In a world-first, Griffith University researchers have developed a new vaccine in pre-clinical studies to treat human babesiosis, a tick-transmitted disease closely related to malaria.
Lead researcher Professor Michael Good AO, said the research team including PhD candidate Hanan Al-Nazal and researcher Dr Danielle Stanisic, developed a whole parasite Babesia vaccine that acts as a universal vaccine, inducing immunity against different human Babesia species.
“Babesiosis affects the red blood cells similar to malaria in humans and animals and presents as a flu-like illness and anaemia. People most at risk of severe disease are the elderly, the immunosuppressed and those without spleens. It also affects those who need blood transfusions,’’ Professor Good said.
“In pre-clinical studies we have shown this vaccine can kill the parasite and induce a protective immune response. The immune response is tied to two crucial aspects of the immune system – T Cells and macrophages (which clear bacteria and other germs).”
The vaccine is delivered using a liposomal platform (where the killed parasite is contained in a lipid vesicle). The advantage of liposomes is that they can be freeze-dried so they are suitable for transporting into the field.
Dr Stanisic said as far as they were aware, this was the first time a whole parasite vaccine for babesia had been developed.
“The idea behind a whole parasite vaccine is that there are thousands of proteins in the vaccine, some of which are going to the be the same between different parasite strains. These invariant proteins would be the target of broadly protective immune responses and the vaccine is thus expected to provide widespread coverage and protection when tested in the field.
“The liposomal platform used in this study also has application for veterinary vaccines targeting the Babesia parasites that infect animals including cattle and companion animals such as dogs. For example, babesiosis affects cattle in northern Australia and other countries so an effective vaccine that is able to be freeze-dried would be a significant advantage for farmers.”
“The outcomes of this study sets the scene for the further progression of this universal vaccine candidate and potentially the discovery of other whole parasite vaccines.”
The researchers hope to progress to human clinical trials next year.
The study was a collaboration with scientists from the University of Queensland and the US Food and Drug Administration. It is published in Cell Host and Microbe.