The malaria vaccine: seventy years of the great immune hope.

The cluster of seminal microbiological discoveries at the end of the 19th century through to the first quarter of the 20th century gave rise to the expectation that the control of malaria would be by scientific technology (as opposed to the 'brute force' of bonification/massive engeneering works) and that technology would be immunization by a malaria vaccine. Immunology's foundation was in microbiology and the two related disciplines matured concurrently. Immunization with dead or inactivated microorganisms became immunology's strongest arm, affording protection against many major diseases such as smallpox, anthrax, rabies, yellow fever and tetanus. So why not malaria? In the pre-World War II era there were no chemotherapeutic/prophylactic drugs practical for the control of malaria and a vaccine seemed the easy, rational path to that objective. From 1910 to about 1950 there were numerous attempts in humans and primate and avian models to devise a malaria vaccine. However, it soon became apparent that the malaria parasites, because of their complex, stage-specific antigenic identity as well as their relatively poor immunogenicity, would be much more difficult to use as a vaccine than the bacteria or viruses. There were some experimental successes, but none in humans.