Researchers at The University of Texas Medical Branch (UTMB) have identified a unique ebolavirus strain that could change how scientists study and treat deadly hemorrhagic fevers.

The research, published in Nature Communications, reveals that the recently discovered Bombali ebolavirus, which was originally detected in wild bats across Africa, causes the same severe symptoms as Ebola virus disease but carries a 100% survival rate in advanced laboratory models.

The discovery gives researchers a nonlethal roadmap to study how a biological system successfully defeats the virus.

Studying ebolaviruses has been challenging because the most pathogenic strains — such as Ebola, Sudan, and Bundibugyo — damage organs and shut down systems so rapidly that researchers have only a narrow window to analyze effective immune responses.

By testing a lab-rebuilt version of the Bombali virus in monkeys that mimic human responses to Ebola, professor Thomas Geisbert, PhD, and associate professor Robert Cross, PhD, and their team in the Department of Microbiology and Immunology at UTMB observed how the virus interacted with a complex living system. The virus behaved like textbook Ebola, moving directly into critical target tissues such as the liver, lymph nodes, and adrenal glands while triggering severe inflammation and vascular leakage.

“Despite showing these classic, high-consequence clinical signs, every subject survived the infection,” Geisbert said. “The subjects’ bodies successfully mounted a massive defense, developing virus-neutralizing antibodies and strong immune memory. This suggests that the Bombali virus possesses a significantly milder disease profile compared to its lethal counterparts, providing a live, working blueprint of what a successful cure looks like from the inside out.”

By analyzing how the body controls and clears the Bombali strain without suffering fatal organ failure, scientists can isolate the biological tipping points required to design next-generation therapeutics, antivirals, and vaccines for the deadlier strains that threaten global health.

“This study underscores the continued leadership of UTMB on the front lines of global biosecurity and infectious disease research,” Cross said. “By translating complex, field-level ecological discoveries into actionable, translation-focused laboratory breakthroughs, we continue to refine our understanding of the world's most dangerous pathogens.”

Additional researchers involved in this study:

• Galveston National Laboratory and Department of Microbiology and Immunology at UTMB: Jacquelyn Turcinovic, Karla A. Fenton, Krystle N. Agans, Viktoriya Borisevich, Daniel J. Deer, Joan B. Geisbert, Rachel O’Toole, Natalie S. Dobias, Abhishek N. Prasad, Courtney Woolsey
• MAPP Bio, San Diego: Dafna Abelson
• Department of Virology, Immunology, and Microbiology, Boston University Chobanian and Avedisian School of Medicine, Boston and National Emerging Infectious Diseases Laboratories, Boston University: John H. Connor
• Viral Special Pathogens Branch, Division of High-Consequence Pathogens and Pathology, U.S. Centers for Disease Control and Prevention, Atlanta: César G. Albariño