A candidate malaria vaccine has produced disappointing results, showing lower efficacy in young babies than it does in older infants, the latest trial data show.

The efficacy of the vaccine RTS,S/AS01 in infants aged 6-12 weeks against clinical and severe malaria was 31% and 37%, respectively, found the study, published in the New England Journal of Medicine.1 Last year phase 1 clinical trials of the same vaccine in infants aged 5-17 months showed an efficacy rate of 56% for clinical malaria and 47% for severe malaria.2

Salim Abdulla, principal investigator in the trial, which is being conducted by a partnership between the drug firm GlaxoSmithKline, the Malaria Vaccine Initiative, and 11 African research centres, said that the study showed the …