What is a Virus? | Breakthrough

Virus is actually just genetic material encased in an envelope, and it actually needs a host like me or you in order for it to infect and continue to produce more copies of itself. So what happens is a virus infects me, let's say, and my immune system starts trying to control that virus. Well, the virus evolves and mutates and changes its genetic material over time to try to outrun my immune system.

So, it's a constant battle between the host and the virus, and basically, they're evolving together, they're co-evolving. Ebola is a filovirus, part of a rare family of viruses transmitted by direct contact with bodily fluids, often blood. By contrast, influenza spreads through droplets sneezed or coughed into the air, which makes it easier to catch.

But unlike most strains of flu, filoviruses kill large percentages of the people they infect, up to 90%. This is why this particular lab may be the most dangerous place on earth; it's dedicated exclusively to testing live samples of Ebola. If just a speck of Ebola virus enters your bloodstream, it can quickly make billions of copies of itself and rip you apart from the inside—a hideous and painful way to die.