Malaria Vaccine Does Not Protect Against Clinical Malaria
But is strain specific for clinical malaria caused by parasites with the AMA1 DNA sequence
WEDNESDAY, Sept. 14 (HealthDay News) -- The malaria vaccine, FMP 2.1/AS02A, based on apical membrane antigen 1 (AMA1) from the 3D7 strain of Plasmodium falciparum does not provide significant protection against clinical malaria, but may have strain-specific efficacy against parasites with AMA1 corresponding to that of the vaccine strain, according to a study published in the Sept. 15 issue of the New England Journal of Medicine.
Mahamadou A. Thera, M.D., M.P.H., from the University of Bamako in Mali, and colleagues investigated the efficacy of FMP 2.1/AS02A against clinical falciparum malaria in Malian children and sought to determine whether the efficacy was strain specific. A total of 400 Malian children were immunized with either the malaria vaccine or a control (rabies) vaccine, and followed up for six months. Clinical malaria and clinical malaria caused by parasites with the AMA1 DNA sequence found in the vaccine strain were the primary and secondary end points, respectively.
The investigators found that the cumulative incidence for the primary end point in the malaria-vaccine and control group was 48.4 and 54.4 percent, respectively, with 17.4 percent efficacy against the primary end point (hazard ratio [HR], 0.83; P = 0.18). The vaccine had an efficacy of approximately 20 percent against the first and subsequent episodes of clinical malaria. An efficacy of 64.3 percent was observed against clinical malaria caused by parasites with AMA1 corresponding to that of the vaccine strain (HR, 0.36). Fever after vaccination and local reactions were frequent with the malaria vaccine.
"On the basis of the primary end point, the malaria vaccine did not provide significant protection against clinical malaria, but on the basis of secondary results, it may have strain-specific efficacy," the authors write.
Several authors disclosed financial relationships with GlaxoSmithKline Biologicals.