Doctors Without Borders (MSF) has urged global health authorities to expand access to the ERVEBO Ebola vaccine as the Bundibugyo Ebola outbreak continues in the Democratic Republic of Congo, warning that delays could leave thousands of people vulnerable.

MSF called on the World Health Organization’s (WHO) Strategic Advisory Group of Experts on Immunization to remove restrictions that currently limit ERVEBO vaccination largely to research programmes. The organization says wider access could help protect frontline health workers, people exposed to confirmed cases and affected communities.

Although ERVEBO is not specifically designed to protect against the Bundibugyo virus responsible for the current outbreak, studies suggest it may offer some level of protection. Research in animals and studies of immune responses in vaccinated people have shown encouraging results.

No licensed vaccine currently exists specifically for the Bundibugyo virus, while candidate vaccines remain under development and may take months to yield results.

“Expanding access to ERVEBO offers the best immediate opportunity to help reduce severe illness and deaths while research on Bundibugyo-specific vaccines continues,” said Guyguy Manangama, an MSF epidemiologist and deputy director of operations.

Access to the vaccine remains limited, with most people only able to receive it through clinical trials or special-use arrangements.

MSF data indicate that between 2018 and 2024, more than 365,000 people were vaccinated with ERVEBO in North Kivu and Ituri provinces. MSF says observations from previous Ebola responses point to encouraging outcomes among vaccinated individuals.

The DR Congo government requested 500,000 doses in August through the WHO's International Coordinating Group on Vaccine Provision. However, only 70,000 doses were released.

MSF is urging vaccine manufacturer Merck and international health partners to increase supplies to meet growing needs.

The organization also stressed that vaccination must be accompanied by stronger surveillance, testing, contact tracing, quality medical care and community engagement to bring the outbreak under control.