Ebola & Marburg
The 2014-2016 Ebola outbreak in West Africa infected more than 28,000 people, took more than 11,000 lives and spurred funders and vaccine developers to urgent action. Years later, Ebola has returned and the world still lacks any treatments or licensed vaccines to protect against it or the closely related, but lesser known, Marburg virus.
We need an effective vaccine to protect more than 100 million people that are currently at risk of infection, as well as the global community to which an outbreak could spread. That’s why Sabin, in partnership with the Vaccine Research Center (VRC) at the National Institute of Allergy and Infectious Disease (NIAID), and powered by proprietary technology licensed from GSK, is preparing to address the enormous threat that Ebola and Marburg pose to the health of communities worldwide by advancing the development of several candidate vaccines against these diseases.
About the Vaccines
Currently, there are no licensed vaccines available to prevent Ebola and Marburg, which cause severe and often deadly infections. Under a new agreement with GSK beginning in 2019, Sabin has exclusively licensed the technology for three clinical-stage ChAd3-based vaccine candidates against Ebola Sudan, Ebola Zaire and Marburg viruses that were developed collaboratively by the U.S. National Institutes of Health and Okairos, which was acquired by GSK in 2013. The candidate vaccines were further developed by GSK, including the Phase II development for the Ebola Zaire vaccine. The Blavatnik Family Foundation and the David E.I. Pyott Foundation provided seed funding to launch Sabin’s ChAd3 Ebola program.
In addition to the agreement with GSK, Sabin is partnering with the VRC at NIAID through a Research Collaboration Agreement to further development of the three vaccines, based on GSK’s ChAd3 platform. The VRC is an established research center for Ebola and Marburg vaccines, and has been an important collaborator on the ChAd3 Ebola vaccine platform for more than a decade. By entering into these two agreements, Sabin will have an active role in advancing the development of vaccines to protect against Ebola Zaire, Ebola Sudan and Marburg.
The three vaccines have demonstrated strong safety profiles and immunogenicity results across 13 clinical trials. In total, the vaccines have been administered to more than 5,000 adults and 600 children, the majority of which were tested using the ChAd3 Ebola Zaire vaccine. In addition to numerous Phase I trials, the Ebola Zaire vaccine has been tested in three Phase II trials in Africa: two were conducted by GSK and one was conducted by the Partnership for Research on Ebola Virus in Liberia (PREVAIL), a clinical research partnership between NIAID and the Liberian Ministry of Health. The Ebola Sudan vaccine has been evaluated in three Phase I trials in Africa and the United States as a bivalent formulation with Ebola Zaire and will be evaluated in an upcoming Phase I study as monovalent formulation. A Phase I study of the Marburg vaccine is ongoing in the United States.
To read more information, please refer to our table of clinical trials.
About Ebola Zaire, Ebola Sudan and Marburg
Ebola Zaire, Ebola Sudan and Marburg are members of the Filoviridae family. Filoviruses are typically spread from wild animals to people, where transmission is continued through human-to-human contact. Though Marburg and Ebola are caused by different viruses, they manifest with clinically similar symptoms. Both can cause severe hemorrhagic fever in humans and nonhuman primates, with subsequent death in up to 90 percent of human cases.
Marburg was the first filovirus to be recognized in 1967 when a number of laboratory workers, including some in Marburg, Germany, developed hemorrhagic fever. Ebola was identified in 1976 when two simultaneous outbreaks occurred in northern Zaire (now the Democratic Republic of Congo) in a village near the Ebola River and southern Sudan. The outbreaks involved what eventually proved to be two different species of Ebola virus; both were named after the nations in which they were discovered.
The 2014-2016 outbreak in West Africa, the largest Ebola outbreak in history, was caused by Ebola Zaire, starting in Guinea and then crossing borders to Sierra Leone and Liberia. The outbreak spread to 10 countries and took the lives of more than 11,000 people. Ebola Zaire also caused the 2018-2019 outbreak in eastern DRC, which has claimed the lives of more than 1,700 people and was declared a Public Health Emergency of International Concern by the World Health Organization in July 2019, an action reserved for the most severe global health threats.
For more information on the ongoing 2018-2019 Ebola Zaire outbreak, refer to the World Health Organization’s Ebola Situation Report.
Why We Need a Vaccine
Marburg and Ebola viruses are transmitted to humans by infected animals, particularly fruit bats. Once a human is infected, the virus can spread to others through close personal contact or contact with bodily fluids. Currently, surveillance and isolation of infected people is the centerpiece of filovirus control. As there are no existing treatments for hemorrhagic fevers caused by filoviruses, primary prevention tools, such as an effective vaccine, are of the utmost importance.
An experimental Ebola Zaire vaccine, VSV-ZEBOV, is being used in the ongoing outbreak in DRC, in a “ring strategy.” The importance of having more than one vaccine during an outbreak is made clear when we consider what could happen to the vaccine supply should the situation worsen. As the current experimental vaccine takes nearly a year to produce, having a second option ready can ensure greater stability of the global vaccine supply for use in emergencies. Sabin’s new agreements to continue development of GSK’s ChAd3 Ebola and Marburg vaccines show promise to further close the gap in the prevention of these diseases. Sabin supports all potential interventions to prevent illness and death caused by Ebola and Marburg, including new treatments, diagnostics and preventive measures.