Malaria is a parasitic disease spread by mosquitoes. It affects millions of people worldwide and causes significant illness and mortality. Uncomplicated malaria presents with symptoms such as fever, headache, muscle pain, and vomiting, and children commonly present with rapid breathing, cough, and convulsions. Severe malaria causes unconsciousness and death. Vaccines are widely considered a necessary component for the complete success of malaria control. The parasite moves through several life-cycle stages in the human body, during which its molecular makeup changes, at least partially. Vaccines specific for each stage (ie targeting different antigens) are under development. This review looked at vaccinations targeted at the asexual (blood) phase of the parasite's life, when the parasites are in red blood cells. One vaccine for this phase, MSP/RESA (also known as Combination B), has been tested in field trials in Papua New Guinea. It reduced the density of parasites in the blood, but it did not prevent malaria attacks. Blood-stage vaccines are being actively pursued in further research.
Graves, P.M.; Gelband, H. Vaccines for preventing malaria (blood-stage). Cochrane Database of Systematic Reviews (2006) (Issue 4) Art. No.: CD006199. [DOI: 10.1002/14651858.CD006199]