Summary

Rhodococcus equi is an intracellular pathogen that causes severe and fatal respiratory disease in foals known as rattles. In this project, the capacity of a prototype vaccine for R. equi to stimulate immune responses in foals will be determined. Studies have shown that cellular and antibody immune responses are important in preventing the severe pneumonic infections associated with R. equi. Prior to COVID-19 adenoviruses were successfully used as vaccine vectors to target intracellular pathogens such as Mycobacterium tuberculosis, a pathogen closely related to R. equi. To prevent the development of rattles, strong cellular immune responses are required to identify and destroy R. equi infected cells before the disease develops. Importantly, adenoviral vectors are known to elicit strong cellular immune responses in young mammals, making them ideally suited for preventing rattles in foals. We have developed a prototype vaccine using a modified human adenovirus that expresses the immunogenic R. equi protein VapA. Our vaccine does not produce infectious viruses and therefore poses no risk to humans working with immunised horses. Testing of the prototype vaccine in a mouse challenge model demonstrated

Program

Thoroughbred Horses

Research Organisation

The University of Queensland