, in a timely fashion. Thus, the choice of a suitable E. coli host cell is of paramount importance. Microbial chassis engineering has long been used to improve yields of chemicals and biopolymers, but its application to vaccine production is sparse. RESULTS In this study we have engineered a family of 11 E. coli strains by the removal and/or addition of components rationally selected for enhanced expression of Streptococcus pneumoniae capsular polysaccharides with the scope of increasing yield of pneumococcal conjugate vaccines. Importantly, all strains express a detoxified version of endotoxin, a concerning contaminant of therapeutics produced in bacterial cells. The genomic background of each strain was altered using CRISPR in an iterative fashion to generate strains without antibiotic markers or scar sequences. CONCLUSIONS Amongst the 11 modified strains generated in this study, E. coli Falcon, Peregrine and Sparrowhawk all showed increased production of S. pneumoniae serotype 4 capsule. Eagle (a strain without enterobacterial common antigen, containing a GalNAc epimerase and PglB expressed from the chromosome) and Sparrowhawk (a strain without enterobacterial common antigen, O-antigen ligase and chain length determinant, containing a GalNAc epimerase and chain length regulators from Streptococcus pneumoniae) respectively produced an AcrA-SP4 conjugate with 4 × and 14 × more glycan than that produced in the base strain, W3110. Beyond their application to the production of pneumococcal vaccine candidates, the bank of 11 new strains will be an invaluable resource for the glycoengineering community.
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Affiliation(s)
- Emily J Kay
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Marta Mauri
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Sam J Willcocks
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Timothy A Scott
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Jon Cuccui
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK
| | - Brendan W Wren
- Department of Infection Biology, London School of Hygiene & Tropical Medicine, London, UK.
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Pecenka C, Usuf E, Hossain I, Sambou S, Vodicka E, Atherly D, Mackenzie G. Pneumococcal conjugate vaccination in The Gambia: health impact, cost effectiveness and budget implications. BMJ Glob Health 2021; 6:bmjgh-2021-007211. [PMID: 34916274 PMCID: PMC8679103 DOI: 10.1136/bmjgh-2021-007211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 11/29/2021] [Indexed: 11/04/2022] Open
Abstract
INTRODUCTION Introducing pneumococcal conjugate vaccine (PCV) in many low-income countries has contributed to reductions in global childhood deaths caused by Streptococcus pneumoniae. Many low-income countries, however, will soon reach an economic status leading to transition from Gavi, the Vaccine Alliance vaccine funding support and then face increased expenditure to continue PCV programmes. Evaluating the cost-effectiveness of PCV in low-income countries will inform such country decisions. METHODS We used empiric data on the costs of vaccine delivery and pneumococcal disease and PCV programme impact on disease among children less than 5 years old in The Gambia. We used the UNIVAC cost-effectiveness modelling tool to compare the impact and cost-effectiveness of pneumococcal conjugate vaccination to no vaccination over 20 birth cohorts starting in 2011. We calculated costs per disability-adjusted-life-year (DALY) averted from government and societal perspectives and undertook scenario and probabilistic sensitivity analysis. RESULTS We projected that, over 20 years, PCV in The Gambia could avert 117 000 total disease episodes in children less than 5 years old, including outpatient and hospitalised pneumonia, pneumococcal sepsis and meningitis (including sequelae). Vaccination could avert 9000 outpatient pneumonia visits, 88 000 hospitalisations and 3300 deaths due to pneumonia, meningitis and sepsis. Approximately 100 000 DALYs are expected to be averted. Averted visits and hospitalisations represent US$4 million in healthcare costs expected to be saved by the government and US$7.3 million if household costs are included. The cost of the vaccination programme is estimated at US$2 million. In the base scenario, most alternative scenarios and nearly 90% of the probabilistic scenarios, pneumococcal vaccination is cost saving in The Gambia. CONCLUSION Pneumococcal conjugate vaccination is expected to generate substantial health gains and is likely to be cost saving in The Gambia. Policymakers in similar settings should be confident to maintain their PCV programmes.
