Human vaccination against Q fever

Q fever is a zoonotic disease (i.e. a disease that can be transmitted from animals to humans) caused by the Coxiella burnetii bacterium (C. burnetii).
For humans infected by C. burnetii, more than 60 percent of the cases are asymptomatic. A distinction is made, in the case of those that do fall ill, between acute Q fever, most commonly manifested as flu-like symptoms, sometimes accompanied by pneumonia and hepatitis, and the far less common chronic Q fever, which predominantly manifests itself as endocarditis (inflammation of the tissue lining the inner layer of the heart chambers and the heart valves). Generally speaking, acute Q fever is a self-limiting disease, but research shows that forty percent of patients still experience health problems and/or impairments a year after first contracting the disease. Chronic Q fever occurs more frequently in individuals with underlying conditions, such as (hidden) heart valve defects.