Fresh hope of abolishing ‘eye-bleeding’ Ebola which kills up to 90% of victims, as pill shows ‘100% protection’
SCIENTISTS have found a pill that offers ‘100 per cent protection’ against Ebola – sparking hopes of eradicating the deadly eye-bleeding disease.
Ebola is a rare but severe illness that can kill up to 90 per cent of its victims.
First identified in 1979, outbreaks of the disease have been reported with increasing frequency since 1994.
The most recent Ebola outbreak has been declared in Uganda.
The disease previously resulted in 2,299 deaths when it tore through Uganda and the Democratic Republic of Congo (DRC) between 2018 and 2020.
Meanwhile, the 2013–2016 West African Ebola epidemic infected 28,600 people and caused 11,325 deaths.
Scientists have raced to create vaccines and treatments that mimic natural antibodies – called monoclonal antibodies (mAb) – to eradicate the deadly disease since its discovery.
A vaccine was only widely approved in 2019, and while two mAb-based treatments have shown success in human clinical trials, they need need to be at cold temperatures so they remain effective.
This is costly and can make the treatments difficult to administer in the world’s poorest regions.
Researchers from The University of Texas Medical Branch at Galveston said: “There from the here remains a need for Ebola virus disease countermeasures that can be more rapidly and widely deployed in resource-limited regions.”
Treatments given orally in pill form would be much easier to dish out during outbreaks, they noted.
Thomas Geisbert, a virologist who lead the new study published in Science Advances, told AFP: “We’re really trying to come up with something that was more practical, easier to use, that could be used to help prevent, control, and contain outbreaks.”
For their study, researchers tested the antiviral Obeldesivir, a “polymerase inhibitor” that blocks an enzyme responsible for the virus replicating.
The drug was previously found to be able to combat several RNA viruses – including the filovirus family to which Ebola belongs – when given 24 hours after exposure.
The research was carried out on macaques – a type of monkey – and research infected the primates with Ebola through their muscles.
This causes the disease to strike much faster and makes it harder to track the drug’s effect.
This time round, the team infected rhesus and cynomolgus macaques with a high dose of the Makona variant of the Ebola virus through their noses and mouths.
A day after exposure, ten monkeys then received an Obeldesivir pill daily for ten days, while three control monkeys received no treatment at all and died.
Obeldesivir protected 80 percent of the cynomolgus macaques and 100 percent of the rhesus macaques, which are biologically closer to humans.
The disease onset was slower, so researchers were able to explore how the drug worked in real time.
Symptoms of Ebola
Ebola first manifests as a high fever, intense muscle and joint pain, headaches and a sore throat.
Initial symptoms are often followed by:
- Vomiting and diarrhoea
- Rashes on the skin
- Kidney and liver failure
- Internal and external bleeding.
After recovering from Ebola, some people may have symptoms for two years or longer.
These symptoms can include:
- Feeling tired
- Headache
- Muscle and joint pain
- Eye pain and vision problems
- Weight gain
- Belly pain and loss of appetite
- Hair loss and skin problems
- Trouble sleeping
- Memory loss
- Hearing loss
- Depression and anxiety
People can get infected with Ebola by touching:
- Infected animals when preparing, cooking or eating them
- Body fluids of an infected person such as saliva, urine, faeces or semen
- Things that have the body fluids of an infected person like clothes or sheets.
Ebola enters the body through cuts in the skin or when touching one’s eyes, nose or mouth.
Source: WHO
The drug not only cleared the virus from the treated monkeys’ blood but also triggered an immune response, helping them develop antibodies while avoiding organ damage from the immune reaction.
Though the number of monkeys the Obeldesivir pill was tested on was relatively small, Dr Geisbert told AFP the results were significant because the macaques were exposed to an extraordinarily high dose of the virus — roughly 30,000 times the lethal dose for humans.
He said one of the most exciting aspects of Obeldesivir is its “broad-spectrum” protection, compared to the approved antibody treatments that only work against the Zaire species of Ebola – there are four species of Ebola.
“That’s a huge advantage,” Dr Geisbert said.
Researchers said their results indicate that Obeldesivir could be given to people after being exposed to Ebola.
“These findings suggest that Obeldesivir treatment affords the opportunity for the development of adaptive immunity while mitigating excessive inflammation, potentially preventing fatal outcomes,” they wrote.
But they said the drug needs to be tested further.
“Results from these preclinical studies support further advancing Obeldesivir as a post exposure prophylaxis for filovirus infections.
“Future testing of Obeldesivir treatment in nonhuman primates beyond the early filovirus post exposure prophylaxis should focus on evaluating the dose, the duration of treatment and delaying treatment until the onset of detectable clinical signs of illness.
“The benefits of oral interventions promote the rapid and wide deployment as post exposure prophylaxis particularly in a resource limited outbreak setting.”
Pharmaceutical maker Gilead is currently studying Obeldesivir in Phase 2 clinical trials for Marburg virus, a close relative of Ebola.