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Affiliation(s)
- Clint Pecenka
- Center for Vaccine Innovation and Access, PATH, Seattle, Washington, USA
| | - Effua Usuf
- Disease Control and Elimination, Medical Research Council The Gambia, Banjul, Gambia
| | - Ilias Hossain
- Disease Control and Elimination, Medical Research Council The Gambia, Banjul, Gambia
| | - Sana Sambou
- Ministry of Health, Government of the Gambia, Banjul, Gambia
| | - Elisabeth Vodicka
- Center for Vaccine Innovation and Access, PATH, Seattle, Washington, USA
| | - Deborah Atherly
- Center for Vaccine Innovation and Access, PATH, Seattle, Washington, USA
| | - Grant Mackenzie
- Disease Control and Elimination, MRC Unit The Gambia at LSHTM, Banjul, Gambia.,London School of Hygiene & Tropical Medicine, London, UK
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Njuguna HN, Zaki SR, Roberts DJ, Rogena EA, Walong E, Fligner CL, Keating MK, Gachii AK, Maleche-Obimbo E, Irimu G, Mathaiya J, Orata N, Lopokoiyit R, Michuki J, Emukule GO, Onyango CO, Gikunju S, Owuor C, Muturi PK, Bunei M, Gloria Carvalho M, Fields B, Mott JA, Widdowson MA, Chaves SS. Postmortem Study of Cause of Death Among Children Hospitalized With Respiratory Illness in Kenya. Pediatr Infect Dis J 2021; 40:715-722. [PMID: 33967229 PMCID: PMC8274582 DOI: 10.1097/inf.0000000000003159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/25/2021] [Indexed: 11/26/2022]
Abstract
BACKGROUND In resource-limited settings, acute respiratory infections continue to be the leading cause of death in young children. We conducted postmortem investigations in children <5 years hospitalized with a clinical diagnosis of respiratory disease at Kenya's largest referral hospital. METHODS We collected respiratory and other tissues postmortem to examine pathologic processes using histology, molecular and immunohistochemistry assays. Nasopharyngeal, trachea, bronchi and lung specimens were tested using 21-target respiratory pathogen real-time reverse transcription polymerase chain reaction assays deployed on Taqman Array Cards. Expert panels reviewed all findings to determine causes of death and associated pathogens. RESULTS From 2014 to 2015, we investigated 64 pediatric deaths (median age 7 months). Pneumonia was determined as cause of death in 70% (42/52) of cases where death was associated with an infectious disease process. The main etiologies of pneumonia deaths were respiratory syncytial virus (RSV) (n = 7, 19%), Pneumocystis jirovecii (n = 7, 19%), influenza A (n = 5, 14%) and Streptococcus pneumoniae (n = 5, 14%)-10% of cases had multi-pathogen involvement. Among the other 10 deaths associated with a nonpneumonia infectious process, 4 did not have an etiology assigned, the others were associated with miliary tuberculosis (2), cerebral thrombosis due to HIV (1), Enterobacteriaceae (1), rotavirus (1), and 1 case of respiratory infection with severe hypokalemia associated with RSV. CONCLUSIONS In spite of well-established vaccination programs in Kenya, some deaths were still vaccine preventable. Accelerated development of RSV monoclonal antibodies and vaccines, introduction of seasonal influenza vaccination, and maintenance or improved uptake of existing vaccines can contribute to further reductions in childhood mortality.
