Abstracts

Prototype malaria vaccine doesn’t work for children in Mali

GlaxoSmithKline’s latest malaria vaccine failed to prevent clinical disease in a recent trial in Mali. Children given three doses at monthly intervals mounted a good immune response, but an estimated 48.4% still developed clinical falciparum malaria over the next six months. A comparable proportion of controls, who were given a rabies vaccine, also developed clinical malaria (54.4%; hazard ratio 0.83, 95% confidence interval (CI) 0.63 - 1.09). Four hundred children aged 1 - 6 years took part.

The authors were testing a monovalent prototype directed against the blood stage of the falciparum malaria parasite. The active ingredient (antigen) is a membrane protein called apical membrane antigen 1, from the 3D7 strain of Plasmodium falciparum. Although the children in this trial didn’t get any useful protection from malaria in general, the vaccine did seem to protect them from the 3D7 strain. Of the 22 children with this infection, 16 were in the control group, which gives an estimated efficacy of 64.3% (0.36, 0.08 - 0.86).

Fevers were significantly more common after the malaria vaccine, and a local reaction was almost universal. Parents also reported more irritability, fussiness, and loss of appetite in children given the malaria vaccine. The authors say the safety profile looks acceptable so far, and they hope that FMP2.1/AS02A might eventually prove useful as part of a multicomponent vaccine.

Thera MA, et al. N Engl J Med 2011;365:1004-1013.

Bridget Farham