Marburg virus, shown here, isn't as well known as Ebola, but can also cause severe illness and death. (Credit: Dr. Tom Geisbert/University of Texas Medical Branch)

Researchers investigating monoclonal antibodies have cured animals, including guinea pigs and rhesus monkeys, of Marburg and Ravn viruses.

While not as well-known as the deadly Ebola virus that ravaged West Africa in an outbreak beginning in 2014, Marburg and Ravn are both also in the Filoviridae family of viruses and produce similar symptoms.

Infections can spread through person-to-person contact and often cause bleeding, leading to severe illness and death.

A team led by Dr. Thomas W. Geisbert at the University of Texas Medical Branch and Dr. Larry Zeitlin of Mapp Biopharmaceutical Inc., selected three monoclonal antibodies for further investigation, from a set created from a person who had survived Marburg disease.

The antibodies bind to a specific part of the invading virus.  One of the antibodies, MR191-N, was first tested in guinea pigs.  After administering the antibody up to four days after infection, the scientists found that the animals were completely protected from either the Marburg or Ravn viruses.

Next the scientists tested the antibody in rhesus monkeys.  The monkeys received two doses of MR191-N, the first given four days after infection and the second after seven days.  The antibody protected all of the monkeys involved in the study from the Marburg virus.  All five monkeys that were infected with Ravn virus and given MR191-N five days later, also survived, while four out of five infected with Marburg were protected.

The new antibody required less dosing than other experimental Marburg treatments which required daily doses for seven to 14 days, and the treatment could be first administered longer after infection.

“These findings extend the growing body of evidence that monoclonal antibodies van provide protection during advanced stages of disease with highly dangerous viruses and could useful during an epidemic,” Geisbert said in a prepared statement.

The team is continuing their work to test safety of the treatment and hope to move into early human trials.

The research was funded by the National Institutes of Health’s National Institute of Allergy and Infectious Disease and National Center for Advancing Translational Sciences. 

The findings were published in Science Translational Medicine.

Contributing Editor/Science Writer