Page 57 of articles about swine-diseases

Resolving the basis of viral and host variation will require identification and characterization of key B- and T-cell epitopes conserved among diverse PRRSV, and of the molecular and structural details of key effector antibodies, T-cell antigen receptors, and MHC molecules that mediate broad, cross-protective immunity.

Although a commensal, M. hyorhinis may cause serious systemic disease through mechanisms that are not fully understood.