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Affiliation(s)
- Henry N. Njuguna
- From the Influenza Program, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
| | - Sherif R. Zaki
- Centers for Disease Control and Prevention (CDC), Infectious Diseases Pathology Branch, Atlanta, Georgia
| | - Drucilla J. Roberts
- Obstetric and Perinatal Pathology, Massachusetts General Hospital, Boston, Massachusetts
| | - Emily A. Rogena
- Department of Pathology, University of Nairobi, Nairobi, Kenya
| | - Edwin Walong
- Department of Pathology, University of Nairobi, Nairobi, Kenya
| | | | - M. Kelly Keating
- Centers for Disease Control and Prevention (CDC), Infectious Diseases Pathology Branch, Atlanta, Georgia
| | - Andrew K. Gachii
- Department of Pathology, Kenyatta National Hospital, Nairobi, Kenya
| | | | - Grace Irimu
- Department of Pathology, University of Nairobi, Nairobi, Kenya
| | - John Mathaiya
- Department of Pathology, University of Nairobi, Nairobi, Kenya
| | - Noelle Orata
- Department of Pathology, University of Nairobi, Nairobi, Kenya
| | | | - Jackson Michuki
- Department of Pathology, University of Nairobi, Nairobi, Kenya
| | - Gideon O. Emukule
- From the Influenza Program, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
| | - Clayton O. Onyango
- From the Influenza Program, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
| | - Stella Gikunju
- Influenza Program, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Collins Owuor
- Influenza Program, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Peter K. Muturi
- Influenza Program, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Milka Bunei
- Influenza Program, Kenya Medical Research Institute (KEMRI), Nairobi, Kenya
| | - Maria Gloria Carvalho
- Centers for Disease Control and Prevention (CDC), Respiratory Diseases Branch, Atlanta, Georgia
| | - Barry Fields
- From the Influenza Program, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
- Centers for Disease Control and Prevention (CDC), Division of Global Health Protection, Atlanta, Georgia
| | - Joshua A. Mott
- Centers for Disease Control and Prevention (CDC), Influenza Division, Atlanta, Georgia
| | - Marc-Alain Widdowson
- From the Influenza Program, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
- Institute of Tropical Medicine, Antwerp, Belgium
| | - Sandra S. Chaves
- From the Influenza Program, Centers for Disease Control and Prevention (CDC), Nairobi, Kenya
- Centers for Disease Control and Prevention (CDC), Influenza Division, Atlanta, Georgia
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9
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Janusz CB, Mutua MK, Wagner AL, Boulton ML. New Vaccine Introduction and Childhood Vaccination Timeliness in Two Urban, Informal Settlements in Nairobi, Kenya. Am J Trop Med Hyg 2021; 105:245-253. [PMID: 33999852 DOI: 10.4269/ajtmh.21-0006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Accepted: 03/22/2021] [Indexed: 11/07/2022] Open
Abstract
New vaccine introduction accompanied by social mobilization activities could contribute to improved routine immunization timeliness. This study assesses the impact of Kenya's introduction of pneumococcal conjugate vaccine (PCV) on the timeliness of routine childhood vaccination in two informal, urban settlements in Nairobi. Data collected from 2007 to 2015 as part of a demographic surveillance system were used to estimate annual vaccination delays of ≥ 4 weeks among children aged 12-23 months in the period before and after the introduction of PCV in Kenya. Binomial segmented regression models using generalized estimating equations examined the association between vaccine introduction and timeliness of routine immunization. Over half of all children vaccinated in the two urban areas received one or more doses ≥ 4 weeks after the recommended age. The timeliness of routine immunization showed slight improvements or nonsignificant changes during the years following PCV introduction compared with the preceding years (adjusted prevalence ratio [aPR]: 0.67, 95% CI: 0.45-0.99 for Bacille Calmette-Guerin receipt; aPR: 0.59, 95% CI: 0.41-0.83 for third dose Pentavalent receipt; aPR: 1.19, 95% CI: 0.99-1.42 for measles). However, as of 2015, delayed vaccination remained prevalent in children, particularly among the poorest residing in the settlements. Many sub-Saharan African countries have introduced new life-saving vaccines into their routine childhood immunization schedule. Additional evidence regarding the positive or neutral influence of new vaccine introduction on the performance of delivery systems provides further justification to sustain the inclusion of these more costly vaccines in the immunization schedule.
