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Kouakou YE, Dely ID, Doumbia M, Ouattara A, N'da EJ, Brou KE, Zouzou YA, Cissé G, Koné B. Methodological framework for assessing malaria risk associated with climate change in Côte d'Ivoire. GEOSPATIAL HEALTH 2024; 19. [PMID: 39221818 DOI: 10.4081/gh.2024.1285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Accepted: 06/30/2024] [Indexed: 09/04/2024]
Abstract
Malaria is the leading cause of morbidity among children under five years of age and pregnant women in Côte d'Ivoire. We assessed the geographical distribution of its risk in all climatic zones of the country based on the Fifth Assessment Report (AR5) of the United Nations Intergovernmental Panel on Climate Change (IPCC) approach to climate risk analysis. This methodology considers three main driving components affecting the risk: Hazard, exposure and vulnerability. Considering the malaria impact chain, various variables were identified for each of the risk factors and for each variable, a measurable indicator was identified. These indicators were then standardized, weighted through a participatory approach based on expert judgement and finally aggregated to calculate current and future risk. With regard to the four climatic zones in the country: Attieen (sub-equatorial regime) in the South, Baouleen (humid tropical) in the centre, Sudanese or equatorial (tropical transition regime) in the North and the mountainous (humid) in the West. Malaria risk among pregnant women and children under 5 was found to be higher in the mountainous and the Baouleen climate, with the hazard highest in the mountainous climate and Exposure very high in the Attieen climate. The most vulnerable districts were those in Baouleen, Attieen and the mountainous climates. By 2050, the IPCC representative concentration pathway (RCP) 4.5 and 8.5 scenarios predict an increase in risk in almost all climatic zones, compared to current levels, with the former considering a moderate scenario, with an emissions peak around 2040 followed by a decline and RCP 8.5 giving the highest baseline emissions scenario, in which emissions continue to rise. It is expected that the AR5 approach to climate risk analysis will be increasingly used in climate risk assessment studies so that it can be better assessed at a variety of scales.
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Affiliation(s)
- Yao Etienne Kouakou
- Nangui Abrogoua University, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan.
| | - Iba Dieudonné Dely
- Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Péléféro Gon Coulibaly University, Korhogo.
| | - Madina Doumbia
- Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Péléféro Gon Coulibaly University, Korhogo.
| | | | - Effah Jemima N'da
- Nangui Abrogoua University, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan.
| | - Koffi Evrard Brou
- Nangui Abrogoua University, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan.
| | - Yao Anicet Zouzou
- Nangui Abrogoua University, Abidjan, Côte d'Ivoire; Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan.
| | - Guéladio Cissé
- Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Swiss Tropical and Public Health Institute, University of Basel.
| | - Brama Koné
- Centre Suisse de Recherches Scientifique en Côte d'Ivoire, Abidjan, Côte d'Ivoire; Péléféro Gon Coulibaly University, Korhogo.
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Yihunie W, Kebede B, Tegegne BA, Getachew M, Abebe D, Aschale Y, Belew H, Bahiru B. Systematic Review of Safety of RTS,S with AS01 and AS02 Adjuvant Systems Using Data from Randomized Controlled Trials in Infants, Children, and Adults. Clin Pharmacol 2023; 15:21-32. [PMID: 36941908 PMCID: PMC10024506 DOI: 10.2147/cpaa.s400155] [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: 12/15/2022] [Accepted: 03/07/2023] [Indexed: 03/16/2023] Open
Abstract
Background Emergence of antimalarial drugs and insecticides resistance alarms scientists to develop a safe and effective malaria vaccine. A pre-erythrocytic malaria vaccine called RTS,S has made great strides. Aim The review was aimed to assess the safety of the candidate malaria vaccine RTS,S with AS01 and AS02 adjuvants using data from Phase I-III randomized controlled clinical trials (RCTs). Methods This systematic review was conducted based on PRISMA 2020. Regardless of time of publication year, all articles related with safety of RTS,S, RCTs published in the English language were included in the study. The last search of databases, and registry was conducted on 30 May, 2022. Pubmed, Google Scholar, Cochrane Library, Wiley Online Library, and Clinical trials.gov were thoroughly searched for accessible RCTs on the safety of RTS,S malaria vaccine. The studies were screened in three steps: duplicate removal, title and abstract screening, and full-text review. The included studies' bias risk was assessed using the Cochrane risk of bias tool for RCTs. This systematic review is registered at Prospero (registration number: CRD42021285888). The qualitative descriptive findings from the included published studies were reported stratified by clinical trial phases. Findings A total of thirty-five eligible safety studies were identified. Injection site pain and swelling, febrile convulsion, fever, headache, meningitis, fatigue, gastroenteritis, myalgia, pneumonia, reactogenicity, and anemia were the most commonly reported adverse events. Despite few clinical trials reported serious adverse events, none of them were related to vaccination. Conclusion Most of the adverse events observed from RTS,S/AS01 and RTS,S/AS02 malaria vaccines were reported in the control group and shared by other vaccines. Hence, the authors concluded that both RTS,S/AS01 and RTS,S/AS02 malaria vaccines are safe.
