East Africa Ebola Outbreak: The Race for a Vaccine Against the Bundibugyo Strain

East Africa’s Ebola outbreak is now sparking something bigger. It’s not just about containing the virus anymore. People are racing to develop tools against a new strain—one for which there still isn't any approved vaccine or treatment available.

This whole situation started with the Bundibugyo virus. That rare species of Ebola, it kicked off everything. The Africa Centres for Disease Control and Prevention first flagged it on May 15th in eastern Democratic Republic of the Congo. It spread quickly to Uganda. That’s worrying because those border communities are so connected, moving around constantly.

The World Health Organization jumped in fast. They called a public health emergency almost immediately. By June 2nd, they had confirmed at least 321 cases in the DRC alone. And some suspected ones too. The numbers were grim—48 deaths reported there, plus six recoveries. Uganda saw nine cases and one death on Tuesday. Then Kampala started reporting cases too, way away from that border line.

The Vaccine Challenge

But why is this so complicated? Why no vaccine for this specific Ebola strain?

The issue isn't just a simple lack of vaccines. It’s that the approved ones are for something else entirely. The Bundibugyo virus isn’t the same as the Zaire Ebola that caused all those big outbreaks back in 2014 and then again in the DRC. Zaire is the killer, you see. Much more lethal. Death rates there hit fifty to seventy percent.

The Bundibugyo strain still kills terribly—thirty to fifty percent. But that’s a different problem than what we dealt with before. You can't just slap an old vaccine onto this new virus without proper testing and approval first. There are only two main vaccines known for Zaire Ebola: Merck’s Ervebo, or Johnson & Johnson’s Zabdeno and Mvabea shots. But they don't work here directly.

Scientific Efforts and Vaccine Candidates

So what are scientists actually doing now? Things are moving in different directions.

The Coalition for Epidemic Preparedness Innovations—CEPI—pumped emergency money into three vaccine candidates. Think $3.2 million for IAVI, $50 million for Moderna, and $8.6 million for Oxford University. They’re all playing different games, using different platforms. None of them are ready to be deployed right now in the outbreak zone.

IAVI's candidate is being looked at by the WHO as the most promising shot. It uses the same basic tech as Ervebo. It’s the rVSV Bundibugyo vaccine. It works by using a harmless, weakened animal virus to teach the body what to fight. But there’s a delay. WHO expects it will take seven or nine months before doses are ready for actual trials. IAVI president Mark Feinberg is pushing hard to speed that up, trying to shorten this timeline.

Then you have the Oxford option. They're working with the Serum Institute of India on something called ChAdOx1 Bundibugyo. This uses a platform similar to that Covid jab—a modified chimpanzee cold virus delivered into the body. It might move faster than IAVI’s candidate. Some reports suggest trials could start within two or three months, but there’s still this hold-up. WHO experts insist they need more animal testing data before Greenlighting it.

Prof Teresa Lambe, from the Oxford team, said they were pushing hard even though they hoped the vaccine might not be needed at all. She told reporters they had started the animal studies and were moving fast with partners in the UK and the US to get those tests rolling.

Moderna is using mRNA technology. That’s a different approach entirely, something that got huge during Covid. They weren't on the initial WHO list because they were still assessing their response when the panel met. But Moderna is eager. Their chief executive Stéphane Bancel said they would move with urgency to bring a potential vaccine closer to people who need it most.

Treatments and Prevention

On treatments? Nothing approved yet for Bundibugyo Ebola specifically. Researchers are looking at existing medicines, though. They think three things might help. Two of them are monoclonal antibodies—MBP134 and Maftivimab. These mimic the immune system’s response. There’s also remdesivir, an antiviral drug floating around.

WHO independent experts actually recommended using MBP134 right now in the outbreak. Researchers are putting together a Partners trial to see which of these treatments works best against Bundibugyo Ebola. Amanda Rojek, who is leading that work at the Pandemic Sciences Institute, said the medicines exist and investigators are just waiting for regulatory sign-off from places like the DRC and Uganda.

She admitted there’s a big sticking point. You can have all the science ready on paper, but you still have to make sure it works safely in the field. She stressed that trials can't start until patients are getting good supportive care, and the teams are safe—especially in such a difficult zone. Evidence is everything.

For now, basic support remains the focus. Joanne Liu, an Ebola expert at McGill University, pointed out general treatment has to be about keeping people hydrated and managing blood pressure. It’s essentially supportive care, like handling flu symptoms.

And then there's prevention. Can a drug stop someone from getting infected after they’ve been exposed? Doctors are actually testing this now for the first time in an Ebola outbreak. They want to try obdeldesivir, an antiviral pill. The idea is to give it to anyone who has been exposed and see if it stops the disease from taking hold.

The results from animal studies were pretty strong according to The Guardian . Monkeys showed up to one hundred percent protection against two other Ebola strains when given the drug daily for ten days. But now the real test comes down to how fast field teams can identify contacts, follow them, and deliver that treatment effectively. Prof Christophe Fraser, who is involved in the Oxford trial, pointed out that speed depends on effectiveness and logistics. If the intervention isn't super effective, things just drag on longer.