ITURI PROVINCE — More than 250 participants have enrolled in the EBO-PEP clinical trial to test an experimental drug for preventing Ebola infection. The study is evaluating Gilead’s obeldesivir as post-exposure prophylaxis against the Bundibugyo virus in the eastern province of Ituri.

The trial aims to recruit nearly 1,000 adults or children over the age of 12 who have had contact with a confirmed case within the last five days but show no symptoms. Half of these participants will receive a placebo while the other half receives the antiviral pill. Researchers monitor participants in person every day for 21 days, followed by a final phone call after 42 days.

ALIMA coordinates the trial alongside Congo’s National Institute of Biomedical Research (INRB) and the French institute ANRS Emerging Infectious Diseases. The INRB in Kinshasa serves as a co-sponsor with ANRS MIE / Inserm. The study operates at two centers in Ituri province, including Rwampara Hospital and the Evangelical Medical center in Bunia. An additional compassionate use cohort has enrolled children under 12 and high-risk pregnant or breastfeeding women.

The drug targets the Bundibugyo virus, which causes the current outbreak and has no approved vaccine or treatment. The World Health Organization has recommended evaluating post-exposure prophylaxis strategies, including obeldesivir, as a key measure to prevent the spread of the virus. ALIMA Research Coordinator Dr. Guilavogui Jean Paul Yassa explained the distinction between this approach and other medical interventions.

"It differs from a vaccine, which may take days or weeks to provide protection. It is also different from curative treatment because it is intended for people who are not yet showing symptoms."

Participants view the trial as a necessary precaution given the lack of approved treatments. One participant described the fear of transmission after caring for a sick family member. "I realized that if I even touched my husband — and I did touch him, his vomit, everything — (it meant that) I was a direct contact. I could have also passed on this contagious disease. I could have been contaminated." Another participant emphasized the urgency of the situation.

"This disease is killing. It’s better to take precautions."

Investigating Physician Jacques Zawadi noted that emotional distress among contacts poses a logistical challenge for the study. "This is the biggest challenge we face. When a person is emotionally affected, it is not easy to reason with them and ensure they return to the study," Zawadi said.

"To identify a medication, to treat a disease that does not have medication, this gives hope. Most of the participants are happy to be with us and to be able to benefit from this treatment, although it is still a trial," Zawadi said.

The broader outbreak context remains severe. At least 8,300 confirmed Ebola cases have been recorded since the outbreak was declared in mid-May 2026. At least 4,018 deaths have been recorded from the epidemic.

The disease has spread to seven provinces in Congo. The World Health Organization stated the outbreak is set to exceed the West Africa regional outbreak between 2014 and 2016, which killed 11,000 people. As of 9 July 2026, 600 people had died and 1,759 had been infected in the DRC and Uganda, according to the DRC's National Institute of Public Health (INSP).

Health system strains accompany the viral spread. At least 50 health workers have died after contracting Ebola. An ALIMA humanitarian physician tested positive for Ebola in June 2026 after returning to France.

Congo has started vaccinating health workers with the Ervebo vaccine. However, labor disputes have arisen, as health workers in Bunia protested unpaid wages for August and September 2026. Security incidents have also disrupted care, such as when soldiers burned an Ebola-hit displacement camp in Kigonze on 30 September 2026, forcing 19,000 people to flee.

Timeline

The EBO-PEP trial was launched in response to the 2026 Ebola outbreak caused by the Bundibugyo virus, which was declared a public health emergency of international concern by the World Health Organization on 17 May 2026. The EBO-PEP trial began in July 2026.

As of 9 July 2026, 600 people had died and 1,759 had been infected in the current Bundibugyo Ebola outbreak in the DRC and Uganda, according to the DRC's National Institute of Public Health (INSP). The EBO-PEP trial, which began on 14 July 2026, has enrolled over 200 participants as of 14 September 2026, according to the EBO-PEP website. The EBO-PEP trial reached the 200-enrolment milestone on 14 September 2026, with 204 participants enrolled as of that date. Soldiers burned an Ebola-hit displacement camp housing a transit center for infected patients in Kigonze, forcing 19,000 people to flee on 30 September 2026.

What's New

The EBO-PEP trial was initially planned to begin in 2024, but was launched in July 2026 due to the urgent need to address the ongoing Bundibugyo Ebola outbreak. The EBO-PEP trial is part of a platform trial designed to evaluate multiple antiviral drugs for post-exposure prophylaxis against filoviruses, including the Bundibugyo virus.

Why It Matters

The EBO-PEP trial represents a critical response to an outbreak caused by a virus with no approved vaccine or treatment. The World Health Organization has identified post-exposure prophylaxis as a key measure to prevent the spread of the Bundibugyo virus. With at least 4,018 deaths recorded and the outbreak spreading to seven provinces, the scale of the crisis exceeds previous regional epidemics. The trial’s design allows for the evaluation of obeldesivir in a real-world setting, providing data that could inform future outbreak responses.

Security instability and resource constraints complicate the public health effort. The burning of a displacement camp in Kigonze and protests by unpaid health workers illustrate the fragile environment in which the trial operates. Despite these challenges, the enrollment of more than 250 participants demonstrates a willingness among exposed contacts to engage with experimental prevention methods. The outcome of the study could establish a new standard for protecting high-risk individuals during filovirus outbreaks.