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Affiliation(s)
- Wubetu Yihunie
- Department of Pharmacy, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Bekalu Kebede
- Department of Pharmacy, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Bantayehu Addis Tegegne
- Department of Pharmacy, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Melese Getachew
- Department of Pharmacy, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Dehnnet Abebe
- Department of Pharmacy, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Yibeltal Aschale
- Department of Medical Laboratory Science, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Habtamu Belew
- Department of Medical Laboratory Science, College of Health Sciences, Debre Markos University, Debre Markos, Ethiopia
| | - Bereket Bahiru
- Department of Pharmacy, College of Medicine and health sciences, Bahir Dar University, Bahir Dar, Ethiopia
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Bell GJ, Goel V, Essone P, Dosoo D, Adu B, Mensah BA, Gyaase S, Wiru K, Mougeni F, Osei M, Minsoko P, Sinai C, Niaré K, Juliano JJ, Hudgens M, Ghansah A, Kamthunzi P, Mvalo T, Agnandji ST, Bailey JA, Asante KP, Emch M. Malaria Transmission Intensity Likely Modifies RTS, S/AS01 Efficacy Due to a Rebound Effect in Ghana, Malawi, and Gabon. J Infect Dis 2022; 226:1646-1656. [PMID: 35899811 PMCID: PMC10205900 DOI: 10.1093/infdis/jiac322] [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: 05/20/2022] [Accepted: 07/26/2022] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND RTS,S/AS01 is the first malaria vaccine to be approved and recommended for widespread implementation by the World Health Organization (WHO). Trials reported lower vaccine efficacies in higher-incidence sites, potentially due to a "rebound" in malaria cases in vaccinated children. When naturally acquired protection in the control group rises and vaccine protection in the vaccinated wanes concurrently, malaria incidence can become greater in the vaccinated than in the control group, resulting in negative vaccine efficacies. METHODS Using data from the 2009-2014 phase III trial (NCT00866619) in Lilongwe, Malawi; Kintampo, Ghana; and Lambaréné, Gabon, we evaluate this hypothesis by estimating malaria incidence in each vaccine group over time and in varying transmission settings. After estimating transmission intensities using ecological variables, we fit models with 3-way interactions between vaccination, time, and transmission intensity. RESULTS Over time, incidence decreased in the control group and increased in the vaccine group. Three-dose efficacy in the lowest-transmission-intensity group (0.25 cases per person-year [CPPY]) decreased from 88.2% to 15.0% over 4.5 years, compared with 81.6% to -27.7% in the highest-transmission-intensity group (3 CPPY). CONCLUSIONS These findings suggest that interventions, including the fourth RTS,S dose, that protect vaccinated individuals during the potential rebound period should be implemented for high-transmission settings.
