In a major step forward for pandemic preparedness and vaccine development, scientists at the University of Texas Medical Branch and Moderna have developed and tested a groundbreaking mRNA vaccine that provides full protection against the deadly Marburg virus and the closely related Ravn virus in a preclinical animal model.
“The fact that we achieved complete protection in all vaccinated animals is a major leap,” said Dr. Alexander Bukreyev, co-senior author of the study and professor at UTMB’s Department of Pathology and Center for Biodefense and Emerging Infectious Diseases.
“Moderna’s mRNA platform is proving to be very potent when targeting highly lethal pathogens,” said Dr. Andrea Carfi, at Moderna, who is the other co-senior author.
Two mRNA vaccines were designed to target both Marburg and Ravn viruses—two genetically distinct but equally deadly pathogens that cause severe human disease with high fatality rates. Notably, the vaccines proved effective even when animals were challenged with the heterologous virus.
The findings, recently published in Nature Communications arrive amid recent Marburg outbreaks in Tanzania, Equatorial Guinea, and Ghana, underscoring the urgent global need for a safe, effective vaccine.
This is the first published evidence showing that an mRNA vaccine can elicit protective and cross-reactive immunity against two distinct members of the Orthomarburgvirus genus—offering hope for future vaccines that can counter emerging viral threats with high fatality rates and no approved treatments.
The vaccine uses a specially modified type of mRNA, packaged in lipid nanoparticles, to stimulate the immune system. It produced strong neutralizing antibodies and activated multiple immune responses that help fight off infection. Importantly, no virus was detectable in the blood of vaccinated animals after exposure—suggesting sterilizing immunity.
“This research maps, for the first time, how antibodies generated by mRNA vaccines can target different regions of the Marburg and Ravn glycoproteins to achieve protection,” said Dr. Michelle Meyer, a research scientist at UTMB and lead author of the study. “It gives us valuable insight for developing broadly protective vaccines not just for Marburg, but other emerging filoviruses.”
The study took a deep look at how the immune system responded to each vaccine. While the vaccines for Marburg virus and Ravn virus produced different types of antibodies that recognized different parts of each virus, they also triggered antibodies that targeted the same key areas on both viruses.
The vaccine works by training the immune system to spot an important protein of the virus that is responsible for its attachment to human cells, and its structure. Regions within this viral protein, known as the receptor-binding domain and the wing domain, are very similar in both Marburg and Ravn viruses. That’s what makes it possible for one vaccine to protect against both.
“By identifying immune responses that target shared regions of the virus—like the receptor-binding and wing domains—we now have a clearer path toward vaccines that protect against entire families of viruses,” said Bukreyev. “It’s a critical step toward global vaccine strategies that are faster, broader, and more resilient against emerging threats.”