Every day 2,000 children die from malaria in Africa alone. The infection is transmitted from human to human by biting mosquitoes and remains one of the world's most devastating diseases. Despite many years of effort a vaccine is still not available but is urgently needed, if we are to make an impact on this enormous problem.
Continual exposure can generate protection against malaria and can be acquired through an exposure to a high number of infectious mosquito bites. Parasites that are injected by a mosquito first migrate to the liver where they mature and then are released into the blood circulation and it is only here that they cause disease and fatal complications.
A very promising method for vaccination is to sufficiently weaken parasites such that they invade liver cells but then are not able to develop any further. It is, however, required that these attenuated parasites are still able to stimulate a good immune response in the liver. This can be achieved by irradiating the parasites or by genetically inactivating individual parasite genes that are active during the parasites growth in the liver. Researchers from Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands and LUMC, Leiden, the Netherlands, have now characterized a large number of parasite proteins ('proteome') that are present only during liver stage development and therefore are potential targets for inactivation.