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_0660, Ech_0379, and Ech_0230, and their homologs of other related rickettsial pathogens.

Disclosed are vaccines containing one or more immunogenic polypeptides derived from an EtpE protein from an Ehrlichia sp. or nucleic acid encoding these polypeptides. Also disclosed is a method for vaccinating a subject against Ehrlichia sp. that involves administering to the subject a composition comprising any of the disclosed vaccines. Also disclosed is a method for diagnosing and/or monitoring the treatment of Ehrlichiosis in a subject that comprising assaying a biological sample (e.g., blood, serum, or plasma sample) from the subject for the presence of an antibody that specifically binds an EtpE polypeptide. Also disclosed are methods for delivering a therapeutic or diagnostic agent to a cell in a subject that involves conjugating the agent, or a delivery vehicle comprising the agent, to polypeptide containing the C-terminal domain of an EtpE protein.

Anaplasma Marginale surface protein 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. OmpA proteins or peptide fragments may be used in combination with other Anaplasmatacaea surface proteins to elicit an immune response. Furthermore, antibodies to OmpA proteins can be used in diagnostic methods to determine whether an individual has contracted an Anaplasmatacaea infection.

Certain embodiments are direct to a vaccine composition comprising an immunizing amount of an Ehrlichia sonicate, wherein the Ehrlichia sonicate elicits a protective physiologic response. In certain aspects the Ehrlichia is one or more of E. canis, E. chaffeensis, E. muris, E. ruminantium, E. ewingii, and E. ovis.

The invention relates to a composition and a method for manufacturing semi-dry or dry particles containing a mucoadhesive polymer and a bioactive agent such as, but not limited to, an Immunogenic Substance (e.g., a vaccine), that allows the oral or nasal administration and delivery of the bioactive agent essentially unaltered to mucosal surfaces in the animal, including an aquatic animal.

The disclosure relates to outer membrane vesicles from Francisella and Piscirickettsia, and their use in vaccine compositions. In particular, the present disclosure relates to compositions and methods useful in inducing protective immunity against francisellosis or salmon rickettsial septicaemia (SRS) in fish.

Disclosed are vaccines containing one or more immunogenic polypeptides derived from an EtpE protein from an Ehrlichia sp. or nucleic acid encoding these polypeptides. Also disclosed is a method for vaccinating a subject against Ehrlichia sp. that involves administering to the subject a composition comprising any of the disclosed vaccines. Also disclosed is a method for diagnosing and/or monitoring the treatment of Ehrlichiosis in a subject that comprising assaying a biological sample (e.g., blood, serum, or plasma sample) from the subject for the presence of an antibody that specifically binds an EtpE polypeptide. Also disclosed are methods for delivering a therapeutic or diagnostic agent to a cell in a subject that involves conjugating the agent, or a delivery vehicle comprising the agent, to polypeptide containing the C-terminal domain of an EtpE protein.

Anaplasma Marginale surface protein 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. OmpA proteins or peptide fragments may be used in combination with other Anaplasmatacaea surface proteins to elicit an immune response. Furthermore, antibodies to OmpA proteins can be used in diagnostic methods to determine whether an individual has contracted an Anaplasmatacaea infection.

Anaplasma phagocytophilum surface protein AipA and/or fragments thereof which comprise an invasin domain are used in compositions suitable to elicit an immune response to treat or prevent infections caused by tick-born bacteria of the Anaplasmatacaea family. AipA proteins and protein fragments or antibodies directed to AipA proteins and protein fragments are also used in diagnostic assays to detect exposure to and/or infection with Anaplasmatacaea. AipA and/or fragments thereof are also used for these purposes in combination with one or both of Asp14 and OmpA proteins and/or fragments thereof which comprise an invasin domain. Homologs of these proteins are also used in the compositions and assays.

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_0660, Ech_0379, and Ech_0230, and their homologs of other related rickettsial pathogens.