Ebola Virus: Symptoms, How It Spreads, Vaccines and Treatment — A Complete Guide

Disclaimer: This guide is general information only and is not medical advice. If you think you may have been exposed to Ebola, or you develop fever after travel to an outbreak area, contact local health authorities or seek emergency medical care immediately and tell them about your travel and contacts. Do not try to diagnose or treat yourself.

Read the companion guide: For the science in depth — virus structure, how it defeats the immune system, outbreak data and trial evidence — see our expert deep-dive: Ebola Virus Deep Dive: Virology, Pathogenesis, Outbreaks and the Evidence for Vaccines and Treatments

What is Ebola?

Ebola is a severe, often fatal viral illness that causes sudden fever and, in many patients, bleeding, organ failure and shock. It is not one single virus. “Ebola” is the family name for a group of closely related viruses in the genus Orthoebolavirus (previously called Ebolavirus), part of the filovirus family. Four of the six known species can cause disease in people:

• Ebola virus (EBOV) — species Orthoebolavirus zairense, often called Zaire ebolavirus. It has caused the largest number of outbreaks and the highest death rates.
• Sudan virus (SUDV) — species Orthoebolavirus sudanense.
• Bundibugyo virus (BDBV) — species Orthoebolavirus bundibugyoense.
• Taï Forest virus (TAFV) — species Orthoebolavirus taiense, which has caused human disease only rarely.
• Reston virus (RESTV) and Bombali virus (BOMV) are the other two species. Reston virus has not caused illness in people, and Bombali virus has been found in bats but has not been linked to human disease.

Doctors use slightly different names for the diseases these viruses cause: Ebola virus disease (EVD) for disease caused by Ebola virus itself, Bundibugyo virus disease (BVD) for Bundibugyo virus, and Sudan virus disease (SVD) for Sudan virus. In everyday language they are all usually just called “Ebola”, but the distinction matters, because the licensed vaccine and the approved treatments only work against Ebola virus (Zaire) — not against Bundibugyo or Sudan virus. That fact is central to the large outbreak happening in 2026, described below.

Ebola is a zoonotic disease, meaning it passes from animals to people. Fruit bats are believed to be the natural hosts, although this has not been definitively proven. People can become infected through contact with infected wildlife — for example while hunting, slaughtering or eating wild animals — and then the virus spreads from person to person.

How does Ebola spread — and how does it not spread?

Ebola spreads through direct contact with the blood or other body fluids of a person who is sick with Ebola or has died from it, or with objects contaminated with those fluids, such as bedding, clothing or needles. Fluids that can carry the virus include blood, vomit, diarrhoea, urine, sweat, saliva, tears, breast milk and semen, entering through broken skin or the mucous membranes of the eyes, nose or mouth. Family members, carers and health workers in close contact with patients are at highest risk, and unsafe burials — where mourners touch the body — have repeatedly amplified outbreaks.

Three points about timing matter enormously for controlling Ebola:

1. A person is not infectious before symptoms appear. The incubation period ranges from 2 to 21 days, typically 7 to 11 days. You cannot catch Ebola from someone exposed but not yet ill.
2. Infectiousness rises as the illness gets worse, because the amount of virus in blood and body fluids increases.
3. The virus can linger after recovery in places the immune system reaches poorly, such as the eyes, central nervous system and testes. Sexual transmission from male survivors has been documented. WHO recommends male survivors be offered semen testing from 3 months after illness onset, and abstain from sex or use condoms correctly and consistently until semen has twice tested negative, or for at least 12 months after symptoms began if testing is unavailable.

Ebola does not spread through the air like influenza or COVID-19, and it is not spread through water, through food grown or legally purchased outside outbreak areas, or by mosquitoes or other insects. Casual contact — being in the same room, shaking hands with someone who is not ill, or handling money — does not transmit Ebola. These facts are why outbreaks can be stopped by isolation, protective equipment, safe burials and contact tracing, even though the disease itself is so deadly.

