Problem

Tick-borne ehrlichiosis cases continue to rise globally, yet no licensed human vaccine exists and current diagnostic tools remain limited. Existing approaches struggle due to the pathogen’s antigenic variability, intracellular lifecycle, and lack of classical surface PAMPs, hindering effective immune targeting and rapid clinical detection. There is an urgent need for a broad-spectrum strategy that overcomes these limitations and addresses rising incidence and under-diagnosis of severe disease. The newly identified Ehrlichia virulence factor RipE—conserved across multiple Ehrlichia species and critical for extracellular survival—provides a breakthrough opportunity to develop a pan-Ehrlichia vaccine and complementary diagnostic assays capable of improving prevention, early detection, and clinical management in both human and veterinary health settings.

Solution

Researchers at The Ohio State University have discovered and validated RipE, a previously uncharacterized Ehrlichia virulence factor essential for bacterial survival during the extracellular stage of infection. RipE is surface-expressed on the infectious dense-core form of Ehrlichia and is highly conserved across pathogenic species including E. chaffeensis, E. canis, E. muris, and E. ruminantium.

Current vaccine efforts are hindered by antigenic diversity and poor induction of cross-protective immunity. This technology addresses these gaps by targeting RipE, which drives ATP maintenance and extracellular viability—functions not shared by other surface antigens. The platform includes:

1. A subunit vaccine composed of recombinant RipE or antigenic fragments.
2. A live-attenuated vaccine based on genetically modified E. japonica lacking RipE expression, demonstrating reduced virulence and strong immunogenicity.
3. A diagnostic assay that detects RipE-specific antibodies for rapid and early identification of infection

The technology’s broad species coverage, unique mechanism of action, and compatibility with multiple vaccine formats make it highly adaptable for human health, veterinary markets, biodefense preparedness, and wildlife disease management. Companies benefit from a first-in-class, cross-protective solution with strong translational potential across multiple commercial verticals.

Benefits

• First pan-Ehrlichia protection strategy, targeting a conserved, essential virulence factor.
• Demonstrated cross-species protection, including protection against E. chaffeensis, the agent of human monocytic ehrlichiosis.
• Multiple vaccine formats (subunit, live-attenuated) support broad commercialization pathways.
• Diagnostic utility via RipE-specific IgG detection enables early, accurate infection confirmation.
• Improved safety and efficacy through targeted attenuation and robust neutralizing antibody induction.

Applications

• Human vaccines for prevention of monocytic ehrlichiosis.
• Veterinary vaccines for dogs, livestock, and wildlife reservoirs.
• Companion diagnostic assays (blood or tissue-based) for rapid, point-of-care detection.
• Biodefense and public health surveillance for emerging tick-borne pathogens.