The RTS,S malaria vaccine

The initial results of the phase III clinical trial for RTS,S—currently the leading malaria vaccine candidate—were recently announced,1 amid international media coverage suggesting that the vaccine could avert millions of deaths and bring the eradication of malaria closer.2 3 The large well conducted multicentre trial showed a 50% reduction in the incidence of malaria among young children.1 This is broadly in line with initial phase II data, although hopes raised by the earlier (smaller) study that it might be even more effective in severe cases were not confirmed.4 5

This is undoubtedly a major scientific achievement, and is the first vaccine against a human parasite that has appreciable clinical effects. Malaria still kills more than 700 000 children in Africa6—the target population for this vaccine—and reduces the life chances of many more. Scientists involved in the development and testing of this vaccine should be justifiably proud of their achievement. RTS,S incorporates hepatitis B surface antigens and it also induces good immunity to hepatitis B.7

The future impact of this vaccine—which is likely to be licensed by the end of 2015—on public health is however more difficult to assess. Although these are only …