The World Health Organization on Wednesday, November 4, backed clinical trials of two new Ebola vaccine candidates built specifically for the Bundibugyo virus, as health workers battle an outbreak in the Democratic Republic of Congo (DRC) and several other African countries that has killed more than 5,300 people — the deadliest and fastest-growing Ebola epidemic on record.

Source: AFP via MedicalXpress

"Today, WHO expert groups are recommending adding two vaccine candidates to the trial that had been developed specifically for the Bundibugyo virus," WHO Director-General Tedros Adhanom Ghebreyesus told reporters at a press conference in Geneva. The two candidates are ChAdOx1 BDBV, developed by the University of Oxford with the Serum Institute of India, and mRNA-1469, developed by the US biotechnology company Moderna. No vaccine has yet been approved against the Bundibugyo variant.

Source: Euronews / AFP

Regulators in Europe and Africa set out the ground rules for exactly these trials in October, favouring single-dose vaccines and a ring trial among close contacts of confirmed cases. Read the earlier report: regulators issue joint guidance to speed Bundibugyo Ebola vaccine trials

The scale of the emergency explains the urgency. On Monday, the Africa Centres for Disease Control and Prevention (Africa CDC) said Africa's ongoing Ebola epidemic had killed more than 5,300 people, the vast majority of them in the DRC, with 10,444 confirmed cases and a fatality rate of more than 50 percent. The outbreak began in the DRC in May.

Source: AFP / Africa CDC

10,444Confirmed Ebola cases reported by the Africa CDC on Monday
5,300+Deaths across Africa in the current epidemic, most of them in the DRC — Africa CDC
Over 50%Fatality rate in the current outbreak — Africa CDC
5,103Deaths reported in the DRC alone in the country's latest data, dated October 31 — via Euronews

Cases have also been reported in Kenya, Nigeria and Uganda, although the DRC remains the epicentre and the hardest-hit country, Euronews reported, describing the outbreak — on the DRC's own figures — as the fastest-growing and most widespread Ebola epidemic on record.

Source: Euronews

A trial that began with a vaccine built for a different virus

The candidates will join the Tumaini trial, which is led by the DRC's National Institute for Biomedical Research with support from WHO and international partners. The trial began in Bunia, in eastern DRC, on October 23, when the first participant was vaccinated — but the vaccine used first, Ervebo, is approved for the Zaire strain of Ebola virus, not for Bundibugyo, which is why the two purpose-built candidates matter. WHO's director of Science for Health, Dr Meg Doherty, explained when the trial began that it aims to identify one, two or three vaccines that could actually stop onward infection.

Source: NPR via KENW / AFP

Results will not come quickly. Trial results are expected in early 2027, and Dr Doherty said at the trial's launch that interim results were hoped for sometime at the beginning of 2027, with any wider rollout only after that if the data look promising.

Source: AFP / NPR via KENW

Tedros: vaccines are not a substitute for the basics

"Vaccines are powerful tools, but they are not substitutes for the proven measures that can save lives now: early care, contact tracing, isolation, safe and dignified burials and trusted engagement with communities," WHO chief Tedros Adhanom Ghebreyesus said on Wednesday.

Tedros also used the Geneva briefing to condemn travel restrictions imposed in response to the outbreak: some countries, including Ghana and the United States, have introduced restrictions on travellers arriving from the DRC, Euronews reported. "We call on countries that have imposed travel restrictions to lift them. Such restrictions punish countries for doing the right thing, create disincentives for transparency and harm the response," he said — a position the Africa CDC has also held since the beginning of the outbreak.

Source: Euronews

What is solid

  • WHO expert groups on November 4 recommended adding two Bundibugyo-specific vaccine candidates — Oxford/Serum Institute of India's ChAdOx1 BDBV and Moderna's mRNA-1469 — to the ongoing trial in the DRC — WHO chief Tedros Adhanom Ghebreyesus, via AFP and Euronews
  • No vaccine is approved against the Bundibugyo variant; the trial's first vaccine, Ervebo, is approved only for the Zaire strain — AFP / WHO
  • The Africa CDC put the epidemic at 10,444 confirmed cases and more than 5,300 deaths on Monday, with a fatality rate above 50 percent — AFP

What is only claimed

  • The exact death toll depends on the count and the date: the Africa CDC's Africa-wide figure exceeds 5,300, while the DRC's own data dated October 31 recorded 5,103 deaths in the DRC alone — the two figures cover different scopes and dates, and both are still rising

What happens next: the two candidates are expected to join the Tumaini trial once the remaining approvals are in place, alongside the Ervebo arm already under way in Bunia, with interim results hoped for in early 2027. Until then, the response in the DRC and its neighbours still rests on the measures Tedros listed — finding cases early, tracing contacts, isolating patients and burying the dead safely — in an outbreak that has already passed 10,000 cases.

Source: AFP / Euronews

Awaaz Punjab has been tracking the outbreak's rising toll in the Congo, where deaths passed 5,372 in the three-country count reported on November 3. Read: Congo's Ebola deaths pass 5,372 — still no vaccine for this strain