Ebola Vaccine Trial Begins in DR Congo: Ervebo to Be Tested Against Bundibugyo Virus

The Democratic Republic of Congo, which is also referred to as the DR Congo, has started the its Tumaini clinical study on October 23, 2026, to find out if the vaccines that already exist or are being developed offer protection from the Bundibugyo strain of the Ebola virus. The first vaccination of the Ervebo vaccine started in Bunia, which is a city in northeastern Ituri Province. This study is being conducted with the help of the World Health Organization (WHO).

Introduction to the Tumaini Study

“Tumaini” is the word for “Hope” in Swahili. This is a trial that seeks to test multiple vaccines against the Bundibugyo virus under the same umbrella. The study is spearheaded by the health department of the DR Congo and co-sponsored by the INRB and the Global Health Institute of the University of Antwerp.

Some of the objectives of the trial include the,

• Safety: Does the vaccine have any negative effects?
• Immunogenicity: Is the vaccine capable of inducing an immune response?
• Efficacy: Can the vaccine confer protection against the disease?

The first administration was done in Bunia on October 23, 2026 using Ervebo vaccine.

Why Is Ervebo Being Used In Testing For Bundibugyo Virus?

Ervebo is a licensed vaccine which prevents Ebola virus disease due to the Ebola virus species called Zaire. However, the current outbreak in DR Congo is due to Bundibugyo virus, a different species.

There is currently no licensed vaccine available for the prevention of Bundibugyo virus disease. Animal experiments indicate that Ervebo might be able to give some degree of cross-protection.

However, the effectiveness of Ervebo against Bundibugyo virus disease in human subjects is yet unknown. WHO recommends using the vaccine only under the framework of research.

The study is important in that it would show whether the vaccine which is currently available can provide protection until vaccines for Bundibugyo virus are developed.

Tumaini Trial Evaluating Two Bundibugyo-specific Vaccine Candidates

The Tumaini trial is set to evaluate two other candidates that are based on various technologies.

Vaccine candidate	Developer	Technology
ChAdOx1 Bundibugyo vaccine	University of Oxford, Serum Institute of India	Adenoviral vector
mRNA-1469	Moderna	mRNA technology

Both vaccine candidates have been supported by the Coalition for Epidemic Preparedness Innovations (CEPI) and have been subjected to early-stage clinical trials, subject to approval for participation in Tumaini trial.

What is Ring Vaccination?

Ring vaccination is a public health intervention approach that targets individuals with high probability of being exposed to an infected individual. As opposed to vaccinating everyone in a community, the health authorities target contacts of infected persons and if appropriate, contacts of contacts.

The use of this intervention strategy in the Tumaini study will help to evaluate the efficacy of the vaccine in the most exposed population.

Definition of Ebola Disease

This is a serious illness caused by Orthoebolavirus viral infections. This may cause such symptoms as fever, weakness, vomiting, diarrhea and bleeding from the eyes, nose, gums and even from other body openings in extreme cases.

Transmission occurs through coming into contact with the blood or any other body fluids of someone infected with the disease who is symptomatic or has died. The disease is not usually transmitted through the air as is the case with measles.