Malaria vaccine waylays parasite in liver
By Nathan Seppa
By triggering an attack on the parasite that causes malaria as it passes through the liver, a new vaccine intercepts the single-celled organism before it can enter the bloodstream and do damage.
The vaccine imparted partial or full protection to eight of nine chimpanzees that researchers infected with Plasmodium falciparum, the protozoan that causes the most lethal form of malaria in people, researchers in France report in the November Nature Medicine.
The scientists used synthetically produced versions of a protein called liver stage antigen-3, or LSA-3. The original form is found in P. falciparum when it’s a schizont. Mosquitoes carry the protozoan in an immature stage in their saliva and inject it into people. As a schizont, P. falciparum passes through the liver in only 5 days—but still represents an ideal vaccine target, says study coauthor Pierre Druilhe, a parasitologist at the Pasteur Institute in Paris.