WHO Projects Nine-Month Wait for Ebola Vaccine as Suspected Deaths Climb to 139

The World Health Organization has warned that it could take as long as nine months before a vaccine against the Bundibugyo strain of Ebola becomes available, even as the death toll from the outbreak in the Democratic Republic of the Congo and Uganda continues to climb.

In its latest update on May 21, 2026, the WHO reported 600 suspected cases and 139 suspected deaths. The numbers are expected to rise further because of delays in detection.

Of these, 51 cases have been laboratory-confirmed in eastern DRC, mainly in Ituri Province and parts of North Kivu. Two confirmed cases have been recorded in Uganda’s capital, Kampala, both involving individuals who had travelled from the DRC; one of them has died.

The outbreak, caused by the relatively rare Bundibugyo species of Ebola virus, was declared a Public Health Emergency of International Concern by WHO Director-General Dr Tedros Adhanom Ghebreyesus on May 17. However, it does not meet the criteria for a pandemic emergency as the WHO assesses the risk as high at national and regional levels but low globally.

Two candidate vaccines against Bundibugyo are in development, but neither has yet entered clinical trials. WHO adviser Dr Vasee Moorthy said one promising candidate, similar in platform to the existing Zaire Ebola vaccine, is likely to take six to nine months before it is ready. A second candidate, based on the same technology platform as the AstraZeneca Covid-19 vaccine, is already being manufactured, but lacks animal trial data.

Doses for possible clinical trials could become available in two to three months, though significant uncertainty remains.There are currently no approved vaccines or specific therapeutics for the Bundibugyo strain, unlike the more common Zaire strain. Early supportive care remains the main treatment option.

The first known case was a nurse who died in Bunia, the capital of Ituri Province, on April 24. Her body was later repatriated to Mongwalu, one of the gold-mining towns at the centre of the outbreak.

Health facilities in the affected areas are under severe strain. Médecins Sans Frontières (MSF) emergency programme manager Trish Newport said some centres are reporting they are “full of suspect cases” with no space left. Healthcare workers have died, raising concerns about infection control and shortages of personal protective equipment. The UK government has announced up to £20 million in emergency funding to support frontline health workers, improved infection prevention, and disease surveillance.

Eastern DRC’s long-running conflict, high population mobility, and the fact that early Ebola symptoms closely resemble those of common illnesses such as malaria and typhoid have complicated the response. Community habits are changing, however. Residents in Bunia have begun reducing handshakes and other close-contact greetings as awareness grows.

The Bundibugyo strain has caused only two previous outbreaks – in Uganda in 2007 and DRC in 2012 – with a case fatality rate of around one-third. This is lower than some other Ebola species but still poses a serious threat in a region already facing insecurity and weak health infrastructure.

Investigations are continuing to establish how long the virus had been circulating undetected before the first confirmed cases.