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Affiliation(s)
- Griffin J Bell
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Varun Goel
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Paulin Essone
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - David Dosoo
- Kintampo Health Research Centre, Kintampo, Ghana
| | - Bright Adu
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | | | | | - Kenneth Wiru
- Kintampo Health Research Centre, Kintampo, Ghana
| | - Fabrice Mougeni
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Musah Osei
- Kintampo Health Research Centre, Kintampo, Ghana
| | - Pamela Minsoko
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
| | - Cyrus Sinai
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Karamoko Niaré
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Michael Hudgens
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Anita Ghansah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | | | | | - Selidji Todagbe Agnandji
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon
- Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, Rhode Island, USA
| | | | - Michael Emch
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA
- Carolina Population Center, University of North Carolina, Chapel Hill, North Carolina, USA
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Nadeem AY, Shehzad A, Islam SU, Al-Suhaimi EA, Lee YS. Mosquirix™ RTS, S/AS01 Vaccine Development, Immunogenicity, and Efficacy. Vaccines (Basel) 2022; 10:vaccines10050713. [PMID: 35632469 PMCID: PMC9143879 DOI: 10.3390/vaccines10050713] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/11/2022] [Accepted: 04/17/2022] [Indexed: 12/10/2022] Open
Abstract
Malaria is a parasitic infection caused by bites from Plasmodium falciparum (P. falciparum)-infected mosquitoes with a present scale of symptoms ranging from moderate fever to neurological disorders. P. falciparum is the most lethal of the five strains of malaria, and is a major case of morbidity and mortality in endemic regions. Recent advancements in malaria diagnostic tools and prevention strategies have improved conjugation antimalarial therapies using fumigation and long-lasting insecticidal sprays, thus lowering malarial infections. Declines in the total number of infected individuals have been correlated with antimalarial drugs. Despite this, malaria remains a major health threat, affecting more than 30 million men, women, and children around the globe, and 20 percent of all children around the globe have malaria parasites in their blood. To overcome this life-threatening condition, novel therapeutic strategies, including immunization, are urgently needed to tackle this infection around the world. In line with this, the development of the RTS, S vaccine was a significant step forward in the fight against malaria. RTS, S is a vaccine for P. falciparum in which R specifies central repeat units, T the T-cell epitopes, and S indicates surface antigen. The RTS, S/AS01 malarial vaccine was synthesized and screened in several clinical trials between 2009 and 2014, involving thousands of young children in seven African countries, showing that children who received the vaccine did not suffer from severe malaria. Mosquirix™ was approved by the World Health Organization in 2021, indicating it to be safe and advocating its integration into routine immunization programs and existing malaria control measures. This paper examines the various stages of the vaccine’s development, including the evaluation of its immunogenicity and efficacy on the basis of a total of 2.3 million administered doses through a routine immunization program. The protection and effectiveness provided by the vaccine are strong, and evidence shows that it can be effectively delivered through the routine child immunization platform. The economic cost of the vaccine remains to be considered.
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Affiliation(s)
- Aroosa Younis Nadeem
- Department of Biomedical Sciences, School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan; (A.Y.N.); (A.S.)
| | - Adeeb Shehzad
- Department of Biomedical Sciences, School of Mechanical and Manufacturing Engineering (SMME), National University of Sciences and Technology (NUST), Islamabad 44000, Pakistan; (A.Y.N.); (A.S.)
| | - Salman Ul Islam
- Department of Pharmacy, CECOS University, Peshawar 25000, Pakistan;
| | - Ebtesam A. Al-Suhaimi
- Biology Department, College of Science and Institute for Research and Medical Consultations (IRMC), Imam Abdulrahman Bin Faisal University, Dammam 31441, Saudi Arabia;
| | - Young Sup Lee
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of Natural Sciences, Kyungpook National University, Daegu 41566, Korea
- Correspondence: ; Tel.: +82-53-950-6353; Fax: +82-53-943-2762
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Efforts Made to Eliminate Drug-Resistant Malaria and Its Challenges. BIOMED RESEARCH INTERNATIONAL 2021; 2021:5539544. [PMID: 34497848 PMCID: PMC8421183 DOI: 10.1155/2021/5539544] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 08/09/2021] [Indexed: 01/01/2023]
Abstract
Since 2000, a good deal of progress has been made in malaria control. However, there is still an unacceptably high burden of the disease and numerous challenges limiting advancement towards its elimination and ultimate eradication. Among the challenges is the antimalarial drug resistance, which has been documented for almost all antimalarial drugs in current use. As a result, the malaria research community is working on the modification of existing treatments as well as the discovery and development of new drugs to counter the resistance challenges. To this effect, many products are in the pipeline and expected to be marketed soon. In addition to drug and vaccine development, mass drug administration (MDA) is under scientific scrutiny as an important strategy for effective utilization of the developed products. This review discusses the challenges related to malaria elimination, ongoing approaches to tackle the impact of drug-resistant malaria, and upcoming antimalarial drugs.
