[Antimalarial vaccination].

Abstract

The vaccination against malaria is very difficult due to the complexity and variability of the malaria antigens and the imperfection of the available experimental models. During the last 20 years, especially since the first in vitro cultures of Plasmodium falciparum, several types of vaccines have been tried. These vaccines are directed against the sporozoites, against the merozoites or against the gametocytes. Each of the vaccines corresponds to a vaccine conception and to some well-defined goals. Despite the large number of studies, sometimes with considerable means, all of the trials have failed. In contrast, the recent work of Patarroyo, and some diverse collaborating teams, have at least partially succeeded. Vaccine trials in several countries of South America and East Africa, using the synthetic antigen SPf 66, provided protection of 30 to 50%. These results are still modest but its to their credit to be the first successful antimalaria vaccine in humans. Also, these results were evaluated by their effects on morbidity and not only on parasitaemia. Some important progress remains to be accomplished, but a decisive step has been surmounted. Also, other types of vaccines will be tried soon. They differ by their target or by their conception, notably for the anti-DNA vaccines. One or several efficient vaccines should be available within the next few years. However, no one can determine the length of the waiting period. It is unrealistic to give this vaccine all of the hopes of eradication or even control of malaria in the endemic zones. A disease epidemiologically so complex as malaria cannot be eliminated by one procedure. The success will be obtained with the judicious use of the sum of the currently available means, including antivectorial fight and protection, drug prophylaxis and drug therapy, in addition to the vaccine when it is available.