The Democratic Republic of the Congo's Ebola outbreak is "growing exponentially," the United Nations' senior Ebola coordinator said Friday, with more than 2,500 deaths recorded — half of them in the last 20 days.

Julien Harneis told reporters from Bunia, the epicentre in Ituri province, that the disease is now spreading across an area larger than France. "It is growing faster and wider than the Ebola response," he said, urging a rapid scale-up of staffing and resources.

The warning came as the first batch of more than 16,000 Ervebo vaccine doses arrived in Kinshasa late Friday, with a total of 70,000 doses pledged by the World Health Organisation (WHO) and partners. Twenty thousand of those doses are earmarked for a clinical trial to assess the vaccine's effectiveness against the Bundibugyo strain, and 50,000 will go to front-line and health workers.

An outbreak that keeps speeding up

The DRC declared the outbreak on May 15 — the country's 17th — but it is believed to have been spreading for weeks beforehand. The first suspected cases were detected on 24 April. The current epidemic, which has hit regions with weak state presence, poor health infrastructure and armed-group activity, has already become the deadliest in DRC history and the second-largest on record globally, behind only the 2014-2016 West Africa epidemic.

Latest health authority data, published Friday, put the death toll at 2,516 among 5,290 confirmed cases, according to the WHO. The overall case fatality rate is 47.6 percent. A separate count issued Saturday by the country's public health authorities records 5,375 confirmed cases and 2,557 deaths as of Thursday. Harneis said half of all deaths occurred in just the last 20 days.

Officials describe the outbreak as the fastest-spreading on record, with about one person dying every 30 minutes.

"This epidemic continues to spread, moving faster than the response can keep up," MSF president Javid Abdelmoneim said in a statement, while MSF cautioned that the outbreak was spreading at an 'alarming rate'.

The burden falls heavily on the eastern provinces. Ituri remains the epicentre, accounting for more than 4,000 confirmed cases. In the latest 24-hour reporting period, authorities recorded 101 new cases and 53 deaths. More than 70 percent of deaths are occurring in communities rather than in treatment centres, according to health officials.

A response under assault

Healthcare workers are among the hardest hit. Around 160 have contracted Ebola and 43 have died. Attacks against health workers have included arson and stoning of ambulances, with more than 260 such attacks in the past six months and eight deaths reported. Harneis said that workers faced "extremely difficult" conditions.

Funding is also perilously low. "We're only covered for the next weeks, and very soon funding will run out," he added. Aid group capacity has been reduced by more than a third following budget cuts, and the banking system in the affected region barely functions, complicating payments.

The response is further hindered by local mistrust. Conspiracy theories that the outbreak is a hoax circulate, and some restrictions on traditional burial practices have been unpopular in affected communities.

The outbreak is centred on the east, where decades of conflict and the Rwanda-backed M23 rebel group have created an unstable environment. M23 has imposed new restrictions on movement between its areas and government-held zones, suspending shared taxis and boats for one month. Travelers have tested positive in an M23-controlled area, though the group declared its zones Ebola-free in late June.

Neighboring Uganda has recorded cases and declared itself free of the virus last month, but the UN coordinator warned that the risk of wider regional spread remains if the response is not stepped up.

Vaccine trials and gaps

The arrival of Ervebo provides a potential tool. Ervebo is licensed for the Zaire strain of Ebola, but the current outbreak is caused by the Bundibugyo strain, for which no vaccine is specifically approved. Early animal data suggests Ervebo may offer some cross-protection, and a Phase III trial with 20,000 doses will test this, with informed consent required.

Other candidates are in development, including a Bundibugyo-targeted vaccine from Moderna and a trial at the University of Oxford. The WHO has recommended a full-scale trial of Ervebo.

The vaccine doses, produced in Germany and developed by Merck, were welcomed by health minister Samuel Roger Kamba, who noted that Ervebo had been used previously on a large scale during the 2018-2020 outbreak.

The global response is coordinated with multiple UN agencies, WHO and Africa CDC, among others., supported by Gavi's funding of the vaccine stockpile. Neighboring Nigeria has activated its Emergency Operations Centre, highlighting concerns about potential spread.

Ebola has killed more than 15,000 people in Africa over the past 50 years. The current outbreak, declared three months ago, is already the country's deadliest, and the UN's Harneis warned that unless the pace of response improves, "this epidemic will become more deadly," spreading further.