Vaccines for a suite of lethal viruses – including the one behind the unfolding Ebola emergency – must be developed urgently, warn epidemiologists. They also caution that while the global pandemic potential of Ebola is minimal, the outbreak highlights the perils of funding cuts at the World Health Organization.

The US began withdrawing funding for the World Health Organization (WHO) in early 2025, which forced the organisation to slash its budgets for 2026/27. “The key here is that the WHO is now greatly underfunded and they’ve had to shed huge numbers of staff,” says at Adelaide University, Australia. “So I think that the message here is that America leaving the WHO has been disastrous, basically.”

in the Democratic Republic of the Congo (DRC) on 5 May. Cases have now also been reported in Uganda.

“The first currently known suspected case, a health worker, reported onset of symptoms including fever, haemorrhaging, vomiting and intense malaise on 24 April 2026,” according to the WHO. On 17 May, the organisation declared the crisis in the DRC and Uganda to be a public health emergency of international concern.

The US Centres for Disease Control and Prevention suspected cases of an Ebola strain called Bundibugyo, and 88 related deaths. The Bundibugyo strain has a mortality rate of between 20 and 50 per cent among known cases.

There are two licensed vaccines for Zaire ebolavirus, the strain that has caused the biggest outbreaks and has the highest case-mortality rate, at up to 90 per cent. No vaccines exist for Bundibugyo virus, though some have been undertaken in non-human primates. This means the WHO has been emphasising the importance of containment for halting the spread of the Bundibugyo virus.

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In January this year, , in collaboration with partners including Moderna, it was working on vaccine candidates that would target multiple filoviruses – a group of RNA viruses that can cause lethal haemorrhagic fevers – including Bundibugyo and other strains of Ebola, as well as Marburg viruses.

Now, Esterman says that in light of the new crisis, this work must be brought forward. “The current outbreak makes a compelling case for accelerating this work,” he says. “We’ve known Bundibugyo exists for nearly two decades, yet we still lack vaccine options. This outbreak shows the real cost of that gap.”

He says a multivalent vaccine development programme addressing all known filovirus species “shouldn’t wait for bureaucratic and regulatory slowness”. “Faster doesn’t mean cutting safety corners, but there’s room to undertake vaccine trial phases in parallel, increase funding and use adaptive designs,” adds Esterman.

at the University of New South Wales, Sydney, Australia, says that until now, Ebola vaccine research has been focused on the Zaire strain. But she says that mRNA technology means that vaccines for filoviruses like Bundibugyo can be developed “very quickly”.

One reason these filoviruses don’t have vaccines yet is because of the economics of drug development, says MacIntyre. “Ebola is a disease that affects predominantly low-income countries, and 90 per cent of drug development happens around diseases that affect people in high-income countries,” she says.

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MacIntyre adds that because Ebola doesn’t spread as easily as infections such as SARS-Co-V2, the outbreak is unlikely to spread to other continents as a pandemic. But isolated “low-risk, high-consequence” cases in wealthier nations are possible as travellers to the impacted areas fly elsewhere in the world, she says.

Emergency departments everywhere should ask any patients presenting with a fever whether they have travelled in Central Africa so adequate quarantine measures can be put in place, says MacIntyre. “Any emerging infectious disease, whether it’s MERS [Middle Eastern respiratory syndrome] coronavirus, Ebola, hantavirus or even something like measles, spreads through travel,” she says.

“If they don’t identify that you’ve travelled somewhere where a serious epidemic is happening, you could be sent out to the waiting room to sit there for 3 hours until you’re seen and infect other people.”

For the first time, officials in Uganda have introduced a 21-day lockdown in two of the country’s districts in a bid to stem rising Ebola cases.

Since 15 October, bars, entertainment venues, markets and places of worship in Mubende and Kassanda in central Uganda have been forced to shut. Only goods lorries will be allowed in and out of the districts over the three weeks. A curfew has also been put in place, forcing people to remain at home between 7pm and 6am.

