There is no vaccine or treatment available for the Bundibugyo strain of Ebola that is spreading in the Democratic Republic of the Congo (DRC) and Uganda, but this week three vaccine developers were awarded $60m (£45m) in emergency funding as the race to halt the outbreak ramps up.
Security issues in the affected region of the DRC, where conflict has displaced tens of thousands, have made it challenging to set up trials to test drugs. Militias operate in the area and some Ebola treatment centres have been attacked.
But researchers said they were ready to begin as soon as conditions allowed.
“Every day counts in the race against this deadly disease,” said Dr Richard Hatchett, chief executive of the Coalition for Epidemic Preparedness Innovations (CEPI), which announced the funding on Monday.
The vaccines are just part of the work scientists across the globe are undertaking; treatments and preventative measures are also in development. Here are some of the contenders:
The IAVI vaccine
Considered the “most promising candidate vaccine” by the WHO, the International Aids Vaccine Initiative (IAVI) uses the same technology as an existing Ebola vaccine, Ervebo. Ervebo targets the more common Zaire strain of the virus.
The WHO expects it to take seven to nine months before doses of the rVSV Bundibugyo vaccine are ready for clinical trials. Mark Feinberg, IAVI’s president, said they were working to accelerate the timeline as much as possible.
Security issues have hampered the response to Ebola, making it hard to set up drug trials and leading to the destruction of clinics. Photograph: Michel Lunanga/Getty Images
The world should have been more prepared, Feinberg said. While there were suggestions after the 2014-16 Ebola outbreak in west Africa that vaccines should be prepared, tested and stockpiled against viruses of this kind, they did not result in comprehensive action.
“The technologies to make an efficacious Bundibugyo vaccine are available to us, but we need to do the work to demonstrate that they do work,” he said. “And we hopefully will do better in the future as a global health community.”
The Oxford vaccine
The ChAdOx1 Bundibugyo vaccine, being developed by Oxford University with the Serum Institute of India, could be available faster than IAVI’s candidate, with trials within two or three months.
WHO experts want to see more data from tests in animals to confirm its suitability.
It uses the same technology as the Oxford/AstraZeneca Covid-19 jab. Prof Teresa Lambe of the Oxford Vaccine Group and Pandemic Sciences Institute, said she hoped it would ultimately not be needed, but the team was moving quickly.
“We have started the animal studies and we are going to be progressing with partners around the world, both in the UK and the US, to get more animal studies initiated as rapidly as we can,” she told a press briefing. The Serum Institute said it could make as many doses as needed.
The Moderna vaccine
Moderna’s vaccine did not appear on the WHO’s candidate list – the company said it was still assessing its response when the WHO’s expert panel met to make recommendations.
The jab would use mRNA technology – a prominent vaccine platform during Covid – and the company hopes it could be ready for trials within months.
CEPI has committed up to $50m to support preclinical development and early clinical testing of Moderna’s vaccine.
Stéphane Bancel, chief executive of Moderna, said: “We will move with urgency and scientific rigour to support the response and help bring a potential vaccine closer to the communities that need it most.”
Three potential treatments
Three medicines already exist that scientists believe show promise as potential Bundibugyo treatments: MBP134 and Maftivimab, monoclonal antibodies that mimic the effects of the immune system, and the antiviral remdesivir.
The antiviral drug remdesivir is being looked at as a potential treatment for Ebola. Photograph: Ulrich Perrey/AFP/Getty Images
Amanda Rojek, associate professor of health emergencies at the UK’s Pandemic Sciences Institute will be working on the Partners trial, designed to find the most effective treatment.
“We’re effectively close to ready to go,” Rojek said. The drugs exist, and investigators are seeking regulatory approval from authorities in the DRC and Uganda.
A key hurdle is “making sure that we can operationalise safely”, she said. “We will implement the trial at a point at which patients are receiving optimised supportive care and we can manage the safety of our teams in a challenging environment.”
Properly assessing that drugs are safe and effective is vital, she stressed. “It is important in any patients that we manage in our clinical practice all around the world that we have an evidence basis for the care.”
The prevention drug
For the first time in an Ebola outbreak, doctors will test a prevention drug – giving it to contacts of cases to see if it stops them developing the disease.
A pill of the antiviral drug obdeldesivir provided up to 100% protection in monkeys against two other strains of Ebola when given daily for 10 days, within 24 hours.
Prof Christophe Fraser of the UK’s Oxford University will be working on the trial. He said results will depend not only on the drugs’ effectiveness, but also on teams on the ground being able to identify the right people to take part.
“A trial goes quicker if the intervention is very effective. If it is less effective, then it takes longer,” he said. It also depends on the size of the outbreak and “the ability to follow up cases and find their contacts. At the moment, that’s incredibly operationally challenging […] because of the security situation.”
