First effective blood-state malaria vaccine identified

Scientists at the University of Maryland School of Medicine have identified the first effective blood-stage malaria vaccine and found that it produced a high level of strain-specific protection in a Phase II trial.  
The researchers, in collaboration with the University of Bumako in Mali and other partners, found that participants in the experimental blood-stage vaccine trial were well protected against parasites with a similar genetic make-up to the malaria strain used in the vaccine.
"This trial is the first good news that we have had in a long while for blood-stage vaccines," Christopher Plowe, a professor of medicine, epidemiology and public health and microbiology and immunology and the senior author of the study, said. "The fact that we saw this partial protection against malaria has reinvigorated the entire field. This gives us hope that we could create an effective blood-stage vaccine by using a precise combination of just the right strains to protect against most types of malaria."
A successful blood-stage malaria vaccine could be similar to the polio vaccine, which was created by choosing three specific strains of polio to create broad immunity to the disease, Plowe said.
The vaccine, called FMP2.1/AS02A, is based on a single strain of the Plasmodium falciparum malaria parasite, which is the most common and deadliest form of the parasite found in Africa. The vaccine consists of a malaria protein combined with an adjuvant.

The study involved 400 Malian children and found that 64 percent of the children infected with a parasite similar to the protein in the vaccine, AMA1, were protected against malaria. The vaccine was 17 percent protective against all strains of malaria.
By targeting the blood stage of the parasite, it can be prevented from multiplying inside red blood cells. The most advanced malaria vaccine, RTS,S/AS01, attacks an earlier stage of the parasite and has an only about 50 percent protective efficacy.

"Our malaria group is world-leading, with state-of-the-art clinical facilities and cutting edge basic science laboratories in Baltimore and throughout the world, including in malaria-ravaged areas of the globe," E. Albert Reece, the vice president for medical affairs for the University of Maryland, said. "I have confidence that we are making significant strides toward a solution for this deadly illness that devastates much of the world."