The present invention relates, in general, to granulocytic ehrlichia (GE) proteins. In particular, the present invention relates to nucleic acid molecules coding for GE S2, S7, S22, S23, C6.1, C6.2, S11, E8, E46#1, and E46#2 proteins; purified GE S2, S7, S22, S23, C6.1, C6.2, S11, E8, E46#1, and E46#2 proteins and polypeptides; recombinant nucleic acid molecules; cells containing the recombinant nucleic acid molecules; antibodies having binding affinity specifically to GE S2, S7, S22, S23, C6.1, C6.2, S11, E8, E46#1, and E46#2 proteins and polypeptides; hybridomas containing the antibodies; nucleic acid probes for the detection of nucleic acids encoding GE S2, S7, S22, S23, C6.1, C6.2, S11, E8, E46#1, and E46#2 proteins; a method of detecting nucleic acids encoding GE S2, S7, S22, S23, C6.1, C6.2, S11, E8, E46#1, and E46#2 proteins or polypeptides in a sample; kits containing nucleic acid probes or antibodies; bioassays using the nucleic acid sequence, protein or antibodies of this invention to diagnose, assess, or prognose a mammal afflicted with ehrlichiosis; therapeutic uses, specifically vaccines comprising S2, S7, S22, S23, C6.1, C6.2, S11, E8, E46#1, and E46#2 proteins or polypeptides or nucleic acids; and methods of preventing or inhibiting ehrlichiosis in an animal.