A clinical trial on the vaccine, RTS,S, showed that it is doesn't have the protective effects that everyone is claiming, and whatever protection it does offer appears to weaken over time.
Malaria experts have reckoned that an effective vaccine must offer in excess of a 50 per cent level of protection, but RTS,S falls short. In infants aged between six to 12 weeks, it has a protective effect of 27 per cent just 18 months after vaccination, while it gave children aged between five and 17 months at the time of vaccination a 46 per cent reduced risk of malaria. The worrying aspect of the data is that any protection diminishes with time.
After 12 months, the protective effect in the two age groups was 56 per cent and 31 per cent respectively.
Although it was simple to win over the media, critics fear the European Medicines Agency and the World Health Organization (WHO) might not be so easily impressed.
(Source: The Economist, October 8, 2013)