The Ebola Virus

What It Covers

Ebola, a filovirus first identified in 1976 during simultaneous outbreaks in Sudan and Zaire, carries a 25–90% fatality rate, spreads through bodily fluids, and now has a WHO-approved vaccine targeting its deadliest strain.

Key Questions Answered

• •Transmission mechanics: Ebola spreads exclusively through direct contact with blood, bodily fluids, or contaminated objects like needles and bedding — not through air. This fluid-only transmission explains why basic PPE (masks, gloves, gowns) successfully halted the 1995 Kikwit outbreak of 315 cases.
• •Fatality rate context: WHO reports an average Ebola case fatality rate of 50%, ranging from 25–90% depending on strain and care quality. This places it above smallpox but below rabies, and far deadlier per case than influenza or measles, though far less contagious.
• •Airborne mutation risk: For Ebola to become airborne, it would need to simultaneously develop replication in the upper respiratory tract, high shedding from lungs, aerosol survival, and inhalation infectivity — changes so fundamental they would constitute an entirely different virus biologically.
• •Vaccine efficacy and limits: The Merck-licensed vaccine Ervebo, developed from Canada's Public Health Agency research, achieved zero infections among immediately vaccinated contacts in Guinea's 2015 ring vaccination trial across 16,000 participants. It protects only against Zaire strain, leaving four other variants unaddressed.