in ,

Health Security Milestone: First FDA-Approved Ebola Vaccine

Ebola Virus - West Africa Outbreak
Credit: NIAID

The U.S. Food and Drug Administration announced today the approval of ERVEBO®, the first FDA-approved vaccine for the prevention of Ebola virus disease (EVD), caused by Zaire ebolavirus in individuals 18 years of age and older. The vaccine is a vital tool in combatting the ongoing Ebola outbreak in the Democratic Republic of the Congo (DRC), which is the second largest outbreak since the virus was discovered in 1976.

Support for ERVEBO® began about two decades ago when the Public Health Agency of Canada began developing the vaccine using a live virus vaccine platform based on the vesicular stomatitis virus, a virus that typically infects livestock rather than people.  The Public Health Agency of Canada licensed ERVEBO® to NewLink Genetics Corporation in 2011.  BioProtection Systems, a wholly owned subsidiary of NewLink, continued development of the vaccine with additional funding from the HHS as well as the Department of Defense (DoD).

The 2014 West Africa Ebola outbreak – the largest in history – galvanized public and private partners’ resolve to accelerate the development of the vaccine and other medical countermeasures that would be needed to respond to Ebola outbreaks.  Recognizing the threat to public health and national security, the U.S. Congress allocated supplemental funding to support the development of medical countermeasures and domestic public health preparedness measures.

In late 2014, with the Ebola outbreak at its peak, Merck licensed ERVEBO® from NewLink Genetics, and partners from the National Institutes of Health, the Centers for Disease Control and Prevention (CDC), the Biomedical Advanced Research and Development Authority (BARDA) within the HHS Office of the Assistant Secretary for Preparedness and Response, and DoD provided BioProtection Systems and Merck with funding and technical support for clinical trials, advanced development, and manufacturing of the vaccine.  When the West African Ebola outbreak finally ended in 2016, BARDA continued to support Merck’s late-stage development and manufacturing of ERVEBO®.

Merck and partners across the federal government remained committed to finishing the important work they started. In response to the current Ebola outbreak in the DRC, BARDA, CDC, and other partners in the U.S. government played an integral role in supporting the investigational use of ERVEBO®.  Throughout this time, the FDA provided critical scientific and technical input to U.S. government partners and Merck to facilitate the development of a safe and effective vaccine for EVD.

I am so proud that BARDA played an instrumental role in providing funding and technical support for this project. I am honored that our office had the opportunity to work with so many amazing people to produce a vaccine that is doing so much good. Our office supported activities from small scale manufacturing and phase 1 clinical development through the late-stage development of ERVEBO® that were required to support the licensure application. ERVEBO® is the 53rd BARDA-supported product to be approved or licensed by the FDA and it is the latest demonstration of the life-saving work that BARDA does each time it forms a new public-private partnership.

Robert Kadlec, MD, Assistant Secretary for Preparedness and Response, HHS

Today’s approval by the FDA, which follows last month’s European Union-wide conditional marketing approval by the European Medicines Agency and the World Health Organization’s prequalification of the vaccine, provides healthcare workers and civilians in affected areas with more confidence in the vaccine.

The vaccine is already playing an important role in the fight against Ebola in the DRC.  ERVEBO® has been given voluntarily to over 255,000 people, including first responders, healthcare workers, and burial providers, under an expanded access protocol. Contacts of suspected or confirmed Ebola patients have also been vaccinated to form a “ring of protection” and reduce further spread of the disease. The number of Ebola infections and deaths in the region continues to decline, thanks in part to the investigational vaccines and antivirals, as well as diagnostic tools developed with the support of the U.S. Department of Health and Human Services (HHS).

The first-ever FDA approval of a vaccine for the prevention of Ebola is a triumph of American global health leadership. From research and development to support for manufacturing, the U.S. government played an integral role in advancing the development of Merck’s vaccine. The newly approved vaccine, as well as investigational therapeutics and other tools supported by the U.S. government, is playing a huge role in saving lives during the current Ebola outbreak in the Democratic Republic of the Congo. When I led the U.S. delegation to Central Africa in September to learn more about the situation on the ground, we underscored that ending the Ebola outbreak is one of the top global health priorities for the Trump administration. We will continue strongly supporting the DRC government, other governments in the region, and the World Health Organization in their work until the Ebola outbreak is brought to an end, and we will continue working with governments around the world to prepare for and prevent such infectious disease outbreaks in the future.

HHS Secretary Alex Azar


The approval of ERVEBO® is supported by a study conducted in Guinea during the 2014-2016 outbreak in individuals 18 years of age and older. The study was a randomized cluster (ring) vaccination study in which 3,537 contacts and contacts of contacts of individuals with laboratory-confirmed EVD received either “immediate” or 21-day “delayed” vaccination with ERVEBO®. This noteworthy design was intended to capture a social network of individuals and locations that might include dwellings or workplaces where a patient spent time while symptomatic, or the households of individuals who had contact with the patient during that person’s illness or death. In a comparison of cases of EVD among 2,108 individuals in the “immediate” vaccination arm and 1,429 individuals in the “delayed” vaccination arm, ERVEBO® was determined to be 100% effective in preventing Ebola cases with symptom onset greater than 10 days after vaccination. No cases of EVD with symptom onset greater than 10 days after vaccination were observed in the “immediate” cluster group, compared with 10 cases of EVD in the 21-day “delayed” cluster group.

In additional studies, antibody responses to ERVEBO® were assessed in 477 individuals in Liberia, approximately 500 individuals in Sierra Leone and approximately 900 individuals in Canada, Spain and the U.S. The antibody responses among those in the study conducted in Canada, Spain and the U.S. were similar to those among individuals in the studies conducted in Liberia and Sierra Leone. 

The safety of ERVEBO® was assessed in approximately 15,000 individuals in Africa, Europe and North America. The most commonly reported side effects were pain, swelling and redness at the injection site, as well as headache, fever, joint and muscle aches and fatigue.

ERVEBO® is administered as a single-dose injection, and is a live, attenuated vaccine that has been genetically engineered to contain a protein from the Zaire ebolavirus.

The FDA granted this application Priority Review and a Tropical Disease Priority Review Voucher under a program intended to encourage development of new drugs and biologics for the prevention and treatment of certain tropical diseases. The FDA also granted Breakthrough Therapy designation for Ervebo to facilitate the development and scientific evaluation of the vaccine. Because of the public health importance of a vaccine to prevent EVD, the FDA worked closely with the company and completed its evaluation of the safety and effectiveness of ERVEBO® in less than six months.

The approval was granted to Merck & Co., Inc.

Sources: ASPR Blog, FDA press release

USAID Podcast: Strengthening Our Capabilities for Relief and Response

Fresh Approach to an Old Problem Yields Clues to Tularemia Virulence