WHO and IRC Warn Ebola Outbreak Could Become the Deadliest Ever Recorded

The Ebola outbreak tearing through eastern Democratic Republic of Congo became the third-largest on record barely a week after the world noticed it [1]. As of May 24, 2026, more than 1,010 suspected and confirmed cases and at least 231 deaths have been reported across DRC and Uganda [2][3]. The International Rescue Committee warned the outbreak "risks becoming the deadliest on record" [1], and WHO Director-General Tedros Adhanom Ghebreyesus acknowledged the epidemic is "outpacing us" [4].

What makes this outbreak categorically different from every major Ebola crisis of the past two decades is the pathogen itself: Bundibugyo virus, a rare species within the Ebola virus family for which there is no approved vaccine, no specific therapeutic, and no reliable rapid diagnostic [5][6].

The Numbers So Far — and the Benchmark to Beat

The deadliest Ebola outbreak in history struck West Africa from 2014 to 2016, infecting more than 28,600 people and killing at least 11,325 across Guinea, Liberia, and Sierra Leone [1][7]. The second-largest, in DRC's eastern provinces from 2018 to 2020, killed 2,299 [1]. The current outbreak, DRC's 17th, has already surpassed all but two previous outbreaks in just weeks [2].

Source: WHO / CDC

Data as of May 26, 2026CSV

The case fatality rate for Bundibugyo virus in prior outbreaks has ranged from 25% (Uganda, 2007) to 50% (DRC, 2012) [2][6]. If the current trajectory holds and the fatality rate approaches the higher end of that range, the outbreak would need roughly 22,650 cases to exceed the 2014–2016 death toll. Given that suspected cases surpassed 1,000 within approximately three weeks of public detection, epidemiologists fear the true scope is far larger — WHO officials believe the outbreak "probably began a couple of months ago" before being identified [8].

Source: WHO Situation Reports

Data as of May 26, 2026CSV

Where It Is Spreading

The epicenter is Ituri Province in northeastern DRC, where clusters of severe illness among healthcare workers at a hospital in Bunia Health Zone first raised alarms in early May [9][10]. From there, the outbreak has spread to Nord-Kivu and Sud-Kivu provinces. A confirmed case was identified in Goma, the North Kivu capital and a city of roughly two million people, after an infected woman traveled from Ituri [7]. One confirmed case was also found in Kinshasa, DRC's capital of over 17 million [7].

Across the border, Uganda reported seven confirmed cases in Kampala, including at least two healthcare workers and one death [4][8]. Italy briefly went on alert after two suspected cases in Lombardy tested negative [11].

Thirty days ago, the outbreak had not yet been formally declared. The speed of geographic expansion — from a single health zone in Ituri to three provinces and two countries in under a month — has outstripped the response at every stage [1][4]. Neighboring countries including South Sudan, Rwanda, Burundi, and the Republic of Congo are classified as high-risk by WHO, and the Africa CDC has declared a Public Health Emergency of Continental Security [12][13].

Why There Is No Vaccine — and When One Might Arrive

The two licensed Ebola vaccines — Merck's rVSV-ZEBOV (brand name Ervebo) and Johnson & Johnson's Zabdeno/Mvabea regimen — were developed against Zaire ebolavirus, the species responsible for the 2014–2016 and 2018–2020 outbreaks [6][14]. Bundibugyo virus, while a relative, has distinct surface proteins, meaning immunity generated by these vaccines does not reliably protect against the current strain [6][14].

Two candidate vaccines targeting Bundibugyo are in development. One uses the same rVSV platform as Merck's approved vaccine but reformulated for the Bundibugyo glycoprotein; no doses exist yet, and production is estimated to take six to nine months [14]. A second uses the ChAdOx adenoviral platform (the same technology behind the Oxford-AstraZeneca COVID-19 vaccine) and could produce initial doses in two to three months — but has no animal or human efficacy data [14].

Approximately 2,000 doses of the Zaire-targeted Ervebo are stockpiled in DRC. WHO experts are considering whether these could be deployed in a trial setting, but their use against Bundibugyo virus would be experimental, with no guarantee of protection [14]. The fastest realistic timeline for a proven, deployable Bundibugyo vaccine remains many months away.

Standard Ebola diagnostics also "struggle" to detect the Bundibugyo strain, which may have allowed the virus to circulate undetected for weeks before the outbreak was identified [1][5].

The Response Gap: Funding, Personnel, and Logistics

The outbreak has collided with a period of historic retrenchment in global health funding. The Trump administration's plan to close USAID includes $647 million in reductions for global health security programs and a broader $2 billion redirection from global health funding [15]. Aid workers in eastern DRC report that U.S.-funded healthcare workers have been laid off, medical supply procurement has shifted to the UN system, and protective equipment for frontline responders is scarce [15][16].

"The warning signs are flashing red," said Bob Kitchen, IRC vice president of emergencies. "Funding cuts and conflict have dismantled defenses at exactly the wrong moment" [1].

The withdrawal of U.S. funding to WHO prompted staff reductions at the organization, and no other donor has filled the gap [15]. The WHO's own flash appeal for the Ebola response has not been disclosed in full, but the IRC and other agencies report that pledged commitments from multiple donor governments remain unfulfilled [1][16].

On the ground, reaching affected communities is a logistical ordeal. The IRC reported that "it can take days to reach affected areas, with responders and supplies often having to traverse areas without roads, necessitating river travel" [17]. The Iran conflict has disrupted global shipping routes, increasing costs for medical supply procurement and forcing aid organizations to "reach fewer people because fuel and other supplies have gone up" [16]. Local markets in affected areas have been stripped of basic supplies — response teams are buying "all the soap and disinfectants available in the local markets" [16].

