Last Updated: 25/02/2026
A phase III, double-blind (observer-blind), randomized, controlled multi-centre study to evaluate, in infants and children, the efficacy of the RTS,S/AS01E candidate vaccine against malaria disease caused by Plasmodium falciparum infection across diverse malaria transmission settings in Africa (MAL055)
Objectives
The main objectives of the MAL055 phase III study were to continue evaluating the safety, efficacy, and immunogenicity of the candidate vaccine in different conditions of malaria transmission. Favorable results will result in licensing in the near future.
Specifically:
- To address key gaps in knowledge of RTS,S mode of action through the analysis of well-characterized plasma and cell samples collected in the African multi-center pediatric Phase 3 trial.
- To characterize the quality of the antibody response and supporting B and T helper cells (TFH-like and TH2), as well as TH1 responses that may contribute to protection via effector functions such as cytolytic killing of parasite-infected erythrocytes or secretion of cytokines.
In 2009 RTS,S was the most advanced malaria vaccine candidate and the first to demonstrate in clinical trials that it can protect young children living in malaria endemic areas against infection and clinical disease caused by Plasmodium falciparum. This vaccine was created in 1987 by GlaxoSmithKline, and CRESIB has been working with the Centro de Investigação em Saúde de Manhiça (CISM) since 2002 in the clinical development of the vaccine, in collaboration with the PATH Malaria Vaccine Initiative (MVI) and GlaxoSmithKline Biologicals (GSK).
In 2003, the first phase IIb trial in Mozambican children aged 1 to 4 years old was initiated and has proven that RTS,S reduces the incidence of clinical malaria episodes (35.3%) and severe malaria (48.6%) for a period of 18 months post vaccination. CRESIB and CISM carried out the first I/IIb clinical trials in infants to evaluate safety, efficacy and immunogenicity. The results were published in 2007, proving that the vaccine is safe, well-tolerated and efficacious against new infections (65.9%) in this age group.
In May 2009 GSK, PATH MVI and 11 leading African research centres launched a phase III trial of GSK’s RTS,S malaria vaccine candidate, known as the MAL055 study, in Mozambique and six other African countries, with an enrolment target of 16,000 children and infants.
Phase III, double-blind (observer-blind), randomized, controlled multi-centre study to evaluate, in infants and children, the efficacy of the RTS,S/AS01E candidate vaccine against malaria disease.
Primary Purpose: Prevention
Allocation: Randomized
Interventional Model: Parallel Assignment
Masking: Quadruple (ParticipantCare ProviderInvestigatorOutcomes Assessor)
* Official Title: Efficacy of GSK Biologicals’ Candidate Malaria Vaccine (257049) Against Malaria Disease Caused by P. Falciparum Infection in Infants and Children in Africa
Sep 2009 — Dec 2015
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