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Bell GJ, Agnandji ST, Asante KP, Ghansah A, Kamthunzi P, Emch M, Bailey JA. Impacts of Ecology, Parasite Antigenic Variation, and Human Genetics on RTS,S/AS01e Malaria Vaccine Efficacy. CURR EPIDEMIOL REP 2021; 8:79-88. [PMID: 34367877 PMCID: PMC8324449 DOI: 10.1007/s40471-021-00271-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2021] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Global malaria elimination has little chance of success without an effective vaccine. The first malaria vaccine, RTS,S/AS01e, demonstrated moderate efficacy against clinical malaria in phase III trials and is undergoing large-scale effectiveness trials in Africa. Importantly, the vaccine did not perform equally well between phase III study sites. Though reasons for the moderate efficacy and this variation are unclear, various mechanisms have been suggested. This review summarizes the recent literature on such mechanisms, with a focus on those involving landscape ecology, parasite antigenic variation, and human host genetic differences. RECENT FINDINGS Transmission intensity may have a role pre- and post-vaccination in modulating immune responses to the vaccine. Furthermore, malaria incidence may "rebound" in vaccinated populations living in high transmission intensity settings. There is growing evidence that both genetic variation in the parasite circumsporozoite protein and variation of human host genetic factors affect RTS,S vaccine efficacy. These genetic factors may be interacting in complex ways to produce variation in the natural and vaccine-induced immune responses that protect against malaria. SUMMARY Due to the modest efficacy of RTS,S/AS01e, the combinations of factors (ecological, parasite, human host) impacting its effectiveness must be clearly understood, as this information will be critical for implementation policy and future vaccine designs.
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Affiliation(s)
- Griffin J. Bell
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Selidji Todagbe Agnandji
- Centre de Recherches Médicales de Lambaréné, Lambaréné, Gabon ,Institute of Tropical Medicine, University of Tübingen, Tübingen, Germany
| | | | - Anita Ghansah
- Noguchi Memorial Institute for Medical Research, University of Ghana, Legon, Ghana
| | | | - Michael Emch
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599 USA ,Department of Geography, University of North Carolina, Chapel Hill 220 E Cameron Ave, Chapel Hill, NC 27599 USA
| | - Jeffrey A. Bailey
- Department of Pathology and Laboratory Medicine, Brown University, 55 Claverick St, Rm 314B, Providence, RI 02912 USA
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Topazian HM, Gumbo A, Puerto-Meredith S, Njiko R, Mwanza A, Kayange M, Mwalilino D, Mvula B, Tegha G, Mvalo T, Edwards JK, Emch M, Pettifor A, Smith JS, Hoffman I, Meshnick SR, Juliano JJ. Asymptomatic Plasmodium falciparum malaria prevalence among adolescents and adults in Malawi, 2015-2016. Sci Rep 2020; 10:18740. [PMID: 33127922 PMCID: PMC7603306 DOI: 10.1038/s41598-020-75261-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 10/13/2020] [Indexed: 11/25/2022] Open
Abstract
Malaria remains a significant cause of morbidity and mortality in Malawi, with an estimated 18–19% prevalence of Plasmodium falciparum in children 2–10 years in 2015–2016. While children report the highest rates of clinical disease, adults are thought to be an important reservoir to sustained transmission due to persistent asymptomatic infection. The 2015–2016 Malawi Demographic and Health Survey was a nationally representative household survey which collected dried blood spots from 15,125 asymptomatic individuals ages 15–54 between October 2015 and February 2016. We performed quantitative polymerase chain reaction on 7,393 samples, detecting an overall P. falciparum prevalence of 31.1% (SE = 1.1). Most infections (55.6%) had parasitemias ≤ 10 parasites/µL. While 66.2% of individuals lived in a household that owned a bed net, only 36.6% reported sleeping under a long-lasting insecticide-treated net (LLIN) the previous night. Protective factors included urbanicity, greater wealth, higher education, and lower environmental temperatures. Living in a household with a bed net (prevalence difference 0.02, 95% CI − 0.02 to 0.05) and sleeping under an LLIN (0.01; − 0.02 to 0.04) were not protective against infection. Our findings demonstrate a higher parasite prevalence in adults than published estimates among children. Understanding the prevalence and distribution of asymptomatic infection is essential for targeted interventions.
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Affiliation(s)
- Hillary M Topazian
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, 27510, USA.
