Ebola vaccine trial begins in DR Congo

The World Health Organisation (WHO) on Monday said 20,000 doses of the Ervebo vaccine had been allocated for a research vaccination programme in Ituri province of the Democratic Republic of Congo (DRC).

The Ebola vaccine trial is underway in the DRC is involving frontline health workers and others involved in the response.

The trial is aimed at improving understanding of how effective the vaccine is against Ebola Bundibugyo virus – and to protect individuals most exposed to it.

The Ervebo vaccine has been “highly effective” against Ebola Zaire virus in the past, but it is not yet known whether it can provide “meaningful protection” against Ebola Bundibugyo disease, which is still spreading in the DRC.

A total of 70,000 doses have been made available to the Congolese authorities to support the outbreak response and related research.

The epicentre of the outbreak remains Ituri province in eastern DR Congo, although the virus has spread to seven provinces since it was confirmed in May this year.

Those leading the outbreak response face many challenges related to an ongoing humanitarian emergency caused by decades of violence in the DRC’s vast, resource-rich eastern provinces.

In January 2025, Rwanda-backed M23 militia seized control of Goma, capital of North Kivu province, before going on to take Bukavu, capital of South Kivu, weeks later.

In support of the DRC authorities, WHO continues to strengthen surveillance of Ebola infection and transmission, conduct contact tracing, boost clinical preparedness and management, and ensure the delivery of supplies.

The UN agency also supports community engagement and cross-border preparedness.

“Community engagement will be key. It is only when communities are engaged in the response that such outbreaks are brought under control,” the WHO stressed.

Latest health authority data indicates a total of more than 7,600 confirmed cases of infection, including over 3,670 deaths, with nearly eight in 10 infections recorded in Ituri.

Ervebo is the only Ebola vaccine licensed for use during outbreaks caused by the Bundibugyo virus.

The WHO-backed panel, which advises on vaccines, recommended earlier this month that Ervebo should only be used for research purposes initially.

It also emphasised that the vaccine’s “unknown efficacy” against Bundibugyo virus should be clearly communicated, although limited data and anecdotal reports suggest that Ervebo may provide “some protection” against the disease.

Ebola disease is a severe, often fatal illness affecting humans and other primates.

The virus is transmitted to people from wild animals (such as fruit bats, porcupines and non-human primates); it then spreads in the human population through direct contact with the blood, secretions, organs or other bodily fluids of infected people.

It can also be transmitted by contact with bedding or clothing contaminated with these fluids.

The average Ebola disease case fatality rate is around 50 per cent, according to WHO. Case fatality rates have varied from 25 to 90 per cent in past outbreaks.

The first Ebola disease outbreaks occurred in remote villages in Central Africa, near tropical rainforests.

The 2014–2016 Ebola virus disease outbreak in West Africa was the largest and most complex Ebola outbreak since the virus was first discovered in 1976.

There were more cases and deaths in this outbreak than in all others combined. It also spread between countries, starting in Guinea, then moving across land borders to Sierra Leone and Liberia.