Two New Ebola Vaccines Undergo Clinical Trials

The World Health Organization (WHO) has recommended the expansion of Ebola treatment to include two new vaccine candidates, ChAdOx1 and mRNA-1469, developed by the University of Oxford and Moderna, respectively. These vaccines are designed to combat the Bundibugyo strain of Ebola, which was declared an epidemic in the Democratic Republic of Congo (DRC) in May 2026. The vaccines are part of the Tumaini project, which aims to test multiple vaccine candidates under a single trial using a ring vaccination approach.

The Tumaini project is a pioneering approach that was first adopted by the WHO and its partners during the Ebola outbreak in West Africa 10 years ago. The project involves recruiting contacts of individuals confirmed to have the Bundibugyo virus and testing the efficacy of vaccine candidates. The ChAdOx1 vaccine was developed by the University of Oxford in partnership with the Serum Institute of India, while the mRNA-1469 vaccine was developed by Moderna. Both vaccines have shown promising results in preclinical trials and early clinical data.

The WHO's independent technical advisory group, responsible for prioritizing vaccine candidates, has recommended that clinical evaluations continue for both ChAdOx1 and mRNA-1469. The group based its recommendation on available preclinical data and early clinical results. WHO Director-General, Dr. Tedros Adhanom Ghebreyesus, expressed enthusiasm for the development, stating that the vaccines' readiness for clinical trials demonstrates the power of science and partnership.

The clinical trials for the two vaccine candidates will be conducted in the DRC, where the Bundibugyo strain of Ebola is prevalent. The trials will assess the safety and efficacy of the vaccines in preventing Ebola infection. The WHO has been working closely with its partners, including the University of Oxford, Moderna, and the Serum Institute of India, to develop and test the vaccines.

The development of new Ebola vaccines is crucial in the fight against the disease, which has caused significant morbidity and mortality in Africa. The WHO has been working to expand treatment options for Ebola, including the use of vaccine candidates. The Tumaini project is an important initiative in this effort, as it allows for the testing of multiple vaccine candidates under a single trial.

The use of ring vaccination, as adopted in the Tumaini project, has been shown to be effective in controlling Ebola outbreaks. The approach involves vaccinating individuals who have come into contact with someone infected with the virus, thereby preventing further transmission. The WHO and its partners have been working to implement this approach in the DRC and other affected countries.

The clinical trials for ChAdOx1 and mRNA-1469 are expected to provide valuable insights into the safety and efficacy of these vaccine candidates. The WHO will continue to work with its partners to monitor the trials and assess the results. If successful, the vaccines could provide a critical tool in the fight against Ebola, helping to prevent and control outbreaks in affected countries.

Key points

• The WHO has recommended the expansion of Ebola treatment to include two new vaccine candidates, ChAdOx1 and mRNA-1469.
• The vaccines are part of the Tumaini project, which aims to test multiple vaccine candidates under a single trial using a ring vaccination approach.
• The clinical trials for the vaccine candidates will be conducted in the Democratic Republic of Congo, where the Bundibugyo strain of Ebola is prevalent.