| | - Austin Gumbo
- National Malaria Control Programme, Malawi Ministry of Health, Lilongwe, Malawi
| | | | - Ruth Njiko
- University of North Carolina Project-Malawi, Lilongwe, Malawi
| | - Alexis Mwanza
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, 27510, USA
| | - Michael Kayange
- National Malaria Control Programme, Malawi Ministry of Health, Lilongwe, Malawi
| | - David Mwalilino
- National HIV Reference Laboratory, Malawi Ministry of Health, Lilongwe, Malawi
| | - Bernard Mvula
- National HIV Reference Laboratory, Malawi Ministry of Health, Lilongwe, Malawi
| | - Gerald Tegha
- University of North Carolina Project-Malawi, Lilongwe, Malawi
| | - Tisungane Mvalo
- University of North Carolina Project-Malawi, Lilongwe, Malawi.,Department of Pediatrics, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - Jessie K Edwards
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, 27510, USA
| | - Michael Emch
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, 27510, USA.,Department of Geography, University of North Carolina, Chapel Hill, NC, USA
| | - Audrey Pettifor
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, 27510, USA.,Carolina Population Center, University of North Carolina, Chapel Hill, NC, USA
| | - Jennifer S Smith
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, 27510, USA
| | - Irving Hoffman
- University of North Carolina Project-Malawi, Lilongwe, Malawi.,Institute for Global Health and Infectious Diseases, University of North Carolina, Chapel Hill, NC, USA
| | - Steven R Meshnick
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, 27510, USA
| | - Jonathan J Juliano
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC, USA
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Bell GJ, Loop MS, Mvalo T, Juliano JJ, Mofolo I, Kamthunzi P, Tegha G, Lievens M, Bailey J, Emch M, Hoffman I. Environmental modifiers of RTS,S/AS01 malaria vaccine efficacy in Lilongwe, Malawi. BMC Public Health 2020; 20:910. [PMID: 32532234 PMCID: PMC7291743 DOI: 10.1186/s12889-020-09039-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 06/03/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND RTS,S/AS01 is the first vaccine against malaria to undergo pilot implementation, beginning in 2019 and vaccinating 360,000 children per year in Malawi, Ghana, and Kenya. The four-dose vaccine is given as a primary three-dose series with a fourth dose given approximately 18 months later. The efficacy of RTS,S/AS01 was variable among the 11 sites participating in the 2009-2014 phase III trial (MALARIA-055, NCT00866619), possibly due to differences in transmission intensity. However, a within-site examination of environmental factors related to transmission intensity and their impact on vaccine efficacy has yet to be conducted. METHODS We implemented the phase III RTS,S/AS01 trial at the Malawi site, which enrolled 1578 infants (6-12 weeks) and children (5-17 months) living in the Lilongwe District in Central Malawi and followed them for 3 years between 2009 and 2014. A global positioning system survey and an ecological questionnaire were conducted to collect participant household locations and characteristics, while additional data on background malaria prevalence were obtained from a concurrent Malaria Transmission Intensity (MTI) survey. Negative binomial regression models were used to assess whether the efficacy of the vaccine varied by estimated background malaria prevalence, household roof type, or amount of nearby vegetation. RESULTS Vaccine efficacy did not significantly vary by estimated malaria prevalence or by roof type. However, increased vegetation cover was associated with an increase in the efficacy of the three-dose primary RTS,S/AS01 series in the 18 months before the fourth dose and a decrease in the efficacy of the primary vaccine series in the second 18 months following, if the fourth dose was not given. Vegetation cover did not alter the efficacy of the fourth dose in a statistically or practically significant manner. CONCLUSIONS Vegetation coverage in this study site might be a proxy for nearness to rivers or branching, shallow wetlands called "dambos" which could serve as breeding sites for mosquitoes. We observed statistically significant modification of the efficacy of RTS,S/AS01 by forest cover, suggesting that initial vaccine efficacy and the importance of the fourth dose varies based on ecological context. TRIAL REGISTRATION Efficacy of GSK Biologicals' Candidate Malaria Vaccine (257049) Against Malaria Disease Caused by P. falciparum Infection in Infants and Children in Africa. NCT00866619 prospectively registered 20 March 2009.
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Affiliation(s)
- Griffin J. Bell
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Matthew S. Loop
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Tisungane Mvalo
- University of North Carolina, Chapel Hill, NC 27599 USA
- University of North Carolina Project Malawi, Lilongwe, Malawi
| | - Jonathan J. Juliano
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Innocent Mofolo
- University of North Carolina, Chapel Hill, NC 27599 USA
- University of North Carolina Project Malawi, Lilongwe, Malawi
| | - Portia Kamthunzi
- University of North Carolina, Chapel Hill, NC 27599 USA
- University of North Carolina Project Malawi, Lilongwe, Malawi
| | - Gerald Tegha
- University of North Carolina Project Malawi, Lilongwe, Malawi
| | | | - Jeffrey Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI 02912 USA
| | - Michael Emch
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599 USA
| | - Irving Hoffman
- University of North Carolina, Chapel Hill, NC 27599 USA
- University of North Carolina Project Malawi, Lilongwe, Malawi
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Sarker AR, Sultana M. Cost-effective analysis of childhood malaria vaccination in endemic hotspots of Bangladesh. PLoS One 2020; 15:e0233902. [PMID: 32470101 PMCID: PMC7259743 DOI: 10.1371/journal.pone.0233902] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Accepted: 05/14/2020] [Indexed: 12/28/2022] Open
Abstract
INTRODUCTION Bangladesh has a history of endemic malaria transmission, with 17.5 million people at risk. The objective of this study was to assess the cost-effectiveness of universal childhood malaria vaccination in Chittagong Hill Tracts (CHT) of Bangladesh with newly developed RTS,S/AS01 malaria vaccines. METHODS A decision model was been developed using Microsoft® Excel to examine the potential impact of future vaccination in Bangladesh. We estimated the economic and health burden due to malaria and the cost-effectiveness of malaria vaccination from the health system and societal perspective. The primary outcomes include the incremental cost per Disability-Adjusted Life Year (DALY) averted, incremental cost per case averted, and the incremental cost per death averted. RESULTS Introducing childhood malaria vaccination in CHT in Bangladesh for a single birth cohort could prevent approximately 500 malaria cases and at least 30 deaths from malaria during the first year of vaccination. The cost per DALY averted of introducing the malaria vaccine compared to status quo is US$ 2,629 and US$ 2,583 from the health system and societal perspective, respectively. CONCLUSIONS Introduction of malaria vaccination in CHT region is estimated to be a cost-effective preventive intervention and would offer substantial future benefits particularly for young children vaccinated today. Policies should, thus, consider the operational advantages of targeting these populations, particularly in the CHT area, with the vaccine along with other malaria control initiatives.
