Buzz
Franklin Veaux:
There is no clear distinction, since viruses aren't considered alive.
Viruses exist in a gray area between life and death. This is why scientists refer to them as "inactivated" or "attenuated" viruses, rather than calling them "dead" viruses.
Think of a virus as a machine. In many ways, it's simpler than a car. What's the difference between a live car and a dead one? Nothing, since cars aren't alive.
Cars can either be operational or broken. For instance, you could disconnect the spark plugs, empty the gas tank, or clog the intake with Silly Putty, and the car would stop running, even though it appears the same.
Inactivated viruses are like broken cars: something in their machinery has been altered or harmed, making them nonfunctional.
You can render viruses inactive by applying heat to damage their protein shell or by destroying their genetic material. Radiation can also be used to damage their genetic code. You might even break the virus into smaller pieces.
Your immune system doesn't identify the whole virus; instead, it targets certain parts known as "antigens" or "antigen subunits." As long as that part remains intact, the rest of the virus's damage doesn't matter to the immune response.
To illustrate, imagine opening the hood of a car, turning the engine into molten metal, and then closing the hood. People walking by will still recognize it as a car. They’ll glance at it and say, "yep, that’s a car," even though the engine is completely destroyed. You could even remove the wheels, and they would still confirm, "yep, that’s a car."
Your body will look at a virus’s outer structure and recognize it as a virus, even if its genetic material is completely destroyed (or entirely removed). You can strip off parts of the virus, and your body will still acknowledge it as a virus.
This post originally appeared on Quora. Click here to view.
