Young African children may be protected from malaria for at least 15 months after vaccination
WEDNESDAY, Jan. 19 (HealthDay News) -- The lead candidate malaria vaccine, RTS,S/AS01E, offers long-lasting protection against clinical malaria in healthy African children, according to a study published online Jan. 14 in The Lancet Infectious Diseases.
Ally Olotu, M.D., from the Kenya Medical Research Institue-Wellcome Trust Research Programme in Kilifi, and colleagues evaluated the efficacy of the RTS,S/AS01E vaccine against Plasmodium falciparum in 5- to 17-month-old children. Between March 2007 and October 2008, 894 children from Kenya and Tanzania were randomly assigned to three doses of either RTS,S/AS01E or rabies vaccine, and were followed up for a minimum of 12 months. Blood samples were taken before vaccination and at regular intervals during the trial to measure antibody titres. The study end point was the time to the first clinical malaria episode, characterized by fever and Plasmodium falciparum density of 2500/µL or more.
The study team found the vaccine efficacy in the first 12 months to be 39.2 percent in the per-protocol analysis. At 15 months after vaccination, children vaccinated with RTS,S/AS01E were 45.8 percent less likely to have had a first or only clinical malaria episode. Antibody titres at one month after the third dose were not associated with protection from malaria, but they were at 6.5 months.
"RTS,S/AS01E provides sustained protection from clinical malaria over a period of 15 months (range 12 to 18 months) in young children residing in malaria endemic areas," the authors write.
GlaxoSmithKline provided funding for the study. Several of the study authors disclosed financial ties with pharmaceutical companies.
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