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According to Emmanuel Mutoo at the it is unclear why a lockdown has been introduced when previous Ebola outbreaks in Uganda had a higher number of cases.

As of 19 October,  and 24 confirmed deaths throughout the country.

Although the ministry doesn’t specify which districts these cases and deaths arose in, a World Health Organization (WHO) report details 58 confirmed cases throughout Uganda as of 14 October, of which 50 were in Mubende and three in Kassanda. Mubende has had 38 confirmed or probable deaths, compared with one fatality in Kassanda, according to the report.

Amid the ongoing outbreak, the first Ebola death was confirmed on 19 September – a . The virus later killed six members of his family.

On 12 October, Uganda’s health minister, , confirmed that , Kampala, more than 90 miles from the centre of Mubende.

The outbreak is being driven by the Sudan variant of the Ebola virus. Like all Ebola variants, this mainly spreads via contact with an infected person’s bodily fluids, such as blood or vomit. Symptoms can include fever, abdominal pain and unexplained bleeding.

In previous outbreaks, the estimated case-fatality rate of the Sudan variant has varied from 41 per cent to 100 per cent, according to the WHO.

No vaccine has been approved for this variant specifically. Two vaccines are available for the Zaire variant, manufactured by Merck and Johnson & Johnson. On 26 September, , based on available evidence. The two-dose Johnson & Johnson vaccine regimen hasn’t been tested against the Sudan variant in humans and the second dose must be administered at least 56 days after the first dose, making it unsuitable for an emergency response, .

Personal protective equipment for healthcare workers is in short supply, says Mutoo. by the virus so far.

Healthcare workers also fear cases may rise in more rural parts of Uganda where there is less advanced access to medical treatment and it may be difficult to trace contacts, says Mutoo.

Uganda’s government is attempting to stem the outbreak by tracing and isolating the contacts of people who test positive. “Some of the challenges with contact tracing is that some people don’t have phones and so you have to walk to find them, which takes time,” says Mutoo. “By the time you get there, they may have moved from this place or another.”

Among contact tracers who have phones, health officials may not have given them enough money or mobile data to call or message potential cases, while others haven’t been given enough money for fuel, according to Mutoo. “With the economy right now, everything is expensive,” he says.

Outside of lockdown, many Ugandans work in market stalls and therefore lose money if they stay at home for the 21-day isolation period. “Telling someone to keep home when they can’t have something to eat is difficult,” says Mutoo.

While there are no approved vaccines for the Sudan variant, at least six vaccine candidates are in development, . One, developed by the same team behind the University of Oxford/AstraZeneca covid-19 vaccine, and will be deployed in Uganda in two weeks, .

, called MBP134, to help protect healthcare workers.

If there are no more deaths by the end of October, Mutoo will consider the outbreak under control. “I don’t want to lose faith,” he says.

On 14 February, the government of Guinea an Ebola outbreak after three people tested positive in Gouécké, a rural community. As of 2 March, 17 cases have been reported (13 confirmed and four probable) with seven deaths.

Guinea’s ministry of health and public hygiene has acted swiftly to set up three nearby vaccination sites, each with the capacity to inoculate 100 people daily – the first time an Ebola vaccine has been deployed in the country. As of 28 February, 1002 people had been vaccinated in Guinea, including 66 high-risk people who had been in contact with suspect cases.

“In the coming days, we will be able to vaccinate more people in order to contain this pandemic properly,” says Bachir Kanté, an official at the health ministry.

The Ebola virus is more deadly than the coronavirus, but spreads less quickly, providing West Africa with a grace period to control its spread, says Christian Happi at the African Center of Excellence for Genomics of Infectious Diseases in Ede, Nigeria.

“Our collective, quick action is crucial to averting an uncontrolled spread of Ebola,” says Matshidiso Moeti, the World Health Organization’s regional director for Africa.

