The medical charity says the available ERVEBO vaccine could help protect people at risk while vaccines specifically targeting the Bundibugyo strain remain under development.
By Bunmi Yekini
Médecins Sans Frontières (MSF) has called for wider access to the ERVEBO Ebola vaccine in the Democratic Republic of Congo (DRC), saying it could help protect people at risk as the Bundibugyo virus outbreak continues.
The medical humanitarian organisation said although ERVEBO was not specifically developed against the Bundibugyo strain, emerging scientific evidence and observations from previous Ebola responses suggest it could offer some protection.
No vaccine has yet been licensed specifically for the Bundibugyo ebolavirus, while candidate vaccines remain under development, with results not expected for several months.
MSF warned that waiting for a disease-specific vaccine could leave healthcare workers, frontline responders, contacts of confirmed cases and affected communities exposed to the potentially deadly disease.
“For MSF, the absence of a Bundibugyo-specific vaccine should not prevent the use of the only vaccine currently available,” said Guyguy Manangama, an epidemiologist and deputy director of operations at the organisation.
He urged authorities to remove restrictions tying ERVEBO vaccination to research protocols, arguing that available doses should be deployed quickly to protect those most at risk.
ERVEBO is licensed for use in people aged one year and above and has an established safety profile, with previous operational use during Ebola responses in the DRC.
However, access to the vaccine remains limited. MSF said frontline workers could receive it through research protocols or compassionate-use arrangements, while contacts of confirmed cases generally have access only through ongoing clinical trials.
The organisation said the strict requirements for enrolment in these trials meant that only a small proportion of potentially eligible people could be vaccinated.
Evidence from animal studies and immunological research suggests that the immune response triggered by ERVEBO may also recognise the Bundibugyo virus, although its effectiveness against the strain has not been established.
Etienne Gignoux, an epidemiologist and director of the Department of Epidemiology at MSF’s research centre, Epicentre, said observations by teams involved in previous Ebola responses in the DRC had also provided encouraging indications.
These included fewer confirmed cases and indications of lower mortality among people who had received vaccination before becoming infected during the 17th Ebola outbreak, he said.
Gignoux acknowledged that public health decisions during outbreaks often had to be made before all scientific evidence was available.
“Public health authorities must balance the need for research with the urgent need to save lives,” he said.
MSF said expanding vaccination would also require a substantial increase in available doses.
The DRC Ministry of Health has already widened access through compassionate-use arrangements, but the organisation said additional resources and the release of more doses from existing stockpiles were necessary.
In August, the DRC government, with support from Africa Centres for Disease Control and Prevention (Africa CDC), requested 500,000 doses of ERVEBO from the World Health Organization’s International Coordinating Group (ICG) on Vaccine Provision.
Only 70,000 doses were released, according to MSF.
The organisation warned that the shortfall could become more concerning as the outbreak spreads and cases are reported beyond the DRC, potentially increasing vaccination needs in neighbouring and other at-risk countries.
It called on vaccine manufacturer Merck, global health authorities and partners to ensure that allocations reflect the scale of public health needs.
MSF also said the World Health Organization’s Strategic Advisory Group of Experts on Immunization (SAGE) was expected to consider the issue at its next meeting on November 17.
The organisation stressed, however, that vaccination alone would not contain the outbreak.
It called for stronger surveillance, rapid case detection, laboratory testing, contact tracing, quality clinical care, infection prevention and control, safe and dignified burials, community engagement and support for frontline health workers.
The outbreak, MSF said, also highlights wider weaknesses in global epidemic preparedness, including the need for sustained investment in vaccine research, manufacturing capacity and technologies that can deliver affordable vaccines quickly when new infectious diseases emerge.