A vast phase III clinical trial in Africa of the malaria vaccine candidate RTS,S/AS01 reported disappointing results this morning. The vaccine failed to show substantial protection in the key trial age group of infants who received their first shot between 6 and 12 weeks of age. The low protective effect of the vaccine was around half that reported last year in older children in the same study, and that of an earlier, smaller trial of babies of the same age group.
Work on the RTS,S vaccine began a quarter of a century ago within the US military, with development since 2001 being carried out by a public–private venture between the PATH Malaria Vaccine Initiative (MVI) – supported by US$200 million from the Bill & Melinda Gates Foundation in Seattle, Washington – and the London-based pharmaceutical company GlaxoSmithKline (GSK). Eleven research centres in seven African countries are involved in organizing the phase III trial, which involves vaccinating and monitoring thousands of children.