Ebola in DRC: Suspected cases plummet, but WHO urges caution

Official figures remain grim: in eastern Democratic Republic of Congo, authorities have confirmed 321 laboratory-confirmed Ebola virus infections, of which 48 were fatal. In Uganda, as reported by the Ministry of Health, 6 new cases have been registered, bringing the total to 15 laboratory-confirmed infections since the beginning of the epidemic in the neighboring country, with one death already reported.

WHO spokesperson Lindmeier emphasized that, although the figure is apparently positive, it is still too early to conclude that the epidemic is being managed more effectively. In hundreds of cases initially registered as suspected due to symptoms, the Ebola infection was not subsequently confirmed by tests, which partly explains the sharp reduction in the count.

A Rare Variant Without Specific Tools

Lindmeier, however, clarified that a high number of suspected cases can also be interpreted as a positive sign: it means the detection system is working and that people with symptoms are presenting themselves to health facilities. The WHO has assumed since the epidemic was identified in eastern Congo in mid-May that the actual number of infections is significantly higher than officially recorded.

The epidemic is caused by the rare Bundibugyo variant of the Ebola virus, first discovered in 2007. This is only the third outbreak of this type ever documented in history. Unlike the more common Zaire variant, for which vaccines and therapies exist, no vaccines, specific drugs, or rapid diagnostic tests are currently authorized for the Bundibugyo strain.

The Ebola virus is transmitted through physical contact and bodily fluids of infected individuals. The mortality rate of the Bundibugyo variant is between 30 and 50 percent. The WHO and Africa CDC have described this outbreak as one of the most difficult Ebola epidemics in recent years, with several hundred deaths already recorded.

The outbreak went unnoticed for weeks in the Ituri province, bordering Uganda and South Sudan, and not all cases are being reported. This delay in detection has complicated containment efforts and favored the spread of the virus in an area already fragile from a health perspective.

The Search for a Vaccine Against Bundibugyo

On the research front, news is not encouraging in the short term. The VSV-Ebov vaccine, approved in 2019 and developed with the participation of German researcher Marylyn Addo from the University Medical Center Hamburg-Eppendorf, is effective against the Zaire variant but not against Bundibugyo. During the coronavirus pandemic, almost all resources allocated to Ebola were diverted to the pandemic response, slowing down vaccine development for other strains.

Marylyn Addo recalled the complexity of the challenge: "Wir haben sechs Ebola-Spezies, vier davon infizieren Menschen. ... aber warum hat man gegen die anderen drei nicht einen Impfstoff? Da muss man ganz klar sagen, in einer perfekten Welt, wo Ressourcen keinen Rolle spielen, hätten wir den Impfstoff schon."

A few years ago, researchers at the University of Texas demonstrated that the VSV-Ebov vaccine could be adapted to the Bundibugyo strain. Addo described this prospect as promising: "Wir gehen davon aus, dass das ein vielversprechender Kandidat ist, weil man den nur einmal verimpfen muss. Außerdem wissen wir, wie man das in einer Ring-Vakzinierung anwendet." Ring vaccination, which involves immunizing all individuals who have come into contact with an infected person, has proven very effective in previous epidemics.

Obeldesivir: The Hope of an Oral Antiviral

On the drug front, the WHO has announced that studies on post-exposure prophylaxis with Obeldesivir, an oral antiviral developed from Remdesivir, will begin shortly. Remdesivir, during the coronavirus pandemic, could only be administered intravenously. Tests of Obeldesivir against the Zaire variant did not yield conclusive results, but animal studies have shown good results against Bundibugyo.

Authorities in the affected countries and regions are currently negotiating the exact conditions for the clinical study on Obeldesivir. The WHO and the scientific community consider the drug a source of hope for mitigating the current epidemic, provided it is administered very early after contact with an infected person.

Several international funders, including CEPI, the Gavi vaccine alliance, and the World Bank's pandemic fund, have announced grants in the millions for research into Ebola vaccines. The funds should enable promising candidates to be tested in humans within a few months.

Comparison with Previous Epidemics

At Leipzig University, Professor Clara Schoeder is working with Oxford University on a viral vector vaccine, similar to the one developed by AstraZeneca against coronavirus. The goal is a pan-vaccine capable of protecting not only against Bundibugyo but also against other filoviruses such as Marburg virus. The research, which began only last year, is still in its very early stages, and the specific preparation has not yet been tested in humans.

Filoviruses cause hemorrhagic fever with internal and external bleeding and are known for their high mortality rate. Stephan Becker, director of the Institute of Virology at the University Hospital of Marburg, warned that the current situation is reminiscent of the 2013-2014 Ebola epidemic in West Africa: "Eine klinische Prüfung hat noch nicht stattgefunden und das heißt, wir sind in einer sehr ähnlichen Situation wie 2013/2014 bei dem Ebola-Ausbruch in Westafrika."

To contextualize the scale of the ongoing epidemic, historical data is impressive: the major Ebola epidemic in West Africa in 2014-2016, caused by the Zaire strain, killed at least 11,000 people. The second-deadliest outbreak ever recorded, between 2018 and 2020 in eastern Congo, caused about 2,300 deaths. During the coronavirus pandemic, the concept on which the VSV-Ebov vaccine is based was shown to be effective and well-tolerated.

Prospects and Unknowns for the Coming Weeks

According to the information released, this news was broadcast on June 2, 2026, on Deutschlandfunk: "Diese Nachricht wurde am 02.06.2026 im Programm Deutschlandfunk gesendet." The WHO spokesperson reiterated that only the analysis of the coming weeks will reveal whether the decline in suspected cases reflects an actual containment of the epidemic or if it is due to transient factors in testing and surveillance capacity. "Studio KURIER" – everywhere podcasts are available and also on YouTube as a video podcast.

Meanwhile, health teams continue to operate in a context marked by limited infrastructure, porous borders, and a viral variant for which, unlike Ebola Zaire, the therapeutic and preventive arsenal is still under development. The speed at which clinical results will emerge for vaccine candidates and Obeldesivir will be decisive for the international response in the coming weeks.