Bundibugyo virus — one of six Ebola strains — appeared in the DRC's Ituri Province in May 2026 and spread to Uganda. WHO declared a public health emergency of international concern on May 16. As of July 12, there were 1,926 confirmed cases and 702 deaths in DRC, plus more than 20 in Uganda. WHO estimates the real caseload could be 4,000 to 8,000. Confirmed cases are only a fraction of that — contact tracing is failing, and four out of five new cases have no known link to prior patients. Wessam Mankoula, head of emergency preparedness and response at Africa CDC, called it "the fastest-growing Ebola outbreak ever, not only among the previous Bundibugyo outbreaks, but all the different viruses that are causing Ebola." There is no approved vaccine or treatment for the Bundibugyo strain.

1. Try the Existing Vaccine Now (IAVI / Mark Feinberg)

Some researchers say the severity justifies using what's available — even if it's designed for a different Ebola strain.

A proven vaccine exists — just for a different strain. Mark Feinberg, president and CEO of IAVI, is pushing for a "prime-boost" strategy: give the approved Zaire-strain vaccine first to prime the immune system, then follow with a Bundibugyo-specific booster. He said the approach would be "worthwhile given the severity of the situation and the lack of available Bundibugyo-specific medical countermeasures." The Bundibugyo-specific candidates won't be trial-ready for months: CEPI announced emergency funding to fast-track vaccines from IAVI ($3.2M), Moderna ($50M), and the University of Oxford ($8.6M), but those candidates are still in early development.

People are dying while researchers wait for a perfect tool. Feinberg argues that partial cross-protection is still worth acting on: deploying the Zaire vaccine now could save lives that would otherwise be lost before Bundibugyo-specific options reach the field.

2. Wait for the Right Tools — and Run the Treatment Trials (WHO, César Muñoz-Fontela, Beth-Ann Coller)

Using the wrong-strain vaccine could produce misleading data and damage confidence in the tools that actually work.

WHO already made the call: don't use the Zaire-strain vaccine here. On May 28, WHO officially recommended against rVSV-ZEBOV — the approved Zaire Ebola vaccine — for this outbreak, citing low evidence that it provides cross-protection against Bundibugyo. César Muñoz-Fontela, a viral immunologist at the Bernhard Nocht Institute for Tropical Medicine, said "You need to have really, really compelling scientific information" before testing the prime-boost strategy. He warned that a failed trial could undermine global trust in the Zaire vaccine for future outbreaks. Beth-Ann Coller, who was executive director of global clinical development at Merck when the company brought the Zaire vaccine to market, shares those reservations.

The right move is running proper treatment trials. WHO's PARTNERS trial enrolled its first patient on July 2 — the first-ever randomized controlled trial testing treatments for Bundibugyo virus disease. It's evaluating remdesivir and MBP134, a monoclonal antibody, separately and in combination. A parallel trial called EBO-PEP is testing obeldesivir, an oral antiviral made by Gilead Sciences, as a post-exposure preventive for high-risk contacts. Results from a properly run trial can reach patients beyond this outbreak.

3. The Infrastructure Was Already Gone (Samantha Power, Josh Michaud / KFF, MSF)

The outbreak is this bad because the infrastructure to stop it was already gutted before the first case appeared.

The US pulled back before the outbreak even started. The Trump administration dissolved USAID, cut CDC staffing, and withdrew US funding from WHO. It also reduced health aid to DRC and Uganda. Former USAID administrator Samantha Power said on Bloomberg: "I don't believe we would have a spiraling Ebola epidemic if USAID had not been dismantled." USAID-funded PPE — gloves, body bags, basic protective equipment — isn't reaching Ituri Province because the supply chains USAID maintained no longer exist.

The $518M response plan is barely a third funded. Africa CDC and WHO launched a six-month response plan requiring that full amount. WHO's own emergency appeal, targeting $115M, was at 32% funded as of early July. Josh Michaud, associate director for global and public health policy at KFF, said: "When you add up all of those elements, it's hard to see how there could not have been an effect on the surveillance and response capacities in these countries." MSF, which has more than 1,400 staff on the ground in DRC and Uganda, warned that "dangerous gaps persist" in surveillance, diagnosis, contact tracing, and community engagement.

Partners In Health went further. Dr. Loune Viaud Casséus, a physician with Partners In Health, called this "the first outbreak of the post-USAID era" — arguing that USAID funded the surveillance infrastructure behind every previous DRC Ebola response, and that infrastructure is now gone.

Where This Lands

Feinberg and IAVI want to use what's available now, even imperfectly. Muñoz-Fontela and WHO are holding out for rigorous science — and the PARTNERS treatment trial is their live bet on saving lives before Bundibugyo-specific vaccines arrive. The funding camp argues none of it matters much until the $518M response plan is actually funded. The outbreak is already outpacing the response — four out of five new cases are appearing without traceable contacts. The US extended its entry ban for foreign nationals from DRC, Uganda, and South Sudan on July 13, effective through at least July 21. The PARTNERS trial just enrolled its first patients two weeks ago, testing the first-ever treatments for Bundibugyo. Its results will be the first real data point in a debate that's otherwise running on theory and urgency.

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