Symptoms and what the illness looks like

Early Ebola is hard to recognise, because its first symptoms look like many other common illnesses — malaria, typhoid, dengue or flu. The illness usually begins suddenly with fever, intense weakness and fatigue, muscle pain, headache and a sore throat. After a few days, as the disease progresses, “wet” symptoms appear: nausea, vomiting, diarrhoea and abdominal pain, sometimes with a rash. In severe illness there may be bleeding — from the gums, nose, or in vomit or stool — but bleeding is not present in every patient; many patients never bleed visibly. The most dangerous phase involves falling blood pressure, confusion, kidney and liver failure and multi-organ failure. People who die usually do so between about day 6 and day 16 of illness, most often from dehydration and organ failure rather than from blood loss itself.

Doctors cannot diagnose Ebola from symptoms alone, especially early on. Confirmation requires laboratory testing, usually a blood test detecting the virus’s genetic material (RT-PCR). Anyone with fever who has recently been in an outbreak area, or had contact with a known case, should be tested promptly rather than waiting to see whether the illness worsens.

How deadly is Ebola? The WHO reports an average case fatality rate of about 50%, ranging from 25% to 90% across outbreaks, depending on the virus species, how early patients reach care, and the quality of supportive treatment. With early, intensive supportive care — intravenous fluids, electrolyte and blood-sugar correction, oxygen, blood-pressure support and treatment of other infections — many more patients survive. Even with the best care, Ebola remains very serious.

People who recover can face a long aftermath: joint and muscle pain, fatigue, headaches and eye inflammation (uveitis) that can threaten vision, plus anxiety, depression and post-traumatic stress after a disease that killed family members and neighbours. Survivors deserve follow-up care and respect rather than stigma: once recovered and cleared, a person is not a continuing danger to their community, except for the semen precautions described above.

A short history: from 1976 to today

Ebola was first recognised in 1976, when two simultaneous outbreaks of a mysterious haemorrhagic fever occurred in central Africa: one in Yambuku, in what is now the Democratic Republic of the Congo (DRC), near the Ebola River from which the disease takes its name, and one in Nzara, in what is now South Sudan. The Yambuku outbreak was caused by Ebola virus (Zaire) and killed about 88% of its patients. For the next three decades, outbreaks were sporadic and mostly small, in the DRC, Sudan, Gabon, Uganda and the Republic of Congo.

Everything changed in 2013–2016, when an outbreak that began in Guinea spread across West Africa and became the largest Ebola epidemic ever recorded: 28,610 confirmed, probable and suspected cases and 11,308 deaths in Guinea, Liberia and Sierra Leone, with a small number of cases exported elsewhere. The WHO declared it a Public Health Emergency of International Concern in August 2014 and ended that declaration in March 2016. It exposed how slowly the world had responded — but it also produced the first proven vaccine and treatments.

The second-largest outbreak followed in 2018–2020 in the DRC’s North Kivu and Ituri provinces, complicated by armed conflict and attacks on health workers. It caused 3,470 cases and 2,287 deaths — a case fatality rate of 66% — before it was declared over on 25 June 2020. It was during this outbreak that the landmark PALM trial proved that two monoclonal antibody treatments could cut mortality.

A smaller but very deadly outbreak struck Kasai province in the DRC in September 2025. Caused by Zaire ebolavirus, it produced 64 cases and 45 deaths (70.3% fatality) before being declared over on 1 December 2025, after 42 days without a new case.

The 2026 outbreak: why it is different

In May 2026 the DRC declared a new outbreak — its 17th — this time caused by Bundibugyo virus, a species for which there is no licensed vaccine and no approved treatment. The outbreak, centred on Ituri province in the east of the country, grew faster than any previous Ebola outbreak in the DRC and became the largest ever recorded there, regardless of virus species. The WHO declared it a Public Health Emergency of International Concern on 17 May 2026.

