Bundibugyo Ebola outbreak spreads to Uganda as vaccine race accelerates with $60m funding

The outbreak's toll

The Bundibugyo strain of Ebola, first confirmed in the Democratic Republic of the Congo's Ituri province on May 15, has now spread to neighbouring Uganda. As of June 2, the WHO reported 321 confirmed cases in the DRC, with 48 confirmed deaths. Uganda's health ministry confirmed six new cases on Tuesday, bringing its total to 15 confirmed cases and one death. The Africa Centres for Disease Control and Prevention announced the outbreak, Congo's 17th, on May 15, and the WHO swiftly declared it a public health emergency of international concern.

The true extent of the outbreak remains difficult to assess. Extremely limited testing capacity and difficulties accessing certain areas necessitate interpreting these figures with caution.

The number of suspected cases dropped sharply from 906 to 116 after hundreds were ruled out following investigation. However, the International Rescue Committee warned the outbreak was probably significantly larger and more advanced than official figures suggested, with the virus possibly spreading for up to three months before the first official cases were detected in mid-May.

Cross-border spread and containment challenges

Uganda has closed its border with Congo to limit the virus's spread, but the UN International Organization for Migration warned this may push people towards less monitored informal crossing points, increasing the risk of further transmission. IOM monitoring data showed people were still crossing borders, reinforcing the need for regional coordination rather than isolated national measures.

The confirmation of cross-border transmission of the virus in the DRC and Uganda is a stark reminder that disease surveillance is only as strong as the weakest point along a shared border.

Alan Kasujja, a Uganda government spokesperson, said the government was trying to protect its citizens and that communities along the borders were sensitized on the Ebola situation. In the DRC, contact tracing remains a critical gap. WHO Director-General Tedros Adhanom Ghebreyesus said only about 45% of contacts have been followed up, well short of the 90% target needed to get ahead of the outbreak.

Security and access obstacles

Armed groups active in eastern DRC, including the Rwanda-backed M23 rebel group and the Islamic State-allied Allied Democratic Forces, have created a huge and vulnerable displaced population. Some Ebola treatment centres have been attacked by wary residents. Congo's government had suspended passenger flights to Bunia, the main airport in Ituri, but reversed that decision late on Monday, announcing a gradual and safe resumption of air transport with mandatory temperature screening and hand washing for all passengers.

The vaccine and treatment race

There are no approved vaccines or treatments for the Bundibugyo strain, which has a fatality rate of up to 40%. The Coalition for Epidemic Preparedness Innovations (CEPI) announced roughly $60 million in emergency funding on Monday to accelerate the development of shots against the virus. The funding goes to Moderna and two other groups.

Every day counts in the race against this deadly disease.

The WHO has recommended prioritizing several experimental candidates. The most promising vaccine candidate is a single-dose rVSV Bundibugyo vaccine being developed by the International AIDS Vaccine Initiative, which uses the same technology as Merck's approved Ervebo vaccine for the Zaire strain. Development will likely take seven to nine months before it is ready for assessment in a clinical trial. CEPI has committed an initial $3.2 million to advance this candidate. Another priority candidate, ChAdOx1 Bundibugyo, is being developed by Oxford University and the Serum Institute of India, based on the technology used in the Oxford/AstraZeneca COVID-19 vaccine.

It's difficult to have an effective vaccine that adheres to the scientific protocol available quickly.

At least five people have recovered from the virus in the DRC, offering rare signs of hope amid the outbreak.