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.

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 invention relates to novel hybrid peptides developed from the combination of membrane surface protein peptide fragments present in anaplasmosis microorganisms, and in particular, bacteria of the species Anaplasma marginale. The present invention further relates to hybrid peptide sets, compositions and kits comprising such novel hybrid peptides, their uses and methods of inducing immune response. Each hybrid peptide, according to the present invention, comprises two or more peptide fragments of amino acid sequences as defined in the present invention linked together by means of a spacer element. The combined peptide fragments are protein peptide fragments of MSP1, MSP1a, MSP1b, MSP2, MSP2-HRV, MSP3, OMP7, OMP8, VirB9 and VirB10.

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

Attenuated vaccines to protect vertebrate animals and people against tick-born rickettsial, Ehrlichia and Anaplasma species infections is disclosed. Also disclosed are methods to modify the organism to achieve the desired immunity through the modification of a novel genetic region involved in pathogenesis. These compounds represent a needed vaccine against an organism causing life-threatening febrile illness in humans and animals, and also represent the potential to develop new classes of drugs targeting the gene products of genes Ech_0379 and Ech_0230, and their homologs of other related rickettsial pathogens.

The present invention encompasses a vaccine composition and method of use for treating heartworm infestation in mammals. The vaccine composition includes chimeric antigens engineered and manufactured using the genetic code (i.e., the amino acid or protein sequence) of the target sequence. After introduction of the vaccine composition containing the target antigen into the host (e.g., a canine), the host will generate antibodies as part of its robust immune response to the antigen. As the antibodies circulate through the host's plasma, heartworm larvae will consume the antibodies as they feed on the plasma. The antibodies will then act on internal targets of the worm recognized as antigens.

Anaplasma phagocytophilum surface proteins Asp14 and OmpA and homologous genes from Anaplasmatacaea family members are used in compositions suitable for vaccines to treat or prevent infections caused by tick-born bacteria of the Anaplasmatacaea family. Asp14 and/or OmpA proteins or peptide fragments may be used in combination with other Anaplasmatacaea surface proteins to elicit an immune response. Furthermore, antibodies to Asp14 and/or OmpA proteins can be used in diagnostic methods to determine whether an individual has contracted an Anaplasmatacaea infection. Because of the conserved invasin domains in the surface proteins, a wide range of Anaplasmatacaea infections may be diagnosed, treated or prevented using compositions of the invention.

The present invention discloses a novel recombinant protein antigen and a vaccine composition using the same, in which the novel recombinant protein antigen is derived from the conserved sequence of a TSA56 antigen and can be useful in the diagnosis of infection with tsutsugamushi and as a vaccine for tsutsugamushi.

Nucleic acids include sequences encoding Ehrlichia ruminantium epitopes which induce a CD4 immune response, and sequences encoding Ehrlichia ruminantium epitopes which induce a CD8 immune response. Multi-epitope DNA vaccines include the nucleic acids and polypeptides are encoded by the nucleic acids. Methods of eliciting an immune response against heartwater disease in a subject make use of the nucleic acids, multi-epitope DNA vaccines and polypeptides.