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Affiliation(s)
- Cara Bess Janusz
- 1Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan.,2The Institute of Global Health Equity, University of Michigan, Ann Arbor, Michigan
| | - Martin K Mutua
- 3Data Measurements and Evaluation, African Population and Health Research Center, Nairobi, Kenya
| | - Abram L Wagner
- 1Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan.,2The Institute of Global Health Equity, University of Michigan, Ann Arbor, Michigan
| | - Matthew L Boulton
- 1Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan.,2The Institute of Global Health Equity, University of Michigan, Ann Arbor, Michigan.,4Department of Internal Medicine, Infectious Disease Division, Michigan Medicine, Ann Arbor, Michigan
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10
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Watts E, Sim SY, Constenla D, Sriudomporn S, Brenzel L, Patenaude B. Economic Benefits of Immunization for 10 Pathogens in 94 Low- and Middle-Income Countries From 2011 to 2030 Using Cost-of-Illness and Value-of-Statistical-Life Approaches. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2021; 24:78-85. [PMID: 33431157 DOI: 10.1016/j.jval.2020.07.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 06/23/2020] [Accepted: 07/12/2020] [Indexed: 06/12/2023]
Abstract
OBJECTIVES Vaccination has prevented millions of deaths and cases of disease in low- and middle-income countries (LMICs). During the Decade of Vaccines (2011-2020), international organizations, including the World Health Organization and Gavi, the Vaccine Alliance, focused on new vaccine introduction and expanded coverage of existing vaccines. As Gavi, other organizations, and country governments look to the future, we aimed to estimate the economic benefits of immunization programs made from 2011 to 2020 and potential gains in the future decade. METHODS We used estimates of cases and deaths averted by vaccines against 10 pathogens in 94 LMICs to estimate the economic value of immunization. We applied 3 approaches-cost of illness averted (COI), value of statistical life (VSL), and value of statistical life-year (VSLY)-to estimate observable and unobservable economic benefits between 2011 and 2030. RESULTS From 2011 to 2030, immunization would avert $1510.4 billion ($674.3-$2643.2 billion) (2018 USD) in costs of illness in the 94 modeled countries, compared with the counterfactual of no vaccination. Using the VSL approach, immunization would generate $3436.7 billion ($1615.8-$5657.2 billion) in benefits. Applying the VSLY approach, $5662.7 billion ($2547.2-$9719.4) in benefits would be generated. CONCLUSION Vaccination has generated significant economic benefits in LMICs in the past decade. To reach predicted levels of economic benefits, countries and international donor organizations need to meet coverage projections outlined in the Gavi Operational Forecast. Estimates generated using the COI, VSL, or VSLY approach may be strategically used by donor agencies, decision makers, and advocates to inform investment cases and advocacy campaigns.
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Affiliation(s)
- Elizabeth Watts
- International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | - So Yoon Sim
- Department of Immunization, Vaccines and Biologicals (IVB), World Health Organization, Geneve, GE, CH
| | | | - Salin Sriudomporn
- International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
| | | | - Bryan Patenaude
- International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA; Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA
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11
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Dawa J, Emukule GO, Barasa E, Widdowson MA, Anzala O, van Leeuwen E, Baguelin M, Chaves SS, Eggo RM. Seasonal influenza vaccination in Kenya: an economic evaluation using dynamic transmission modelling. BMC Med 2020; 18:223. [PMID: 32814581 PMCID: PMC7438179 DOI: 10.1186/s12916-020-01687-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 06/29/2020] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND There is substantial burden of seasonal influenza in Kenya, which led the government to consider introducing a national influenza vaccination programme. Given the cost implications of a nationwide programme, local economic evaluation data are needed to inform policy on the design and benefits of influenza vaccination. We set out to estimate the cost-effectiveness of seasonal influenza vaccination in Kenya. METHODS We fitted an age-stratified dynamic transmission model to active surveillance data from patients with influenza from 2010 to 2018. Using a societal perspective, we developed a decision tree cost-effectiveness model and estimated the incremental cost-effectiveness ratio (ICER) per disability-adjusted life year (DALY) averted for three vaccine target groups: children 6-23 months (strategy I), 2-5 years (strategy II) and 6-14 years (strategy III) with either the Southern Hemisphere influenza vaccine (Strategy A) or Northern Hemisphere vaccine (Strategy B) or both (Strategy C: twice yearly vaccination campaigns, or Strategy D: year-round vaccination campaigns). We assessed cost-effectiveness by calculating incremental net monetary benefits (INMB) using a willingness-to-pay (WTP) threshold of 1-51% of the annual gross domestic product per capita ($17-$872). RESULTS The mean number of infections across all ages was 2-15 million per year. When vaccination was well timed to influenza activity, the annual mean ICER per DALY averted for vaccinating children 6-23 months ranged between $749 and $1385 for strategy IA, $442 and $1877 for strategy IB, $678 and $4106 for strategy IC and $1147 and $7933 for strategy ID. For children 2-5 years, it ranged between $945 and $1573 for strategy IIA, $563 and $1869 for strategy IIB, $662 and $4085 for strategy IIC, and $1169 and $7897 for strategy IID. For children 6-14 years, it ranged between $923 and $3116 for strategy IIIA, $1005 and $2223 for strategy IIIB, $883 and $4727 for strategy IIIC and $1467 and $6813 for strategy IIID. Overall, no vaccination strategy was cost-effective at the minimum ($17) and median ($445) WTP thresholds. Vaccinating children 6-23 months once a year had the highest mean INMB value at $872 (WTP threshold upper limit); however, this strategy had very low probability of the highest net benefit. CONCLUSION Vaccinating children 6-23 months once a year was the most favourable vaccination option; however, the strategy is unlikely to be cost-effective given the current WTP thresholds.
