Ebola Outbreak in the Democratic Republic of the Congo: A Race for a Vaccine
As the Ebola outbreak continues to ravage the Democratic Republic of the Congo (DRC), a groundbreaking effort is underway to develop a targeted vaccine for the Bundibugyo species of the virus. This strain, for which there is currently no approved vaccine, is behind the largest recorded outbreak in DRC’s history.
On July 30, the Coalition for Epidemic Preparedness Innovations (CEPI) announced it would provide up to $8.5 million in funding to Hilleman Laboratories, a Singapore-based vaccine manufacturer. This funding is aimed at advancing the development of a Bundibugyo Ebola vaccine and producing doses for human testing. Hilleman Laboratories, established by US biopharmaceutical giant MSD and the Wellcome Trust, is now at the forefront of this urgent vaccine development effort.
The Current Situation: An Unprecedented Outbreak
The Ebola outbreak in the DRC is growing at an alarming rate. As of September 7, the World Health Organization (WHO) reported over 6,757 confirmed cases and 3,267 deaths, leading to a staggering case-fatality rate of 48.3%. The outbreak now spans six provinces, with Ituri being the main area of concern. Further transmission is also notable in North Kivu and Haut-Uélé, alongside reports from South Kivu, Tshopo, and Bas-Uélé.
Described as the second-largest outbreak globally since the 2014-2016 West Africa epidemic, which claimed over 11,300 lives, this current crisis has escalated rapidly. WHO Director-General Tedros Adhanom Ghebreyesus expressed grave concerns, noting that the epidemic is “far from being under control.”
The Lack of an Approved Vaccine
Despite the severity of the outbreak, no licensed vaccine exists for the Bundibugyo strain. While MSD’s single-dose Ervebo vaccine is available, it primarily targets the Zaire species. Evidence on whether Ervebo can provide any cross-protection against Bundibugyo remains “limited and inconclusive.”
Mandeep Dhingra, CEPI’s director for research and development programs, highlighted that historical neglect and a lack of dedicated investment in Bundibugyo have left the world vulnerable. Previous Bundibugyo outbreaks have been rare, further fostering the misconception that it was not a priority for development.
Hilleman’s Vaccine Candidate
The innovative candidate developed by Hilleman Laboratories employs a recombinant vesicular stomatitis virus (rVSV) platform, which has a proven safety record. This same platform is utilized in the Ervebo vaccine. The candidate’s efficacy against Bundibugyo was demonstrated in animal studies, making it a promising option for combating the current outbreak.
Hilleman’s head of portfolio, Erlyani Hamid, confirmed that the initial doses are expected to be ready for clinical trials by the end of the year. Notably, the manufacturing process will benefit from upgrades funded through previous CEPI investments in Ervebo, streamlining production and allowing for easier storage conditions in areas with limited infrastructure.
Testing: What’s Happening Now?
In addition to Hilleman’s candidate, CEPI is also supporting several other Bundibugyo vaccine candidates currently in early human trials. One candidate being explored is a Moderna mRNA-1469 vaccine, with Phase 1 trials initiated in Canada. Another contender comes from the University of Oxford, using a ChAdOx1 BDBV platform.
WHO and the Africa CDC have pledged 70,000 doses of Ervebo to support health workers during this crisis, 20,000 of which will also be used in a trial assessing its efficacy against the Bundibugyo strain. There’s still a cautious tone regarding the potential for Ervebo’s efficacy against this specific strain.
The Challenge Ahead: From Panic to Preparedness
As the trials and funding continue to unfold, important challenges remain. The urgency of the current situation echoes a troubling cycle of “panic and neglect,” according to Dhingra. While immediate responses to outbreaks are crucial, the lack of sustained investment leads to a repeated struggle when a crisis strikes.
CEPI’s goal is to fast-track two Bundibugyo vaccine candidates to Emergency Use Authorization and WHO Prequalification, emphasizing the need for collaborative efforts to combat such health crises. It’s a race against time, as additional funding is sought to allow for readiness within a mere 100 days of identifying a pathogen.
In Summary
The DRC’s ongoing Ebola outbreak is a stark reminder of the urgency needed in vaccine development and global health preparedness. Organizations like CEPI and Hilleman Laboratories are working tirelessly to address this health emergency and lay the groundwork for future outbreaks. As clinical trials approach and funding accumulates, the world watches closely, hoping for a breakthrough in the battle against this deadly virus.