As of 6 October 2026, WHO reported 8,728 confirmed cases and 4,205 deaths in the DRC (48.2% fatality) across 64 health zones in seven provinces, with Ituri worst affected. By 20 October 2026, WHO reported 9,704 cases and 4,687 deaths (48.3%), with imported cases in Kenya (nine cases, one death) and Nigeria (one imported case in Abuja), and a smaller Uganda outbreak declared over in August 2026. DRC government figures on 27 October 2026 put confirmed cases above 10,000, with 4,887 deaths. Figures in an active outbreak change daily; read these as a late-October 2026 snapshot, not final totals.

The 2026 outbreak exposes a gap in medical science: the vaccine and drugs that transformed the response to Zaire ebolavirus do not automatically work against Bundibugyo virus, whose surface protein differs substantially from Zaire’s. On 23 October 2026, the first participants were vaccinated in Bunia, Ituri province, in a trial called Tumaini (“hope” in Swahili), testing whether Ervebo offers any cross-protection against Bundibugyo virus, and designed to add two Bundibugyo-specific candidates — an Oxford adenovirus-vector vaccine and a Moderna mRNA vaccine — as they become ready. Until results arrive, the response rests on the classic tools: rapid detection, isolation, contact tracing, safe burials and supportive care.

Vaccines and treatments: what actually exists

Ervebo (rVSV-ZEBOV) is the vaccine used in Ebola outbreak response. It is a live, weakened vesicular stomatitis virus engineered to carry Ebola virus’s surface glycoprotein, given as a single injection. A second vaccine regimen, Zabdeno and Mvabea (Janssen), is also approved for preventive use against Ebola virus disease, but it is a two-dose schedule and is not the product deployed for ring vaccination during outbreaks. It was tested in the “Ebola ça suffit” ring vaccination trial in Guinea in 2015, in which contacts of confirmed cases — and contacts of those contacts — were vaccinated immediately or after a 21-day delay. No cases occurred 10 days or more after randomisation among immediately vaccinated contacts, compared with 16 cases in the delayed group, giving an estimated vaccine efficacy of 100%, although with a wide confidence interval because the number of cases was small. The US Food and Drug Administration (FDA) approved Ervebo on 19 December 2019 for prevention of disease caused by Zaire ebolavirus in adults. Ring vaccination — vaccinating the ring of people around each new case — is now the standard outbreak strategy for Zaire ebolavirus, and it was used at scale in the 2025 Kasai outbreak, where more than 47,500 people were vaccinated.

Inmazeb (REGN-EB3) and Ebanga (ansuvimab, formerly mAb114) are the two approved treatments, both monoclonal antibodies that target Ebola virus’s surface glycoprotein and block it from entering cells. They were proven in the PALM randomised trial in the DRC, which enrolled 681 patients during the 2018–2019 outbreak. Death within 28 days occurred in 33.5% of patients who received Inmazeb and 35.1% of those who received Ebanga, compared with about 50% in the control group — a major improvement, but still a reminder that these drugs save lives rather than guaranteeing survival. The benefit was greatest when treatment started early and when the patient’s viral load was low. The FDA approved Inmazeb in October 2020 and Ebanga in December 2020, both for Zaire ebolavirus infection only. The WHO has made strong recommendations for treatment with either of these two monoclonal antibodies for Ebola virus disease.

Crucially, neither the vaccine nor either treatment is licensed for Bundibugyo or Sudan virus disease. Animal studies suggest Ervebo is not expected to protect against Bundibugyo or Sudan virus, and the antibody treatments have not had their efficacy established against other ebolavirus species. Supportive care — fluids, electrolytes, oxygen and treatment of complications — remains the mainstay for those species, and is life-saving in its own right.

Prevention and infection control

For people in or travelling to an outbreak area, prevention is practical and specific:

• Avoid contact with blood and body fluids of anyone who is sick, and do not touch the body of someone who has died from suspected Ebola. Safe and dignified burials by trained teams protect families and honour the dead.
• Avoid handling wild animals found sick or dead, and avoid bushmeat and raw or undercooked wild animal meat in outbreak areas.
• Health workers need full protective equipment — gloves, gown, mask and eye protection — and strict procedures for using and disposing of it. Many health-worker infections happened when infection control broke down.
• Wash hands with soap and water, or use alcohol-based hand rub, after any contact with a sick person or their environment.
• If you develop fever within 21 days of being in an outbreak area or having contact with a case, seek care immediately, mention the exposure, and avoid close contact with others until assessed.