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Affiliation(s)
- Jeanette Dawa
- KAVI-Institute of Clinical Research, College of Health Sciences, University of Nairobi, Nairobi, Kenya.
- Washington State University Global Health Programs Kenya Office, Nairobi, Kenya.
| | - Gideon O Emukule
- Influenza Program, Centers for Disease Control and Prevention, Nairobi, Kenya
| | - Edwine Barasa
- Health Economics Research Unit, KEMRI Wellcome Trust Research Programme, Nairobi, Kenya
- Center for Tropical Medicine, Nuffield Department of Medicine, University of Oxford, Oxford, UK
| | - Marc Alain Widdowson
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Nairobi, Kenya
- Division of Global Health Protection, Center for Global Health, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Omu Anzala
- KAVI-Institute of Clinical Research, College of Health Sciences, University of Nairobi, Nairobi, Kenya
| | | | - Marc Baguelin
- London School of Hygiene & Tropical Medicine, London, UK
- Imperial College London, London, UK
| | - Sandra S Chaves
- Influenza Program, Centers for Disease Control and Prevention, Nairobi, Kenya
- Influenza Division, National Center for Immunization and Respiratory Diseases, US Centers for Disease Control and Prevention, Atlanta, GA, USA
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12
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Lourenço J, Obolski U, Swarthout TD, Gori A, Bar-Zeev N, Everett D, Kamng'ona AW, Mwalukomo TS, Mataya AA, Mwansambo C, Banda M, Gupta S, French N, Heyderman RS. Determinants of high residual post-PCV13 pneumococcal vaccine-type carriage in Blantyre, Malawi: a modelling study. BMC Med 2019; 17:219. [PMID: 31801542 PMCID: PMC6894346 DOI: 10.1186/s12916-019-1450-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Accepted: 10/24/2019] [Indexed: 01/10/2023] Open
Abstract
BACKGROUND In November 2011, Malawi introduced the 13-valent pneumococcal conjugate vaccine (PCV13) into the routine infant schedule. Four to 7 years after introduction (2015-2018), rolling prospective nasopharyngeal carriage surveys were performed in the city of Blantyre. Carriage of Streptococcus pneumoniae vaccine serotypes (VT) remained higher than reported in high-income countries, and impact was asymmetric across age groups. METHODS A dynamic transmission model was fit to survey data using a Bayesian Markov-chain Monte Carlo approach, to obtain insights into the determinants of post-PCV13 age-specific VT carriage. RESULTS Accumulation of naturally acquired immunity with age and age-specific transmission potential were both key to reproducing the observed data. VT carriage reduction peaked sequentially over time, earlier in younger and later in older age groups. Estimated vaccine efficacy (protection against carriage) was 66.87% (95% CI 50.49-82.26%), similar to previous estimates. Ten-year projected vaccine impact (VT carriage reduction) among 0-9 years old was lower than observed in other settings, at 76.23% (CI 95% 68.02-81.96%), with sensitivity analyses demonstrating this to be mainly driven by a high local force of infection. CONCLUSIONS There are both vaccine-related and host-related determinants of post-PCV13 pneumococcal VT transmission in Blantyre with vaccine impact determined by an age-specific, local force of infection. These findings are likely to be generalisable to other Sub-Saharan African countries in which PCV impact on carriage (and therefore herd protection) has been lower than desired, and have implications for the interpretation of post-PCV carriage studies and future vaccination programs.
