Viruses are very small germs that can get inside us and make us sick. A virus can give us colds, or cause diseases like chickenpox, the flu and COVID-19.
But are these tiny pathogens alive?
This seems like a straightforward question until you think about what it means to be alive. When we talk about living things, we are usually talking about things that are born, breathe and grow. Living things can reproduce, make their own energy, and respond and adapt to their environment.
Can viruses do all these things? Not really. Viruses can't reproduce on their own unless they infect a cell. They turn the host cell into a virus "factory" by instructing it to make more of the virus. Without a host cell, this can't happen. And while a virus does not have its own energy, it can use the host cell's energy. They use that to fire up their virus factories. Does this qualify as life? What do you think?
Most scientists agree that viruses are not alive. Some disagree, pointing to recently discovered giant viruses which have genes for metabolism (chemical reactions that use or release energy). Whether they're alive or not, viruses are capable of making us sick! So remember to wash your hands frequently and cover your cough and sneeze. Let's try to shut down these virus factories before they start!
Learn more about viruses and what you can do to stay healthy with these books!