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Affiliation(s)
- Abdur Razzaque Sarker
- Population Studies Division, Bangladesh Institute of Development Studies (BIDS), Dhaka, Bangladesh
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
| | - Marufa Sultana
- International Centre for Diarrhoeal Disease Research, Bangladesh (icddr,b), Dhaka, Bangladesh
- School of Health and Social Development, Deakin University, Burwood, Melbourne, Australia
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Bell GJ, Loop M, Topazian HM, Hudgens M, Mvalo T, Juliano JJ, Kamthunzi P, Tegha G, Mofolo I, Hoffman I, Bailey JA, Emch M. Case reduction and cost-effectiveness of the RTS,S/AS01 malaria vaccine alongside bed nets in Lilongwe, Malawi. Vaccine 2020; 38:4079-4087. [PMID: 32362527 DOI: 10.1016/j.vaccine.2020.04.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 04/10/2020] [Accepted: 04/13/2020] [Indexed: 01/22/2023]
Abstract
BACKGROUND RTS,S/AS01, the most advanced vaccine against malaria, is now undergoing pilot implementation in Malawi, Ghana, and Kenya where an estimated 360,000 children will be vaccinated each year. In this study we evaluate RTS,S/AS01 alongside bed net use and estimate cost-effectiveness. METHODS RTS,S/AS01 phase III trial and bed net prevalence data were used to determine the effect of vaccination in the urban/periurban and rural areas of Lilongwe, Malawi. Cost data were used to calculate the cost-effectiveness of various interventions over three years. FINDINGS Since bed nets reduce malaria incidence and homogeneous vaccine efficacy was assumed, participants without bed nets received greater relative benefit from vaccination with RTS,S/AS01 than participants with bed nets. Similarly, since malaria incidence in rural Lilongwe is higher than in urban Lilongwe, the impact and cost-effectiveness of vaccine interventions is increased in rural areas. In rural Lilongwe, we estimated that vaccinating one child without a bed net would prevent 2·59 (1·62 to 3·38) cases of malaria over three years, corresponding to a cost of $10·08 (7·71 to 16·13) per case averted. Alternatively, vaccinating one child with a bed net would prevent 1·59 (0·87 to 2·57) cases, corresponding to $16·43 (10·16 to 30·06) per case averted. Providing RTS,S/AS01 to 30,000 children in rural Lilongwe was estimated to cost $782,400 and to prevent 58,611 (35,778 to 82,932) cases of malaria over a three-year period. Joint interventions providing both vaccination and bed nets (to those without them) were estimated to prevent additional cases of malaria and to be similarly cost-effective, compared to vaccine-only interventions. INTERPRETATION To maximize malaria prevention, vaccination and bed net distribution programs could be integrated. FUNDING Impacts of Environment, Host Genetics and Antigen Diversity on Malaria Vaccine Efficacy (1R01AI137410-01).
