Ebola Disease and Vaccine Quick Facts

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Quick Facts

Ebola (Ebola Hemorrhagic Fever)

Ebola is a serious contagious disease with a high mortality rate. The incubation period from initial exposure to onset of acute disease symptoms is between 2 and 21 days with the average being 8 to 10 days. Symptoms start with a fever, headache, muscle and stomach pain, diarrhea, vomiting, and skin bruising and may also include a skin rash, red eyes, and hiccups. Additional symptoms may include shortness of breath, chest pain, confusion, seizures, and bleeding. White blood cell and platelet counts decrease and both internal and external bleeding can occur. Fatal cases usually present with more severe symptoms early in the course of the illness, and death generally occurs from sepsis or multiorgan failure between day 6 and 16.
The Ebola virus is transmitted through direct contact with infected blood or body fluids, or by coming into contact with objects infected by the virus. It can also be spread through exposure to infected primates (apes, monkey, etc.) or fruit bats. A person with Ebola virus is only contagious to others after they begin to show signs of illness.
Treatment of Ebola virus disease includes intravenous fluid administration, oxygen supplementation, blood pressure monitoring and stabilization, and treatment of any secondary infections. There are two treatments currently approved for use by the U.S. Food and Drug Administration (FDA) to treat Ebola virus disease caused by species Zaire ebolavirus in children and adults. The first approved treatment, Inmazeb, is a combination of three monoclonal antibodies and the second treatment, Ebanga, is a human monoclonal antibody.
Persons who survive Ebola virus disease develop long-term immunity; however, health problems frequently persist upon recovery. Common symptoms include fatigue, headaches, weight gain, vision disturbances, joint and muscle pain, loss of appetite, and stomach pain. Additional long-term health issues can also include dry mouth, neck swelling, tightness of the chest, hearing problems, memory problems, tingling and pain in the hands and feet, changes in menstruation, impotence, inflammation of the testicles, decreased sex drive, sleep disturbances, inflammation of the tissues surrounding the heart, anxiety, depression, and post-traumatic stress disorder.
Ebola virus disease was initially discovered in 1976 after two separate outbreaks of hemorrhagic fever occurred in different areas of Central Africa. The first occurred in the Democratic Republic of Congo, near the Ebola River, and the second occurred approximately 500 miles away, in South Sudan.

Ebola Vaccines

On December 19, 2019, the FDA approved Merck’s ERVEBO Ebola vaccine, a genetically modified live Ebola virus vaccine for use in persons 18 years of age and older. The vaccine targets the species Zaire ebolavirus. The CDC’s Advisory Committee on Immunization Practices (ACIP) recommends that ERVEBO be given to all persons responding to an outbreak of Ebola virus disease, healthcare workers treating patients at federally-designated Ebola treatment centers in the U.S., biosafety-level 4 laboratory personnel, healthcare personnel at specialized pathogen care centers, and to support and laboratory staff at Laboratory Response Network facilities.
The ERVEBO package insert reports that the vaccine has the potential to infect others with vaccine-strain Ebolavirus due to virus shedding.
Adverse events reported during clinical trials included: injection site pain, swelling, and redness; headache; fever; nausea; fatigue; muscle pain; joint pain, swelling, stiffness, warmth, and redness; abnormal sweating; rash; vesicular lesions; arthralgia; arthritis; and anaphylaxis.
The vaccine package insert also noted that white blood cell counts were evaluated in nearly 700 individuals who received ERVEBO. Decreases in neutrophils were noted in at least 43 percent of vaccine recipients, and 85 percent experienced a decrease in lymphocytes. Neutrophils, a type of white blood cell, are vital to the immune system as they attack and destroy bacteria that invade the body. Low neutrophil counts can put an individual at a higher risk of serious infection. Leukocytes, another type of white blood cell, are also critical to the immune system and protect the body against infection.Additionally, persons who receive ERVEBO could have an immune response that might prevent laboratory tests from differentiating between wild-type and vaccine-strain Ebola infection.
Using the MedAlerts search engine, from FDA approval in December 2019 through March 29, 2024, there have been 52 reports of Ebola vaccine reactions, hospitalizations, injuries, and deaths following Ebola vaccination made to the federal Vaccine Adverse Events Reporting System (VAERS), including 3 hospitalizations, 3 related disabilities, and 1 related death.

IMPORTANT NOTE: NVIC encourages you to become fully informed about Ebola and the Ebola vaccine by reading all sections in the Table of Contents, which contain many links and resources such as the manufacturer product information inserts, and to speak with one or more trusted health care professionals before making a vaccination decision for yourself or your child. This information is for educational purposes only and is not intended as medical advice.

Centers for Disease Control (CDC)

Food and Drug Administration (FDA)

ERVEBO (Ebola Zaire Vaccine, Live) – Merck Sharp & Dohme Corp. - Package Insert and Licensing Information

Ebola Preparedness and Response Updates from FDA

National Institutes of Health (NIH) and Affiliates

World Health Organization (WHO)

Ebola Virus Disease - WHO Fact Sheet, Feb 23, 2021