By: Austin Weynand, MHS (MS3)
Dr. Bente knows ticks. Notorious for transmitting a menagerie of human and animal illnesses, the tick is better known in America for its association with Lyme and rickettsial diseases but feared in other countries for a number of lethal viruses. At the
Galveston National Laboratory, Dr. Bente runs the world’s first BSL-4 laboratory dedicated to the scrutiny of pathogenic tick-host transmission. In focus today are his efforts against Crimean-Congo hemorrhagic fever virus (CCHFV), the most prevalent
tick-borne hemorrhagic virus in the world.1
Crimean-Congo Hemorrhagic Fever (CCHF) has traditionally been combated through case management; the gamut of treatment runs from supportive care to antiviral medications, such as ribavirin. Vaccination, however, remains a strategy of interest to the keen
arbovirologist. Domestic animals, namely cattle, serve as reservoir to CCHFV, which is then vectored to humans via the bite of hard ticks of the Hyelomma genus.2 The virus enjoys a complex life cycle between ticks and its animal hosts, often going
undetected by humans until facing an outbreak and posing a persistent threat of spillover. Thus, one promising approach to protecting human lives is to immunize cattle, as vaccines for animals tend to be cheap, effective, and easier to get off the
ground. The case is helped by the fact that efforts to develop human vaccines against CCHF have been largely unsuccessful.
Of note, there is another animal vaccine undergoing development in tandem with the one studied by Dr. Bente. That candidate concerns itself with CCHFV entry into host cells, honing in on a glycoprotein called GP38.3 Conversely, Bente’s vaccine targets
the tick itself (“anti-tick, not anti-pathogen”, he clarifies). His mark is subolesin, a protein vital to the tick’s digestion of blood; this antigen has proved susceptible to attack by vaccine-mediated antibodies from the animal
being fed upon.4 Ingeniously, Bente’s lab uses an attenuated rabies virus as vaccine backbone to present the subloesin antigen, boosting cattle immune response against either protein. Dr. Bente’s team will soon be inoculating cows under
laboratory conditions and quantifying conferred immunogenicity. Success will build credibility towards animal immunization as a reliable One Health approach to protecting humans against CCHF.
Dr. Bente and I talked a lot about vaccine development. There are complex obstacles to obtaining the right funding, resources, and political will, and I asked how they differ between humans and non-humans. "For one, it’s easier to get a veterinary
license than a human license for vaccines," Bente explains. Moreover, the cost for animal vaccines is much lower. "A rabies vaccine [series] for a scientist could cost hundreds of dollars, but a rabies vaccine for livestock may cost pennies." Not
in its favor, however, is the less appealing market and return on investment of animal vaccines, a source of investor hesitation. But Dr. Bente, an epidemiologist with his own investment in One Health, sees opportunity for global disease prevention.
The funding and resources are there; translation to the real world would be next.
- Crimean-Congo haemorrhagic fever. (n.d.). Retrieved November 11, 2023, from https://www.who.int/news-room/fact-sheets/detail/crimean-congo-haemorrhagic-fever
- Transmission | Crimean-Congo Hemorrhagic Fever (CCHF) | CDC. (2019, February 27). https://www.cdc.gov/vhf/crimean-congo/transmission/index.html
- Scher, G., Bente, D. A., Mears, M. C., Cajimat, M. N. B., & Schnell, M. J. (2023). GP38 as a vaccine target for Crimean-Congo hemorrhagic fever virus. Npj Vaccines, 8(1), Article 1. https://doi.org/10.1038/s41541-023-00663-5
- Sorvillo, T. E., Rodriguez, S. E., Hudson, P., Carey, M., Rodriguez, L. L., Spiropoulou, C. F., Bird, B. H., Spengler, J. R., & Bente, D. A. (2020). Towards a Sustainable One Health Approach to Crimean–Congo Hemorrhagic Fever Prevention:
Focus Areas and Gaps in Knowledge. Tropical Medicine and Infectious Disease, 5(3).
https://doi.org/10.3390/tropicalmed5030113