Three Ebola Vaccines Fast-Tracked as Outbreak Spreads in East Africa
Shola Lawal
At least three Ebola vaccines are being urgently researched and funded as a rare Bundibugyo strain outbreak spreads across East Africa, with hundreds infected and no approved vaccine for this strain. The outbreak began in eastern DRC's conflict-hit Ituri province and has spread to Uganda. While vaccines exist for the more common Zaire strain, none have been approved for Bundibugyo, prompting accelerated trials.
East Africa is facing a rapidly spreading Ebola outbreak, prompting governments to scramble to contain the virus as hundreds of confirmed cases pile up.
The Africa Centres for Disease Control and Prevention (Africa CDC) first declared the outbreak on May 15 in Ituri province, eastern Democratic Republic of Congo (DRC), a conflict-ridden region. The disease has since crossed into neighboring Uganda, which shares a border with eastern DRC.
The World Health Organization (WHO) declared a public health emergency two days after the outbreak was announced, when hundreds were already infected. Last week, WHO warned that ongoing conflict in the DRC is hampering efforts to curb Ebola's spread.
While three vaccines are under study and slated for accelerated trials, none have yet been approved for this virus strain.
The outbreak began in DRC's eastern Ituri province, where clashes between armed groups and Congolese forces persist and health resources are already stretched thin. As of June 2, WHO recorded at least 321 confirmed infections in the DRC, along with 116 suspected cases, 48 deaths, and six recoveries.
In Uganda, WHO confirmed nine infections and at least one death as of Tuesday. That same day, the Ugandan government reported six new cases, raising the total to 15. Infections have been confirmed in the capital, Kampala, hundreds of kilometers from the DRC border.
Experts warn this outbreak could rival some of the most severe Ebola epidemics. The worst outbreak hit West Africa in 2014, infecting some 29,000 people with the Zaire strain and killing over 11,000 over two years. Combined with a shortage of vaccines and protective gear for health workers, the outlook for this outbreak is grim.
“Responding to any Ebola outbreak is challenging, and here it's in a context where there is already a massive humanitarian need,” said Trish Newport, deputy Ebola program manager for Doctors Without Borders (MSF) in the DRC.
Newport noted that budget cuts—including large-scale U.S. foreign aid reductions under President Donald Trump last year—have forced many health and relief organizations to pull out of Ituri, undermining the response.
The virus causing the current outbreak is Bundibugyo, a rare Ebola species first identified in Uganda in 2007 and later in the DRC in 2012. It is not the Zaire strain behind recent outbreaks, such as the 2014-2016 West Africa epidemic and the 2018-2020 DRC outbreak.
There are two vaccines for the Zaire strain—the deadliest, with a 50-70% fatality rate. They are Merck's Ervebo and Johnson & Johnson's two-dose Zabdeno and Mvabea. However, because Bundibugyo outbreaks (30-50% fatality) are rarer, there has been insufficient opportunity for vaccine research and trials.
“This is only the third time in history that there has been an outbreak with the Bundibugyo virus, so it doesn't draw the attention of pharmaceutical companies,” said MSF's Newport. “For them, it's not considered a priority.”
The Coalition for Epidemic Preparedness Innovations (CEPI), a public-private partnership funding this effort, said Monday that three vaccines are being evaluated for emergency trials. CEPI did not disclose when those trials might begin. However, initial research, evaluation, and testing can take years, while manufacturing may take months.
The three known vaccines are:
International AIDS Vaccine Initiative (IAVI) will receive $3.2 million to develop a vaccine using a harmless, weakened animal virus to deliver genetic instructions the body can decode.
Moderna will receive $50 million for trials using flexible mRNA technology, which allowed the company to rapidly produce vaccines during the COVID-19 pandemic.
University of Oxford will receive $8.6 million to develop a vaccine based on the same technology used for the Oxford/AstraZeneca COVID-19 shot. This method also uses a modified version of a chimpanzee cold virus to deliver the vaccine.
These vaccines will be manufactured by the Serum Institute of India.
However, there are concerns that people in affected areas, especially in the DRC, may be reluctant to accept vaccines even if available. Stigma and misinformation about Ebola and other diseases have long fueled vaccine hesitance in Congolese communities, sometimes sparking anger toward health workers.
Last week, violent protests rocked the town of Rwampara when angry youths demanding the bodies of deceased relatives for burial broke into a hospital and set fire to Ebola treatment tents and other health infrastructure. Still, experts say that despite the tensions, vaccines for the Bundibugyo virus, once available, will be crucial as they could significantly limit the outbreak's spread.
