The Impact RTS,S/AS01 Vaccine in School Aged Children RTS,S/AS01 Malaria Vaccine in School Aged Children

Overview

Across sub-Saharan Africa, school-age children bear an under-appreciated burden of malaria. An estimated 200 million school-age children are at risk of malaria and in many areas prevalence of infection exceeds 50%. The high infection rates in this group serves as a source of onward parasite transmission, undermining elimination and control efforts. Furthermore, malaria illness and malaria-induced anemia in this age group lead to school absenteeism, and impaired cognitive function and classroom attention, ultimately resulting in reduced academic achievement. Although universal malaria interventions, such as insecticide treated nets (ITNs) and access to prompt diagnosis and treatment are available to school-age children, this age group is the least likely to benefit from these interventions. Furthermore, efficacy of these approaches may be compromised by increasing anti-malarial drug and insecticide resistance. A malaria vaccine could help to avert the burden of malaria in this age group. The RTS,S/AS01 malaria vaccine has recently been recommended for vaccination of young children (\< 24 months) by the World health organization (WHO) after a Phase 3 trial and an implementation trial showed that the vaccine had moderate but significant efficacy to prevent clinical and severe malaria in young children. Previous randomized trials suggest that the vaccine is safe for older children. However, efficacy of the vaccine has never been assessed in school age children. Kamuzu University of Health Sciences in partnership with the Malawian Ministry of Health seeks to evaluate the efficacy of the newly introduced RTSS/AS01 malaria vaccine in school aged children. The study hypothesizes that vaccination will decrease the morbidity and transmission of malaria, as well as improve school absenteeism and educational outcomes.

This study will be an individual randomized open-label clinical trial to assess the impact, feasibility, acceptability and cost effectiveness of the RTS,S/AS01 vaccine in school-aged children in a malaria endemic environment. A total of 5400 children aged 6 to 15 years who are attending standards 1-8 in five schools in rural (Machinga) district of Malawi will be randomized to one of the four intervention arms: RTS,S/AS01 vaccine only (RTS,S-only), RTS,S/AS01 vaccine plus an effective antimalarial (artemether-lumefantrine) at the start of the study (RTS,S+AL), artemether-lumefantrine only (AL-only) and a control group that receives only Vitamin A at the start of the study (VIT-A). After obtaining consent from guardians and assent from children older than 13 years of age, participating children will be randomly allocated in a 1:1:1:1 ratio into the intervention arms. Randomization will be stratified by classroom and school. Additionally, two siblings of a subset of 1000 children receiving the vaccine will be enrolled to evaluate the indirect effect of vaccination. All children will be followed for up to 12 months after vaccination. Clinical malaria will be ascertained through passive case detection (PCD), and attendance and education outcomes will be ascertained through school records. PCD will conducted using the Learner Treatment Kit program platform, a school-based malaria diagnosis and treatment program that the Ministry of Health and Education are currently supporting across the selected schools. Through PCD, the safety of the interventions will also be monitored. In a subset of 1000 enrolled in the study (250 per intervention arm) and two of their siblings will also be followed in three pre-scheduled visits, the active case detection (ACD) cohort in which the investigators will evaluate outcomes including the direct effect of the vaccine on malaria subclinical infection and the indirect effect of the vaccine. Children will be selected for this cohort randomly, stratifying the samples by school and four age strata (6-7 years, 8-9 years, 10-12 years, 13-15 years). Participants will be invited to visit a health center at baseline, i.e., before the interventions are administered, one month, six months, and 12 months after the end of the primary regimen of RTS,S/AS01. At each of these visits, capillary blood (\~500 µl) will be collected through finger pricks for a dry blood spot, from which malaria quantitative polymerase chain reactions (qPCRs) will be performed to detect asexual parasites. In addition, one drop of blood will be used to measure hemoglobin concentrations. The remaining blood will be stored In 500 children enrolled in the ACD cohort and receiving vaccination, 6 mL of venous blood will be collected to evaluate immunological outcomes. These children will be randomly selected among those receiving RTS, S/AS01 (200 RTSS+AL and 200 RTSS-only) in four schools (50 X 2 intervention groups in each school), and the 4 age strata (\~ 12 per age strata in each school and intervention group). Feasibility, acceptability and cost data will be collected through interviews with all study stakeholders: learners, parents, teachers, community leaders, and district and national policy makers.