Conflict, Displacement, and the Collapse of Health Infrastructure

Eastern DRC has been engulfed in armed conflict for decades. Ituri and North Kivu provinces are home to more than two million internally displaced people and returnees [9][10]. The region recorded 5,800 protection incidents and 11 attacks against humanitarian actors in the period preceding the outbreak [9].

The affected population lives in conditions that accelerate Ebola transmission: dense displacement camps, inadequate water and sanitation, and minimal healthcare access. UNICEF reported that communities in the outbreak zone are "unable to buy soap" and living "without water" in "very close quarters" [16][18]. Healthcare capacity has been "weakened by lack of security and a shortage of health staff" [16].

Armed groups have directly impeded the response. A hospital in the outbreak zone was attacked, forcing the evacuation of patients under gunfire; 18 suspected Ebola patients were unaccounted for afterward [4]. Community distrust of outside authorities — rooted in decades of conflict and exploitation — is "significantly increasing the risk of disease transmission," according to WHO [4]. Families have clashed with responders over burial protocols, which require safe handling of highly infectious remains [4][16].

This mirrors the dynamics of the 2014–2016 West Africa outbreak, where weak health systems in post-conflict Liberia and Sierra Leone allowed the virus to run unchecked for months. The difference now is that the affected region of DRC has been in active conflict continuously, and international support infrastructure has contracted rather than expanded since 2020 [19].

Who Is Dying: The Demographic Burden

Healthcare workers were among the first victims. The index cluster in Bunia involved multiple hospital staff who fell ill before the pathogen was identified [9][10]. In the 2018–2020 DRC outbreak, healthcare workers accounted for a disproportionate share of infections due to inadequate protective equipment and late detection — a pattern now repeating [9].

Women bear a heavier burden of Ebola infection than men in DRC, driven by caregiving roles and patterns of daily activity that increase exposure [20]. Pregnant women face catastrophic outcomes: data from previous DRC outbreaks showed 89–93% maternal mortality and 100% fetal/neonatal mortality among infected pregnant women [20]. Children are also disproportionately affected [20].

The communities most exposed are those in displacement camps and rural health zones with no functioning clinic within walking distance. With over two million displaced people in the affected provinces, the population at immediate risk is vast and largely unreachable by the current response apparatus [9][18].

The Urban Threat: Goma and Beyond

The confirmation of Ebola cases in Goma (population approximately 2 million) and Kinshasa (population exceeding 17 million) represents what epidemiologists have long identified as the scenario most likely to transform a containable outbreak into a regional catastrophe [7][21].

Goma sits on the Rwandan border and serves as a major transit hub for eastern DRC. During the 2018–2020 outbreak, a single confirmed case in Goma prompted WHO to declare a public health emergency of international concern [7]. Kinshasa, connected to the rest of the continent and the world by Ndjili International Airport, is the node through which cross-border transmission could accelerate most rapidly.

WHO assessed the risk as "high at the national and regional levels, and low at the global level" [8]. Ten additional African countries beyond DRC and Uganda have been identified as at risk by the Africa CDC [13]. The U.S. CDC and Department of Homeland Security announced enhanced travel screening and entry restrictions on May 18 [12]. Epidemiological models for Ebola spread in dense urban settings are difficult to calibrate for the Bundibugyo strain specifically, given its rarity, but the 2014–2016 experience showed that once Ebola reaches a city with weak surveillance, case counts can double every two to three weeks [21][7].

Is the Alarm Premature? The Case for Caution

Not all observers agree that framing the outbreak as potentially "the deadliest ever" is helpful. WHO's own emergency committee, chaired by Lucille Blumberg, determined in May that "the current situation does not satisfy the criteria for a pandemic emergency" — a distinction one level above the current "public health emergency of international concern" designation [8].

Some public health officials have argued that extreme language risks triggering the same counterproductive responses seen in 2014: border closures that isolate affected communities, trade disruptions that cause food shortages, and international panic that diverts resources from the ground-level work of contact tracing and safe burial [8][19]. Secretary of State Marco Rubio criticized WHO as "a little late" in identifying the outbreak; Tedros countered that this reflected "lack of understanding of how IHR [International Health Regulations] work" [8].

Victor Dzau, president of the National Academy of Medicine, identified a "perplexing pattern of panic followed by neglect to take appropriate action" in global health responses [19]. The risk is that emergency declarations generate headlines but not sustained financing — the $4.5 billion in annual pandemic preparedness funding recommended after 2014 never materialized [19]. The counterargument is straightforward: with no vaccine, no treatment, active conflict, and a pathogen that may have spread undetected for months, the response is already behind, and the cost of under-reaction dwarfs the cost of over-reaction.

What Happens Next

The trajectory of this outbreak depends on variables that are partly epidemiological and partly political. Can vaccine candidates be accelerated into emergency use? Will donor governments restore or increase funding for the response? Can humanitarian access be secured in active conflict zones?

WHO has upgraded DRC's national risk assessment from "high" to "very high" [4]. Tedros warned the outbreak "will get worse before it gets better" [4]. The IRC's Heather Kerr, country director for DRC, put it plainly: "Every delay has a human cost" [1].

The 2014–2016 West Africa outbreak took over two years to contain, during which it infected more than 28,600 people — and that was with a known pathogen for which tools eventually became available. The 2026 outbreak involves a pathogen for which those tools do not yet exist, in a region where the health system is weaker, the population more displaced, and international support more fractured than at any point in recent memory.