Vaccines for preventing malaria (SPf66).
BACKGROUND
A malaria vaccine is badly needed. SPf66 was one of the earliest vaccines developed. It is a synthetic peptide vaccine containing antigens from the blood stages of malaria linked together with an antigen from the sporozoite stage, and is targeted mainly against the blood (asexual) stages.


OBJECTIVE
To assess the effect of SPf66 malaria vaccines against Plasmodium falciparum, P. vivax, P. malariae, and P. ovale in preventing infection, disease, and death.


METHODS
We searched the Cochrane Infectious Diseases Group Specialized Register (September 2005), CENTRAL (The Cochrane Library 2005, Issue 3), MEDLINE (1966 to September 2005), EMBASE (1980 to September 2005), LILACS (1982 to September 2005), Science Citation Index (1981 to September 2005), and reference lists of articles. We also contacted organizations and researchers in the field.


METHODS
Randomized and quasi-randomized controlled trials comparing SPf66 vaccine with placebo or routine antimalarial control measures in people of any age receiving an artificial challenge or natural exposure to malaria infection (any species).


METHODS
Two people independently assessed trial quality and extracted data, including adverse events. Results were expressed as relative risks (RR) with 95% confidence intervals (CI).


RESULTS
Ten efficacy trials of SPf66 involving 9698 participants were included. Results with SPf66 in reducing new episodes of P. falciparum malaria were heterogeneous: it was not effective in four African trials (RR 0.98, 95% CI 0.90 to 1.07; 2371 participants) or in one Asian trial (RR 1.06, 95% CI 0.90 to 1.25; 1221 participants). In four trials in South America the number of first attacks with P. falciparum was reduced by 28% (RR 0.72, 95% CI 0.63 to 0.82; 3807 participants). It did not reduce episodes of P. vivax malaria or admission to hospital with severe malaria. Trials have not indicated any serious adverse events with SPf66 vaccine.


CONCLUSIONS
There is no evidence for protection by SPf66 vaccines against P. falciparum in Africa. There is a modest reduction in attacks of P. falciparum malaria following vaccination with SPf66 in South America. There is no justification for further trials of SPf66 in its current formulation. Further research with SPf66 vaccines in South America or with new formulations of SPf66 may be justified.
Graves
P
P
Centers for Diseases Control and Prevention, Division of Parasitic Diseases, Mailstop F42, Building 102, Room 2113, 4770 Burford Highway NE, Atlanta, GA 30306, USA. pgraves@cdc.gov
Gelband
H
H
D006801:Humans; D008288:Malaria / Q000517:prevention & control*; D017780:Malaria Vaccines / Q000276:immunology / Q000627:therapeutic use*; D015800:Protozoan Proteins / Q000276:immunology / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D011994:Recombinant Proteins / Q000276:immunology / Q000627:therapeutic use*; D014614:Vaccines, Synthetic / Q000276:immunology / Q000627:therapeutic use
D017780:Malaria Vaccines; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C066269:SPf66 protein, Plasmodium; D014614:Vaccines, Synthetic