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Affiliation(s)
- Griffin J Bell
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Matthew Loop
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Hillary M Topazian
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Michael Hudgens
- Department of Biostatistics, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Tisungane Mvalo
- University of North Carolina, Chapel Hill, NC 27599, USA; University of North Carolina Project, Lilongwe, Malawi.
| | - Jonathan J Juliano
- Division of Infectious Diseases, School of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA.
| | - Portia Kamthunzi
- University of North Carolina, Chapel Hill, NC 27599, USA; University of North Carolina Project, Lilongwe, Malawi.
| | - Gerald Tegha
- University of North Carolina Project, Lilongwe, Malawi.
| | - Innocent Mofolo
- University of North Carolina, Chapel Hill, NC 27599, USA; University of North Carolina Project, Lilongwe, Malawi.
| | - Irving Hoffman
- University of North Carolina, Chapel Hill, NC 27599, USA; University of North Carolina Project, Lilongwe, Malawi.
| | - Jeffrey A Bailey
- Department of Pathology and Laboratory Medicine, Brown University, Providence, RI 02903, USA
| | - Michael Emch
- Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, NC 27599, USA.
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Pasin C, Halloran ME, Gilbert PB, Langevin E, Ochiai RL, Pitisuttithum P, Capeding MR, Carrasquilla G, Frago C, Cortés M, Chambonneau L, Moodie Z. Periods of high dengue transmission defined by rainfall do not impact efficacy of dengue vaccine in regions of endemic disease. PLoS One 2018; 13:e0207878. [PMID: 30543657 PMCID: PMC6292612 DOI: 10.1371/journal.pone.0207878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Accepted: 11/07/2018] [Indexed: 11/22/2022] Open
Abstract
OBJECTIVE To evaluate the association of rainy season with overall dengue disease incidence and with the efficacy of the Sanofi Pasteur recombinant, live, attenuated, tetravalent vaccine (CYD-TDV) in two randomized, controlled multicenter phase III clinical trials in Asia and Latin America. METHODS Rainy seasons were defined for each study site using climatological information from the World Meteorological Organization. The dengue attack rate in the placebo group for each study month was calculated as the number of symptomatic, virologically-confirmed dengue events in a given month divided by the number of participants at risk in the same month. Time-dependent Cox proportional hazard models were used to test whether rainy season was associated with dengue disease and whether it modified vaccine efficacy in each of the two trials and in both of the trials combined. FINDINGS Rainy season, country, and age were all significantly associated with dengue disease in both studies. Vaccine efficacy did not change during the rainy season in any of the analyses. CONCLUSIONS Although dengue transmission and exposure are expected to increase during the rainy season, our results indicate that CYD-TDV vaccine efficacy remains constant throughout the year in endemic regions.
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Affiliation(s)
- Chloé Pasin
- Université de Bordeaux, INSERM U1219 Bordeaux Population Health center, INRIA SISTM, Bordeaux, France
- Vaccine Research Institute, Creteil, France
- ENS Cachan, Université Paris-Saclay, Cachan, France
| | - M. Elizabeth Halloran
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- University of Washington, Seattle, Washington, United States of America
| | - Peter B. Gilbert
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
- University of Washington, Seattle, Washington, United States of America
| | | | | | - Punnee Pitisuttithum
- Vaccine Trial Centre and Department of Clinical Tropical Medicine, Faculty of Tropical Medicine, Mahidol University, Nakorn Pratum, Thailand
| | | | | | | | | | | | - Zoe Moodie
- Fred Hutchinson Cancer Research Center, Seattle, Washington, United States of America
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12
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Ubillos I, Ayestaran A, Nhabomba AJ, Dosoo D, Vidal M, Jiménez A, Jairoce C, Sanz H, Aguilar R, Williams NA, Díez-Padrisa N, Mpina M, Sorgho H, Agnandji ST, Kariuki S, Mordmüller B, Daubenberger C, Asante KP, Owusu-Agyei S, Sacarlal J, Aide P, Aponte JJ, Dutta S, Gyan B, Campo JJ, Valim C, Moncunill G, Dobaño C. Baseline exposure, antibody subclass, and hepatitis B response differentially affect malaria protective immunity following RTS,S/AS01E vaccination in African children. BMC Med 2018; 16:197. [PMID: 30376866 PMCID: PMC6208122 DOI: 10.1186/s12916-018-1186-4] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Accepted: 10/01/2018] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The RTS,S/AS01E vaccine provides partial protection against malaria in African children, but immune responses have only been partially characterized and do not reliably predict protective efficacy. We aimed to evaluate comprehensively the immunogenicity of the vaccine at peak response, the factors affecting it, and the antibodies associated with protection against clinical malaria in young African children participating in the