New Ebola Virus Vaccine Makes the Disease 'Preventable and Treatable'
By Dr. Brian Blodgett
Faculty Member, Homeland Security, American Military University
The World Health Organization (WHO) announced on Nov. 12, that it has prequalified Merck’s Ervebo as a vaccine for Ebola hemorrhagic fever.
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Prequalification means that the Ervebo vaccine meets the “WHO standard for quality, safety and efficacy.”
“This is a historic step towards ensuring the people who most need it are able to access this life-saving vaccine,” WHO Director-General Dr. Tedros Adhanom Ghebreyesus said in the announcement. “Five years ago, we had no vaccine and no therapeutics for Ebola. With a prequalified vaccine and experimental therapeutics, Ebola is now preventable and treatable.”
History of Ebola
Ebola was discovered in 1976 during two simultaneous outbreaks, one in Sudan and the other in Zaire, now known as the Democratic Republic of Congo, along the Ebola River, which gave the disease its name.
Since the initial outbreak, there have been another 28 recognized outbreaks in Africa. These outbreaks have resulted in over 34,000 cases and 15,000 deaths. The death rate for contacting the disease varies from 25 percent to 90 percent.
Ebola has four species: Bundibugyo (BDBV), Sudan (SUDB), Tai Forest (TAFV) and Zaire (EBOV) Ebola virus.
The deadliest is the Zaire Ebola virus, with a death rate approaching 45 percent. There have been 18 outbreaks of the Zaire Ebola virus in the Democratic Republic of the Congo, Gabon, Guinea, Liberia, Mali, Nigeria, Senegal, Sierra Leone, South Africa and Uganda.
The Zaire Ebola virus has infected over 33,000 persons and killed more than 14,000 individuals. The fatal 2014-2016 outbreak there infected 28,616 individuals and killed 11,310 victims.
The Sudan Ebola virus has been responsible for seven outbreaks in South Sudan and Uganda, infecting 778 individuals and killing 412. That is a death rate of 53 percent.
Bundibugyo Ebola virus is associated with only two outbreaks, one in the DRC in 2012 and another along the DRC and Uganda border in 2007, infecting 185 persons and killing 50, a death rate of 27 percent.
The 1994 Tai Forest outbreak occurred only in the Ivory Coast with just one confirmed case who survived.
Conditional Marketing of Ervebo
Two days before the WHO’s prequalification of the vaccine, the European Commission (EC) granted conditional marketing of Ervebo. Kenneth C. Frazier, Merck’s chairman and chief executive officer, commented: “After recognizing the need and urgency for an Ebola Zaire vaccine, many came together across sectors to answer the global call for outbreak preparedness.”
Approval of the EC allows Merck to initiate manufacturing with the vaccine becoming available in the third quarter of 2020. Over the past 18 months, the WHO has received more than 245,000 0.1-ml investigational dosages.
Merck reports that it has an additional 190,000 doses available which the pharmaceutical company is ready to ship to the DRC or to any outbreak area at the WHO’s request. Merck’s strategy is to produce an additional 650,000 investigational doses that will be available in the next six to 18 months.
Ervebo Strategy Places a Ring of Vaccinated Individuals around Known Cases to Prevent the Spread of the Virus
The WHO’s release of the vaccine is known as an “expanded access” or “compassionate use” research protocol. Under this protocol, the Ervebo doses are given to healthcare workers or those who have come into contact with infected patients. This strategy places a ring of vaccinated individuals around known cases to prevent the spread of the virus.
As of mid-November, over 253,000 individuals have received Merck’s vaccine, according to the French Comité Multisectoriel de là Roposte à la Maladie à Virus Ebola.
The expanded access protocol is often used for promising medicines that have yet to receive a license but are made available to individuals with an unmet medical need.
Chandy John, president of the American Society of Tropical Medicine and Hygiene, in discussing the spread of Ebola outbreaks, stated, “diseases now know no borders. What’s happening in the DRC matters to the U.S. for the health of our citizenry. And that’s a reason why we really need to dedicate U.S. dollars to this effort.”
Before the announcements by the EC and the WHO, Ervebo was tested on approximately 16,000 individuals throughout Africa, Europe, and the United States. The European Medicines Agency will continue its evaluation of Ervebo’s efficacy and safety data through continued review. The U.S. Food and Drug Administration (FDA) is reviewing a licensure application for the vaccine. A decision is expected by mid-March 2020.
Merck’s vaccine, made in the company’s plant in West Point, Pennsylvania, is from a live, replicating virus requiring only one shot. It is about 97% successful in protecting a person from becoming infected.
The vaccine is 100 percent effective for those who were exposed to the disease 10 days or more after being vaccinated. For patients who were exposed fewer than ten days before vaccination, the vaccine is about 84 percent effective. Even at half strength, at 0.05-ml – a tactic conducted in Guinea during the 2014-2016 deadly outbreak – the vaccine was successful.
Merck’s vaccine, developed by scientists at Canada’s National Microbiology Laboratory, received funding from the U.S. Department of Health and Human Services’ Biomedical Advanced Research and Development Authority.
In July, the Infectious Diseases Society of America (IDSA) urged Congress to provide a minimum of $172.5 million for USAID’s global health security efforts and $208.2 million for the CDC’s Division of Global Health Protection funding for the coming year.”
On November 8, just days before the WHO announced the availability of Ervebo, the U.S. Agency for International Development (USAID) announced that that it would provide an additional $56 million in humanitarian assistance to help end the ongoing outbreak of Ebola in the DRC. The $56 million would bring the total USAID funding to more than $266 million since August 2018.
While $56 million is far short of what IDSA thought Congress should appropriate, the United States remains the most significant contributor to the outbreak.
For example, the United States also has a Disaster-Assistance Response Team on the ground in the DRC composed of disaster and health experts from USAID and the CDC who work with humanitarian partners and the DRC government.
According to the USAID statement, “Stopping the spread of Ebola requires a concerted, unified effort from the entire international community including the United Nations and regional governments - all in close partnership with the Government of the DRC and local communities. The United States strongly encourages other donors to provide additional financial and technical support to help end the outbreak.”
About the Author
Dr. Brian Blodgett is an alumnus of American Military University who graduated in 2000 with a master of arts in military studies and a concentration in land warfare. He retired from the U.S. Army in 2006 as a Chief Warrant Officer after serving over 20 years, first as an infantryman and then as an intelligence analyst. He is a 2003 graduate of the Joint Military Intelligence College where he earned a master of science in strategic intelligence with a concentration in South Asia. He graduated from Northcentral University in 2008, earning a doctorate in philosophy in business administration with a specialization in homeland security.
Dr. Blodgett has been a part-time faculty member, a full-time faculty member and a program director. He is currently a full-time faculty member in the School of Security and Global Studies and teaches homeland security and security management courses.