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Affiliation(s)
- J Lourenço
- Department of Zoology, University of Oxford, Oxford, UK.
| | - U Obolski
- School of Public Health, Tel Aviv University, Tel Aviv, Israel.,Porter School of the Environment and Earth Sciences, Tel Aviv University, Tel Aviv, Israel
| | - T D Swarthout
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Clinical Sciences Department, Liverpool School of Tropical Medicine, Liverpool, UK
| | - A Gori
- NIHR Mucosal Pathogens Research Unit, Division of Infection & Immunity, University College London, London, UK
| | - N Bar-Zeev
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, USA
| | - D Everett
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,The Queens Medical Research Institute, University of Edinburgh, Edinburgh, UK
| | - A W Kamng'ona
- Department of Biomedical Sciences, College of Medicine, University of Malawi, Blantyre, Malawi
| | - T S Mwalukomo
- Department of Medicine, College of Medicine, University of Malawi, Blantyre, Malawi
| | - A A Mataya
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi
| | | | - M Banda
- Ministry of Education, Blantyre, Malawi
| | - S Gupta
- Department of Zoology, University of Oxford, Oxford, UK
| | - N French
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,Centre for Global Vaccine Research, Institute of Infection and Global Health, University of Liverpool, Liverpool, UK
| | - R S Heyderman
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, Blantyre, Malawi.,NIHR Mucosal Pathogens Research Unit, Division of Infection & Immunity, University College London, London, UK
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13
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van Zandvoort K, Checchi F, Diggle E, Eggo RM, Gadroen K, Mulholland K, McGowan CR, le Polain de Waroux O, Rao VB, Satzke C, Flasche S. Pneumococcal conjugate vaccine use during humanitarian crises. Vaccine 2019; 37:6787-6792. [PMID: 31562004 DOI: 10.1016/j.vaccine.2019.09.038] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 08/16/2019] [Accepted: 09/09/2019] [Indexed: 11/16/2022]
Abstract
Streptococcus pneumoniae is a common human commensal that causes a sizeable part of the overall childhood mortality in low income settings. Populations affected by humanitarian crises are at especially high risk, because a multitude of risk factors that are enhanced during crises increase pneumococcal transmission and disease severity. Pneumococcal conjugate vaccines (PCVs) provide effective protection and have been introduced into the majority of routine childhood immunisation programmes globally, though several barriers have hitherto limited their uptake during humanitarian crises. When PCV coverage cannot be sustained during crises or when PCV has not been part of routine programmes, mass vaccination campaigns offer a quick acting and programmatically feasible bridging solution until services can be restored. However, we currently face a paucity of evidence on which to base the structure of such campaigns. We believe that, now that PCV can be procured at a substantially reduced price through the Humanitarian Mechanism, this lack of information is a remaining hurdle to PCV use in humanitarian crises. Considering the difficulties in conducting research in crises, we propose an evidence generation pathway consisting of primary data collection in combination with mathematical modelling followed by quasi-experimental evaluation of a PCV intervention, which can inform on optimal vaccination strategies that consider age targeting, dosing regimens and impact duration.
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Affiliation(s)
- Kevin van Zandvoort
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK.
| | - Francesco Checchi
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | | | - Rosalind M Eggo
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
| | - Kartini Gadroen
- Médecins Sans Frontières, Amsterdam, the Netherlands; Department of Medical Informatics, Erasmus MC, Rotterdam, the Netherlands
| | - Kim Mulholland
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Murdoch Children's Research Institute, University of Melbourne, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Catherine R McGowan
- Save the Children UK, London, UK; Department of Public Health, Environments, and Society, London School of Hygiene & Tropical Medicine. London, UK
| | - Olivier le Polain de Waroux
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK; UK Public Health Rapid Support Team, London, UK; Public Health England, London, UK
| | - V Bhargavi Rao
- Manson Unit, Médecins Sans Frontières (MSF UK), London, UK
| | - Catherine Satzke
- Murdoch Children's Research Institute, University of Melbourne, Royal Children's Hospital, Melbourne, Victoria, Australia
| | - Stefan Flasche
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical Medicine, London, UK
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14
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Simonsen L, van Wijhe M, Taylor R. Are expensive vaccines the best investment in low-income and middle-income countries? THE LANCET GLOBAL HEALTH 2019; 7:e548-e549. [DOI: 10.1016/s2214-109x(19)30040-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2019] [Accepted: 01/11/2019] [Indexed: 11/30/2022] Open
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