multicenter phase 3 trial for licensure. METHODS We measured total IgM, IgG, and IgG1-4 subclass antibodies to three constructs of the Plasmodium falciparum circumsporozoite protein (CSP) and hepatitis B surface antigen (HBsAg) that are part of the RTS,S vaccine, by quantitative suspension array technology. Plasma and serum samples were analyzed in 195 infants and children from two sites in Ghana (Kintampo) and Mozambique (Manhiça) with different transmission intensities using a case-control study design. We applied regression models and machine learning techniques to analyze immunogenicity, correlates of protection, and factors affecting them. RESULTS RTS,S/AS01E induced IgM and IgG, predominantly IgG1 and IgG3, but also IgG2 and IgG4, subclass responses. Age, site, previous malaria episodes, and baseline characteristics including antibodies to CSP and other antigens reflecting malaria exposure and maternal IgGs, nutritional status, and hemoglobin concentration, significantly affected vaccine immunogenicity. We identified distinct signatures of malaria protection and risk in RTS,S/AS01E but not in comparator vaccinees. IgG2 and IgG4 responses to RTS,S antigens post-vaccination, and anti-CSP and anti-P. falciparum antibody levels pre-vaccination, were associated with malaria risk over 1-year follow-up. In contrast, antibody responses to HBsAg (all isotypes, subclasses, and timepoints) and post-vaccination IgG1 and IgG3 to CSP C-terminus and NANP were associated with protection. Age and site affected the relative contribution of responses in the correlates identified. CONCLUSIONS Cytophilic IgG responses to the C-terminal and NANP repeat regions of CSP and anti-HBsAg antibodies induced by RTS,S/AS01E vaccination were associated with malaria protection. In contrast, higher malaria exposure at baseline and non-cytophilic IgG responses to CSP were associated with disease risk. Data provide new correlates of vaccine success and failure in African children and reveal key insights into the mode of action that can guide development of more efficacious next-generation vaccines.
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Affiliation(s)
- Itziar Ubillos
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Aintzane Ayestaran
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Augusto J Nhabomba
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - David Dosoo
- Kintampo Health Research Centre, Kintampo, Ghana
| | - Marta Vidal
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Alfons Jiménez
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Spanish Consortium for Research in Epidemiology and Public Health (CIBERESP), Barcelona, Spain
| | - Chenjerai Jairoce
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Hèctor Sanz
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Ruth Aguilar
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Nana Aba Williams
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Núria Díez-Padrisa
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain
| | - Maximilian Mpina
- Ifakara Health Institute, Bagamoyo Research and Training Center, P.O. Box 74, Bagamoyo, Tanzania
| | - Hermann Sorgho
- Institut de Recherche en Sciences de la Santé, Nanoro, Burkina Faso
| | - Selidji Todagbe Agnandji
- Centre de Recherches Médicales de Lambaréné (CERMEL), BP 242, Lambaréné, Gabon.,Institute of Tropical Medicine and German Center for Infection Research, University of Tübingen, Wilhelmstraße 27, 72074, Tübingen, Germany
| | - Simon Kariuki
- Kenya Medical Research Institute (KEMRI)/Centre for Global Health Research, Kisumu, Kenya
| | - Benjamin Mordmüller
- Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
| | - Claudia Daubenberger
- Ifakara Health Institute, Bagamoyo Research and Training Center, P.O. Box 74, Bagamoyo, Tanzania.,Swiss Tropical and Public Health Institute, Socinstrasse 57, 4002, Basel, Switzerland
| | | | | | - Jahit Sacarlal
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique.,Facultade de Medicina, Universidade Eduardo Mondlane, Maputo, Mozambique
| | - Pedro Aide
- Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - John J Aponte
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Sheetij Dutta
- Walter Reed Army Institute of Research (WRAIR), Silver Spring, MD, USA
| | - Ben Gyan
- Kintampo Health Research Centre, Kintampo, Ghana.,Noguchi Memorial Institute for Medical Research, University of Ghana, Accra, Ghana
| | - Joseph J Campo
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Clarissa Valim
- Department of Osteopathic Medical Specialties, Michigan State University, 909 Fee Road, Room B 309 West Fee Hall, East Lansing, MI, 48824, USA.,Department of Immunology and Infectious Diseases, Harvard T.H. Chen School of Public Health, 675 Huntington Ave., Boston, MA, 02115, USA
| | - Gemma Moncunill
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain.,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique
| | - Carlota Dobaño
- ISGlobal, Hospital Clínic, Universitat de Barcelona, Carrer Rosselló 153 CEK building, E-08036, Barcelona, Catalonia, Spain. .,Centro de Investigação em Saúde de Manhiça (CISM), Rua 12, Cambeve, Vila de Manhiça, CP 1929, Maputo, Mozambique.
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