Why is a vaccine against malaria seen as the main hope for the future?
This answer is courtesy of a medical doctor assisting us with answering your questions.
A vaccine is seen as the great hope for the future because the malaria parasite has an extraordinary talent for developing resistance very rapidly against each class of drug that is introduced into the arsenal against it. This is accomplished by various mechanisms, such as concentrating and pumping the drug back outside its outer membrane, mutation of drug binding sites rendering the drug molecules incapable of attaching to or entering the cell in order to do its work and alteration of other enzymes within the cell to change the pH (acidity), again rendering certain drugs ineffective, even if they do get in (among other mechanisms!). That said, the development of an effective vaccine has been difficult due to changing surface proteins against which these vaccines are being developed. In order to work, the vaccine has to be developed targeting highly “conserved” outer proteins which do not undergo genetic mutation frequently…ie, not so much of a moving target.