Inside the study for a remedy to fight Congo’s deadliest Ebola outbreak

Experimental Ebola Pill Trial Begins in Eastern Congo

Earthguardiansonline.com – Health teams in eastern Congo are testing an experimental antiviral pill that may help prevent Ebola illness after a person has been exposed to the virus. More than 250 people have joined the study so far, a major effort during what has become the country’s deadliest Ebola outbreak.

The trial focuses on the Bundibugyo virus, the strain driving the rapidly expanding emergency. Unlike other Ebola strains, Bundibugyo currently has no approved vaccine or treatment specifically designed for it. The outbreak was declared in mid-May and has since reached seven provinces, with at least 8,300 confirmed infections and 4,000 deaths.

Its pace has strained efforts to identify exposed people, follow their health and contain new chains of transmission. The study underway in Ituri province, the center of the outbreak, is intended to offer another tool while broader control measures continue.

A preventive treatment after exposure

Researchers are evaluating obeldesivir, an investigational antiviral pill made by Gilead. Participants take it shortly after a suspected encounter with Ebola, before they have symptoms, in the hope that infection will not progress into disease.

This strategy is known as post-exposure prophylaxis, or PEP. It is different from vaccination, which can require time before meaningful protection develops, and it is not a treatment for patients already showing Ebola symptoms.

“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,” ALIMA research coordinator Dr. Guilavogui Jean Paul Yassa said.

The study is coordinated by ALIMA, a medical nonprofit, alongside Congo’s National Institute of Biomedical Research and the French institute ANRS Emerging Infectious Diseases. Researchers aim to enroll nearly 1,000 adults and children aged 12 and older who have been in contact with a confirmed Ebola patient within the previous five days.

To measure whether the medicine works, half of the participants receive a placebo. Everyone enrolled must have no symptoms at the time they enter the study. Medical teams see participants daily for 21 days, then conduct a final telephone follow-up after 42 days, said Dr. Godefroid Basara, who works on the trial.

Families and health workers among participants

People at the trial center include relatives of patients and health workers who may have been exposed while caring for others. Some participants asked not to be identified because of the personal and sensitive circumstances surrounding their involvement.

One woman joined the trial in August after her husband tested positive. She described direct contact with him and with his vomit, leaving her fearful that she might have been infected herself and could potentially expose others.

“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,” the participant said.

She said her family had not developed symptoms since entering the study. She also knew of households in which multiple people became infected after one relative tested positive.

Ebola spreads when an infected person has developed symptoms. That makes rapid identification of close contacts especially important, because people who may have been exposed must be monitored while they wait to learn whether they will become ill. In this outbreak, locating people who could be incubating the Bundibugyo virus has been particularly difficult.

Another participant said two relatives had contracted Ebola and that one had died.

“This disease is killing. It’s better to take precautions,” he said.

Challenges beyond the medicine

Even an effective preventive pill would need to reach people quickly to interrupt transmission. The five-day eligibility window means that contact tracing, communication and transport are central to the study’s success.

Dr. Jacques Zawadi, an investigating physician working with ALIMA at the trial center, said many people are willing to participate. Reaching those who live farther away, however, has made enrollment more difficult.

Grief can also interrupt participation. Some people learn that a family member has died while they are enrolled and then struggle to return for continued monitoring.

“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,” he said.

If a participant develops symptoms, ALIMA says supportive medical care will begin immediately. Early supportive treatment can be beneficial, and the study teams are monitoring participants closely so that symptoms can be recognized without delay.

Vaccination effort continues

Congo has also begun vaccinating health workers with Ervebo, a vaccine that proved effective in earlier outbreaks caused by a different and more common Ebola virus. Authorities have said it may provide some degree of protection against Bundibugyo, although research is still examining whether it can prevent illness from this strain.

New vaccines for Bundibugyo are being developed elsewhere, but the current outbreak has created an urgent need for measures that can be used now. The obeldesivir trial could help determine whether prompt medication after exposure can add a practical layer of protection for households, caregivers and others facing high-risk contact.

If the pill succeeds, it could help sever infection chains before people become sick, offering a potentially valuable option in communities where the outbreak continues to move faster than containment efforts.