Malaria remains a major public health problem in most tropical coun- tries. Plasmodium falciparum
infection can be life-threatening, especially in children.
Insecticide-treated bed nets have been shown to reduce deaths due to
malaria among young children. A
malaria vaccine (
RTS,S/AS01E) containing two adjuvants has been assessed for its ability to prevent P.
falciparum malaria among young children living in endemic areas. The clinical data have been analysed by the European Medicines Agency (EMA) in conjunction with the World Health Organization (WHO). Efficacy has been evaluated in sub-Saharan African countries. Two trials including a total of more than 16 000 children aged 6 weeks to 17 months compared the
malaria vac- cine with a
rabies vaccine or a menin- gococcal
vaccine. Most of the children were healthy, had ready access to healthcare, and were protected with bed nets. In these trials, three
injections of the
malaria vaccine one month apart did not reduce overall mortality or
malaria mortality in low-mortality settings. In the year following vaccina- tion, the risk of
malaria episodes was reduced by about 30% among children aged 6 to 12 weeks and by about 50% among those aged 5 to 17 months.The incidence of severe
malaria was only reduced in the older age group. Vac- cine efficacy waned rapidly over time, even with a booster dose at 18 months. During clinical trials, reactions at the injection site and systemic reac- tions were more frequent with the
malaria vaccine than with the compara- tor
vaccines.
Febrile seizures during the days following vaccination were 2 to 5 times more frequent with the
malaria vaccine among children aged 5 to 17 months. The
malaria vaccine may also carry a risk of
meningitis, as well as a risk of
pneumonia among HIV-infected children and premature infants.