Outside outbreak areas, the risk to the general public is extremely low, and no special precautions are needed beyond normal hygiene.

Myths, corrected

• “Ebola spreads through the air.” False. Ebola is not airborne. It requires direct contact with body fluids of a symptomatic patient or a contaminated object.
• “You can catch it from someone who was exposed but feels fine.” False. People are not infectious during the incubation period.
• “Everyone who gets Ebola dies.” False. The average fatality rate is about 50%, and with early treatment it is much lower. In the PALM trial, about two-thirds of patients who received antibody treatment survived.
• “There is a vaccine, so the 2026 outbreak should already be stopped.” Not for this virus. The licensed vaccine targets Zaire ebolavirus; the 2026 outbreak is Bundibugyo virus, and cross-protection is unproven — which is exactly what the Tumaini trial is testing.
• “Survivors are permanently dangerous.” False. Once recovered and cleared, survivors can safely return to normal life, with the single exception of the semen precautions described above.
• “Ebola is a bioweapon that escaped a lab.” There is no credible evidence for this; Ebola has caused natural outbreaks in Africa since 1976, consistent with a zoonotic virus.
• “Traditional remedies or antibiotics cure Ebola.” False. Antibiotics do not work against viruses, and no traditional remedy has been shown to treat Ebola.

The bottom line

Ebola remains one of the most dangerous infectious diseases known, but it is no longer the untreatable disease of 1976 or even 2014. For Zaire ebolavirus, there is now a licensed vaccine and two approved antibody treatments, and ring vaccination plus rapid case-finding can stop outbreaks. The unfinished business is stark in 2026: Bundibugyo and Sudan viruses still have no licensed vaccine or treatment, and defences against them still depend on the oldest tools — finding cases fast, isolating patients safely, tracing contacts, burying the dead safely, and giving excellent supportive care. Closing that gap is the most important Ebola research goal of the next decade.

