WHO adds two experimental Ebola vaccines to the clinical trial in Congo

The World Health Organization (WHO) announced that two new experimental Ebola vaccines will join the Tumaini clinical trial underway in the Democratic Republic of Congo, in what will be the first time vaccines designed specifically against the Bundibugyo variant, responsible for the current epidemic, are tested during an outbreak.

The two formulas are ChAdOx1, developed by the University of Oxford together with the Serum Institute of India, and mRNA-1469, from the drugmaker Moderna. An independent WHO advisory group recommended both for further evaluation based on preclinical and early clinical evidence, and they will join the trial once national approvals are in place.

The Tumaini trial —"hope" in Swahili— is a phase 2/3 study led by Congo's National Institute for Biomedical Research with the University of Antwerp and the collaboration of WHO, Médecins Sans Frontières and Africa CDC. It uses ring vaccination: the contacts of people with confirmed cases, and the contacts of those contacts, are vaccinated. The first vaccine being tested is Ervebo, licensed against the Zaire strain, to determine whether it offers cross-protection against Bundibugyo; four vaccination rings are already underway, following the first doses given in Bunia, capital of Ituri province, in late October.

The outbreak, declared on May 15, has reached more than 10,000 confirmed cases and nearly 5,000 deaths, according to WHO. There is no approved vaccine or treatment against the Bundibugyo variant. Results from the vaccine trial are expected in early 2027, while the first findings on treatments —a monoclonal antibody and the antiviral remdesivir— should arrive in the coming months.

The announcement comes days after a British doctor infected during the outbreak was evacuated from Congo to a hospital in London, as A Lo Claro reported this morning.

Photo: WHO

Source: World Health Organization