Researcher's nanoparticle key to new malaria vaccine

A self-assembling nanoparticle designed by a UConn professor is the key component of a potent new malaria vaccine that is showing promise in early tests.

For years, scientists trying to develop a malaria vaccine have been stymied by the malaria parasite's ability to transform itself and "hide" in the liver and red blood cells of an infected person to avoid detection by the immune system.

But a novel protein nanoparticle developed by Peter Burkhard, a professor in the Department of Molecular & Cell Biology, in collaboration with David Lanar, an infectious disease specialist with the Walter Reed Army Institute of Research, has shown to be effective at getting the immune system to attack the most lethal species of malaria parasite, Plasmodium falciparum, after it enters the body and before it has a chance to hide and aggressively spread.

The key to the vaccine's success lies in the nanoparticle's perfect icosahedral symmetry (think of the pattern on a soccer ball) and ability to carry on its surface up to 60 copies of the parasite's protein. The proteins are arranged in a dense, carefully constructed cluster that the immune system perceives as a threat, prompting it to release large amounts of antibodies that can attack and kill the parasite.

In tests with mice, the vaccine was 90-100 percent effective in eradicating the Plasmodium falciparum parasite and maintaining long-term immunity over 15 months. That success rate is considerably higher than the reported success rate for RTS,S, the world's most advanced malaria vaccine candidate currently undergoing phase 3 clinical trials, which is the last stage of testing before licensing.