Sources

1. World Health Organization. Ebola disease caused by Bundibugyo virus — Democratic Republic of the Congo. Disease Outbreak News, 2026-DON619 (figures as of 6 October 2026: 8,728 confirmed cases, 4,205 deaths, CFR 48.2%; previous Bundibugyo outbreaks CFR 30% in 2007 and 50% in 2012; no approved vaccines or specific treatments for Bundibugyo virus disease). https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON619
2. World Health Organization. Ebola virus disease — Democratic Republic of the Congo. Disease Outbreak News, 2025-DON589 (Kasai outbreak declared over 1 December 2025; 64 cases, 53 confirmed and 11 probable, 45 deaths, CFR 70.3%). https://www.who.int/emergencies/disease-outbreak-news/item/2025-DON589
3. World Health Organization. Ebola virus disease — Democratic Republic of the Congo. Disease Outbreak News, 2020-DON284 (2018–2020 outbreak: 3,470 cases, 3,317 confirmed and 153 probable, 2,287 deaths, CFR 66%, declared over 25 June 2020). https://www.who.int/emergencies/disease-outbreak-news/item/2020-DON284
4. World Health Organization. Ebola virus disease fact sheet and outbreak guidance (incubation 2–21 days, typically 7–11 days; average CFR about 50%, range 25–90%; transmission routes; semen-testing and 12-month safer-sex guidance; survivor sequelae). https://www.who.int/news-room/fact-sheets/detail/ebola-virus-disease
5. US Centers for Disease Control and Prevention. Ebola disease outbreak in the Democratic Republic of the Congo and Uganda. Health Alert Network HAN 00530, May 2026 (species list; Ervebo licensed for Orthoebolavirus zairense only and not expected to protect against Bundibugyo virus; no FDA-approved treatment for Bundibugyo virus disease; not spread through airborne transmission). https://www.cdc.gov/han/php/notices/han00530.html
6. US Centers for Disease Control and Prevention. Ebola outbreak caused by Sudan virus in Uganda. Health Alert Network HAN 00521 (Sudan virus: no licensed vaccine; no FDA-approved treatment; previous Sudan virus outbreaks about 50% mortality). https://www.cdc.gov/han/php/notices/han00521.html
7. Henao-Restrepo AM, Camacho A, Longini IM, et al. Efficacy and effectiveness of an rVSV-vectored vaccine expressing Ebola surface glycoprotein: interim results from the Guinea ring vaccination cluster-randomised trial. Lancet 2015;386:857–866. DOI: 10.1016/S0140-6736(15)61117-5.
8. Henao-Restrepo AM, Longini IM, Egger M, et al.; Ebola Ça Suffit Trial Consortium. Efficacy and effectiveness of an rVSV-vectored vaccine in preventing Ebola virus disease: final results from the Guinea ring vaccination, open-label, cluster-randomised trial (Ebola Ça Suffit!). Lancet 2017;389:505–518. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(16)32618-6/fulltext
9. Mulangu S, Dodd LE, Davey RT Jr, et al.; PALM Consortium Study Team. A randomized, controlled trial of Ebola virus disease therapeutics. New England Journal of Medicine 2019;381:2293–2303. (PALM trial: 681 patients enrolled; 28-day mortality 33.5% REGN-EB3, 35.1% mAb114, 49.7% ZMapp, 53.1% remdesivir.)
10. US Food and Drug Administration. FDA approves first treatment for Ebola virus (Inmazeb, October 2020) and FDA approves Ebanga (December 2020); FDA approval of Ervebo, 19 December 2019. Summarised in: National Vaccine Information Center, Ebola disease and vaccine pages. https://www.nvic.org/disease-vaccine/ebola?viewall=true
11. News Agency of Nigeria. WHO says Bundibugyo Ebola spreads to 3 countries, urges stronger regional response (WHO statement: as of 20 October 2026, DRC 9,704 confirmed cases and 4,687 deaths, CFR 48.3%; Kenya 9 cases including 1 death; Nigeria 1 imported case). https://nannews.ng/who-says-bundibugyo-ebola-spreads-to-3-countries-urges-stronger-regional-response/
12. Al Jazeera. WHO announces start of Ebola vaccine clinical trial in DR Congo, 24 October 2026 (Tumaini trial began 23 October 2026 in Bunia; Ervebo tested for cross-protection against Bundibugyo; Oxford adenovirus-vector and Moderna mRNA candidates to join). https://www.aljazeera.com/news/2026/10/24/who-announces-start-of-ebola-vaccine-clinical-trial-in-dr-congo
13. Al Jazeera. Ebola cases in DR Congo surpass 10,000 in fastest-growing outbreak, 27 October 2026 (DRC government data: 10,060 confirmed cases, 4,887 deaths). https://www.aljazeera.com/news/2026/10/27/ebola-cases-in-dr-congo-surpass-10000-in-fastest-growing-outbreak
14. United Nations News. ‘Burden and loss’ builds in DR Congo, as Kenya strengthens Ebola containment, October 2026 (9,765 cases, 4,727 deaths reported at briefing; Uganda outbreak declared over in August 2026). https://news.un.org/en/story/2026/10/1168655
15. Kuhn JH, et al. Renaming of genera Ebolavirus and Marburgvirus to Orthoebolavirus and Orthomarburgvirus, respectively, and introduction of binomial species names within family Filoviridae. Archives of Virology 2023 (taxonomy table: six species, including Orthoebolavirus zairense, bundibugyoense, sudanense, taiense, restonense, bombaliense).

Figures for the ongoing 2026 outbreak are snapshots as of late October 2026 and will change; check the WHO Disease Outbreak News page before republication.