[1] Pertussis caused by B. parapertussis manifests with similar symptoms to B. pertussis-derived disease, but in general tends to be less severe.

This antigen protects B. parapertussis against antibodies specific to B. pertussis, so the bacteria are free to colonize the host's lungs without being subject to attack by previous antibodies.

The first infects humans and is responsible for a minority of cases of the disease pertussis (also known as whooping cough).

[4] The second, ovine, lineage causes chronic nonprogressive pneumonia in sheep.

[6] This disease can be symptomatic or asymptomatic and may predispose hosts to secondary infection.