The flu is a much worse deal than a cold. But it is also caused by a virus. We have heard so much about antibiotic overuse lately. Antibiotics work only on bacteria not viruses. That is absolutely correct.
Antibiotics work only on bacteria.
Bacteria and viruses are essentially very different types of bugs. Bacteria are organisms that reproduce and multiply on their own inside the body, like your throat as in strap throat. They are relatively large organisms and antibiotics can easily find and kill them. Viruses on the other hand are much smaller and multiply inside the cells of the body. They are harder to find and harder to destroy and that is at the root of why antibiotics and other drugs don't work on viruses.