NCT03281291

Study to Assess the Vaccine Efficacy Against Malaria Infection, in Children Immunized With the Primary and Yearly Booster of the RTS,S/AS01E Vaccine, as Part of Their Participation in the Malaria-094 (204889/NCT03276962) Study.

Molecular Detection and Genotyping of Plasmodium Falciparum Parasites in Young African Children After Immunization With RTS,S/AS01E Malaria Vaccine. An Ancillary Study Protocol to GlaxoSmithKline Phase IIb RTS,S/AS01E Malaria Vaccine Trial (Study Number 204889) Entitled, "Efficacy, Safety and Immunogenicity Study of GSK Biologicals' Candidate Malaria Vaccine (SB257049) Evaluating Schedules With or Without Fractional Doses, Early Dose 4 and Yearly Doses, in Children 5-17 Months of Age.

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 1,500 (actual)
• Sponsor: GlaxoSmithKline · Industry
• Sex: All
• Age: 5 Months – 17 Months
• Healthy volunteers: Accepted

Summary

The aim of this study was to evaluate the effectiveness of the RTS,S/AS01E malaria vaccine against both clinical and asymptomatic malaria infections by detecting Plasmodium falciparum (P. falciparum) parasites in blood samples collected from children who received the primary and yearly booster doses of the RTS,S/AS01E vaccine, as part of their participation in the Malaria-094 parent clinical study. The genomic analysis was conducted on parasites found in blood spot samples from children aged 5-17 months, who were vaccinated according to different dosage and schedule regimens as part of the Malaria-094 parent clinical study.

Detailed description

This genotyping study of malaria parasites, collected from serial blood samples following RTS,S/AS01E immunization, assessed vaccine efficacy using molecular genetic data. The study aimed to identify the first infections post-vaccination and distinguish new infections from existing ones through an amplicon sequencing-based strategy. This involved deep sequencing of small, highly variable regions of the parasite genome, enabling both: 1. Highly sensitive detection of parasitemia (similar to conventional polymerase chain reaction \[PCR\]-based detection), and 2. Identification of genetically distinct parasite populations within or between affected individuals.

Conditions

• Malaria

Timeline

• Start date: 2018-11-19
• Primary completion: 2022-04-22
• Completion: 2023-10-23
• First posted: 2017-09-13
• Last updated: 2025-01-23
• Results posted: 2025-01-23

Locations

2 sites across 2 countries: Ghana, Kenya