Guinea’s last Ebola outbreak, which started in 2014, spread to Liberia and Sierra Leone. By the time it was finally brought under control, it had become the deadliest Ebola outbreak since the virus was first detected in 1976, with about 28,000 cases and 11,000 deaths.

The latest Ebola outbreak in Guinea is close to its borders with Liberia, Sierra Leone and Ivory Coast, so neighbouring countries are increasing their preparedness to contain the spread of the outbreak.

The Guinean outbreak is happening at the same time as . The DRC held about 8000 vaccine doses for emergency use after its last outbreak in 2020, and has already begun to deploy them.

Both nations are tackling their outbreaks on top of dealing with the ongoing coronavirus pandemic. Guinea has seen 16,005 confirmed covid-19 cases and 89 deaths, and the DRC has had 25,144 cases and 700 deaths.

Vaccination strategies against the two viruses differ, says John Nkengasong at the Africa Centres for Disease Control and Prevention. “For covid-19, you want to vaccinate as many people as possible to be able to achieve herd immunity, but for Ebola, you want to identify close contacts and individuals at most risk for ring vaccination,” he says.

Kanté says that Guinea’s covid-19 response has benefited from capabilities for contact tracing and testing that were acquired during its 2014-2016 Ebola outbreak, while the ongoing Ebola vaccination efforts are helping the country test efforts that could be deployed for covid-19 vaccinations, which have yet to begin.

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The Democratic Republic of the Congo (DRC) has declared an official end to its 11th Ebola outbreak nearly six months after it began, marking the first time in years the vast central African country has been free of the deadly haemorrhagic fever.

Eteni Longondo, the DRC’s minister of health, and the World Health Organization (WHO) made the announcement on 18 November after no new cases of the viral disease had been recorded in the country’s western Équateur province for 42 days, or the time of two maximum incubation periods for Ebola. In this outbreak, there were 55 deaths and 75 people who had recovered out of 119 confirmed and 11 probable cases.

The outbreak, which was announced on 1 June, surfaced shortly before the DRC called an end to a separate Ebola epidemic – hundreds of miles away in the east of the country – that killed 2280 people over nearly two years. Genetic sequencing showed that the two virus strains were unrelated.

The latest outbreak stretched vast distances across dense rainforests and remote waterways as well as busy urban areas. It was halted thanks to “cold chain” vaccine storage technology and community-based health workers who vaccinated 40,000 people deemed at high risk of contracting the disease, according to experts.

“The geography was very difficult in terms of accessibility,” says Ngoy Nsenga at the WHO. “It required serious logistics, and so this ultracold-chain technology was very important.”

Known as the Arktek and originally developed by the Global Good Fund, a US-based social enterprise, the cylinder-shaped “super thermos” devices can store 500 vaccine doses at -80°C for up to a week with no external power source. This meets the cold temperature requirements of the Merck Ebola vaccine, as well as those of Pfizer and BioNTech’s new covid-19 vaccine, which bodes well for vaccination in lower-income countries with less-developed infrastructure.

“But there were so many factors in the management of the outbreak,” says Nsenga. “The DRC is gaining experience in stopping epidemics and the WHO has learned to react as quickly as we can.”

Bob Ghosn at the International Federation of Red Cross and Red Crescent Societies (IFRC) says working with local people was crucial to the success.

“Community engagement is key to stopping any outbreak,” says Ghosn, who helped deploy a team of 1000 IFRC community workers in Équateur. “We’ve got much better at it. Top-down messaging doesn’t work on its own – covid-19 has proved that.”

However, experts warn that the risk remains of another Ebola outbreak in the DRC – adding to the 11 since 1976. The disease, which can cause uncontrollable internal bleeding, is zoonotic and is believed to derive from a species of bat.

Natalie Roberts at Doctors Without Borders in France says future efforts are likely to improve with the use of monoclonal antibodies – laboratory-made molecules that can enhance the immune system.

“Due to the remote nature of this outbreak and other constraints, we weren’t able to use them as much as we wanted,” she says. “But they are very effective in the early stages of the disease.”

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