Hoffman's vaccine works by inserting malaria genes into the DNA of human muscle cells, causing those cells to make chemical structures normally made only by the parasite. Released into the bloodstream, those chemical structures stimulate the immune system, preparing it for combat with the parasite itself. Malaria is common throughout the tropics. It ranks with tuberculosis and AIDS as one of the biggest killers among infectious diseases. Scientists have sought a malaria vaccine since 1880, when a French doctor in Algiers first identified the malaria microbe in the blood of a soldier.
Malaria is a parasite, an animal with complex tactics for evading the human immune system.
While there are many vaccines against bacterial and viral illnesses, no one has ever made a workable vaccine against a parasite.