Scientists say that two new vaccine therapies have finally produced protective immune responses against prions in mice, and that such therapies could be further developed to work in humans or livestock.

The vaccines rely on training the immune system to make defensive antibody molecules. Howard Federoff at the University of Rochester Medical Center in New York, US, and colleagues engineered a harmless virus to carry genetic code for antibodies that bind to prion proteins.

Researchers injected the modified virus into the brains of mice and waited for four weeks – giving cells inside the rodents’ brains time to produce antibodies from the introduced code. These experimental mice, and their control counterparts, then received injections of infectious mouse prion proteins into their bellies.

Toxic clumps

The prions travelled to the animals’ brains where they caused other proteins to misfold and form deadly, toxic clumps in the nervous system. As expected, the control mice died from these toxic effects within about 200 days.

Source: newscientist.com