Malaria

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Browsing Malaria by Author "Mathanga, Don"

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    Strengthening the evidence on the RTS,S/AS01 malaria vaccine: assessment of safety and effectiveness using case-control studies
    (Kamuzu University of Health Sciences, 2021-05-26) Mathanga, Don
    Problem statement: Malaria remains a major cause of childhood morbidity and mortality, particularly in sub-Saharan Africa, where over 90% of all cases occur. In 2018, 228 million malaria cases and 405 000 deaths were estimated worldwide, with the majority of deaths in African children. New tools are urgently needed to change the trajectory of malaria morbidity and mortality and the RTS,S/AS01 (RTS,S) malaria vaccine currently being piloted in 3 countries including Malawi is the first and only vaccine that has been shown to provide protection against malaria. Recent review of data on the RTS,S vaccine, including long term follow-up, brought into question the necessity of the 4th dose. Additionally, data generated from the MVPE show lower than expected event rates for the safety outcomes of interest such as cerebral malaria and meningitis. The Malaria Vaccine Implementation Programme Advisory group therefore recommened that a case-control study should complement data being collected through surveys and cohort studies to comperehesively address questions on vaccine safety. Objectives: The overall objectives of the case-control study is to determine the association of the RTS,S vaccine with the safety signals identified in the Phase 3 trial of RTS,S. The specific objectives include:: To determine if children who receive RTS,S vaccination (at least one dose) are at increased risk of meningitis compared to unvaccinated children. To determine if children who receive RTS,S vaccine (at least one dose), or children who receive 3 doses, are at increased risk of cerebral malaria compared to unvaccinated children. To estimate the incidence of severe malaria in children who received 3 doses, but failed to receive a 4th dose, compared to children who did not receive the vaccine (the rebound effect). To determine the effectiveness of RTS,S (following 3 doses and following the 4th dose) in preventing severe malaria. To assess if RTS,S vaccine increase mortality in girls, or is less effective in preventing deaths in girls than in boys. Type of research study: Case control Study. Methods: The sites of the study are Balaka and Machinga, Ntchisi and Mchinji districts. Cases will be children with either confirmed meningitis, or severe malaria or who die. For each case, four control children born within one month of the date of birth of the case will be recruited from the neighbourhood of the case’s home, after moving a distance of at least 100m from the home of the case. The case will be visited at home, to confirm details recorded in hospital and to collect further information about the case and their household. Then the same field team will recruit controls from the same neighbourhood. Controls for deaths will be recruited following completion of the verbal autopsy (VA), the VA team will then recruit controls from the same neighbourhood where the case child was living. Expected findings and their dissemination: Findings will provide important evidence to inform policy guidelines and clinical practice at the global level. A finding that a 3-dose regimen is sufficiently effective (and the 4th dose provided at 2 years of age unnecessary) would result in improved cost effectiveness and improved adherence. The results will be shared with stakeholders including the Ministry of Health, the World Health Organization and the global community through reports, local and international meetings and through peer reviewed publicactions.
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    Strengthening the evidence on the RTS,S/AS01 malaria vaccine: assessment of safety and effectiveness using case-control studies
    (Kamuzu University of Health Sciences, 2021-05-26) Mathanga, Don
    Problem statement: Malaria remains a major cause of childhood morbidity and mortality, particularly in sub-Saharan Africa, where over 90% of all cases occur. In 2018, 228 million malaria cases and 405 000 deaths were estimated worldwide, with the majority of deaths in African children. New tools are urgently needed to change the trajectory of malaria morbidity and mortality and the RTS,S/AS01 (RTS,S) malaria vaccine currently being piloted in 3 countries including Malawi is the first and only vaccine that has been shown to provide protection against malaria. Recent review of data on the RTS,S vaccine, including long term follow-up, brought into question the necessity of the 4th dose. Additionally, data generated from the MVPE show lower than expected event rates for the safety outcomes of interest such as cerebral malaria and meningitis. The Malaria Vaccine Implementation Programme Advisory group therefore recommened that a case-control study should complement data being collected through surveys and cohort studies to comperehesively address questions on vaccine safety. Objectives: The overall objectives of the case-control study is to determine the association of the RTS,S vaccine with the safety signals identified in the Phase 3 trial of RTS,S. The specific objectives include:  To determine if children who receive RTS,S vaccination (at least one dose) are at increased risk of meningitis compared to unvaccinated children.  To determine if children who receive RTS,S vaccine (at least one dose), or children who receive 3 doses, are at increased risk of cerebral malaria compared to unvaccinated children.  To estimate the incidence of severe malaria in children who received 3 doses, but failed to receive a 4th dose, compared to children who did not receive the vaccine (the rebound effect).  To determine the effectiveness of RTS,S (following 3 doses and following the 4th dose) in preventing severe malaria.  To assess if RTS,S vaccine increase mortality in girls, or is less effective in preventing deaths in girls than in boys. Type of research study: Case control Study. Methods: The sites of the study are Balaka and Machinga, Ntchisi and Mchinji districts. Cases will be children with either confirmed meningitis, or severe malaria or who die. For each case, four control children born within one month of the date of birth of the case will be recruited from the neighbourhood of the case’s home, after moving a distance of at least 100m from the home of the case. The case will be visited at home, to confirm details recorded in hospital and to collect further information about the case and their household. Then the same field team will recruit controls from the same neighbourhood. Controls for deaths will be recruited following completion of the verbal autopsy (VA), the VA team will then recruit controls from the same neighbourhood where the case child was living.Expected findings and their dissemination: Findings will provide important evidence to inform policy guidelines and clinical practice at the global level. A finding that a 3-dose regimen is sufficiently effective (and the 4th dose provided at 2 years of age unnecessary) would result in improved cost effectiveness and improved adherence. The results will be shared with stakeholders including the Ministry of Health, the World Health Organization and the global community through reports, local and international meetings and through peer reviewed publications.