The present disclosure provides compositions and methods for reducing the incidence of and/or severity of diseases associated with tick-borne pathogens. In preferred forms, the compositions comprise a recombinant antigenic protein subunit that has been glycosylated. Some preferred subunits include the MAP1 protein of Ehrlichia ruminantium, the p30-1 sequence from Ehrlichia canis, the p28-Omp19 protein from Ehrlichia chaffeensis, and the MSP4 protein from Anaplasma marginale. Administration of such compositions to an animal in need thereof provides protection against clinical signs of infection in susceptible animals.

The present disclosure provides immunogenic compositions and vaccines effective for reducing the incidence of or severity of clinical signs or symptoms of infection by a tick-borne pathogen selected from the group consisting of Rickettsia rickettsii, Ehrlichia chaffeensis, Ehrlichia canis, Ehrlichia ruminantium, Anaplasma marginale, and Anaplasma phagocytophilum. In preferred forms, the immunogenic composition comprises an inactivated whole cell bacteria selected from the group consisting of Rickettsia rickettsii, Ehrlichia chaffeensis, Ehrlichia canis, Ehrlichia ruminantium, Anaplasma marginale, Anaplasma phagocytophilum, and any combination thereof, together with an adjuvant.

Provided herein are chimeric polypeptides that may be used, e.g., for the diagnosis of or vaccination against Ehrlichia chaffeensis and/or Ehrlichia canis.

A vaccine composition comprising a virus antigen wherein the composition comprises less than 5% serum, wherein the virus antigen is a whole virus or derived from a whole virus, the vaccine composition reduces, prevents or avoids cross-stitch spinal deformity in the treated animal. Said vaccine composition for use in a method of treating a disease caused by the intracellular pathogen in an animal and reducing, preventing or avoiding cross-stitch spinal deformity in the treated animal. In cross-stitch vertebra the intervertebral space is completely collapsed. A vaccine composition for use as defined above wherein the animal is a fish. In an embodiment the pathogen is salmon alpha virus (SAV).

Provided herein are immunogenic compositions that may be used, in some aspects, to induce an immune response against an Ehrlichia such as Ehrlichia canis. In some embodiments, the immunogenic composition comprises an E. canis bacterin and/or adjuvant, such as for example an emulsion or liposomal adjuvant. Related methods such as for diagnosis of or vaccination against ehrlichiosis are also provided.