A groundbreaking discovery may have been made in the fight against one of the world’s deadliest diseases. According to recent research, a single dose of an experimental pill has shown significant promise in reducing the high fatality rate of Ebola infection, at least in nonhuman primates.

The study, led by researchers at the University of Texas Medical Branch and published in the journal Science Advances, found that the oral antiviral medication obeldesivir prevented up to 100% of deaths in monkeys given a high dose of the deadliest species of Ebola. These findings suggest that obeldesivir could become a highly effective measure against Ebola and similar infections that can rapidly lead to severe bleeding and death.

Ebola is caused by several related strains of viruses, with the most commonly seen and deadliest version being the Zaire ebolavirus, which can have a fatality rate as high as 90% if left untreated. The symptoms of Ebola initially resemble those of the flu, including fever and aches, but can quickly progress to widespread organ damage and heavy internal bleeding.

As a zoonotic disease, Ebola outbreaks typically begin when a person comes into contact with infected animals, such as African fruit bats. However, it can also spread between people through close contact with bodily fluids, including blood and semen. While the rapid progression of symptoms and high lethality of Ebola often prevent the infection from spreading widely, it has occasionally sparked large-scale outbreaks, such as the 2014-2016 outbreak in West Africa that infected almost 30,000 people and killed over 11,000.

Currently, there are effective approved vaccines and treatments for some species of Ebola, but the vaccine supply is limited, and the current antibody-based treatments have to be stored in cold conditions and taken intravenously, limiting their availability and usefulness. The UTMB researchers believe that obeldesivir, an oral version of the antiviral remdesivir, originally developed to treat COVID-19, can represent a significant step forward in Ebola treatment.

In their study, the researchers gave cynomolgus and rhesus macaques a lethal dose of a variant of Zaire ebolavirus, followed by obeldesivir a day after infection. The results were impressive, with 100% of rhesus macaques given obeldesivir surviving their infection, and 80% of cynomolgus macaques doing the same. The treatment delayed the virus’ ability to replicate and even seemed to promote the monkeys’ adaptive immune response to it.

The team’s earlier work with monkeys has also found that obeldesivir might be effective against Sudan virus, the second most commonly encountered species of Ebola. Additionally, the researchers found that obeldesivir could protect monkeys from Marburg, another deadly cousin of Ebola, which recently sparked an outbreak in Tanzania that killed at least 10 people.

While more research is needed to validate the drug’s potential against Ebola in humans, the researchers are hopeful that obeldesivir can become a broadly applied and more convenient weapon against these deadly infections. As they wrote in their paper, “For outbreak response, oral antivirals might present substantial advantages over currently approved intravenous drugs, such as easy supply, storage, distribution, and administration.”

The potential for obeldesivir to become a game-changer in the fight against Ebola is significant, and further research is eagerly anticipated to confirm its effectiveness in humans.