I think the word 'germ' is from before we knew there were viruses, so I think it's ok to use 'germs' to mean only bacteria.

Also, viruses aren't exactly alive, so they can't exactly be killed. They need to be inside a living thing - a living organism - in order to reproduce. I think the hand sanitizer would probably disrupt a lot of their protein coats and prevent them from getting into our cells.

I think hand sanitizer is good for times when you don't have soap and water. Even if it's only as good as washing with soap and water, hand sanitizer works without using all the water and towels we need to wash our hands.

Also, we don't need to remove all our germs and viruses. Our immune systems get strong by being exposed to low levels of germs and viruses. So we only need to remove most of the germs and viruses to protect ourselves from them.

Keep asking questions! Wikipedia has an article on hand sanitizer, and here's another link that asks the same question as you do:

Hand Sanitizers vs. Soap and Water handsanitizer

Antibacterial hand sanitizers are marketed to the public as an effective way to "wash one's hands" when traditional soap and water are not available. These ...

Check out these sites to see how they agree or disagree with my answer!

The 99.9% effectiveness claim made by hand sanitizer companies is based on laboratory tests that they have done. Thus it is a hard comparison to make to what goes on in the real world. In the real world, human hands are not smooth surfaces. We have pits and grooves where bacteria and viruses can hang out. We also may wear jewelry or watches, which also carry a lot of germs. We are also constantly touching our faces, which will transfer germs. It is true that hand sanitizers do not work on every single bacterial and viral species out there. However, it can reduce the load of bacteria and some viruses. Thus, it can help to prevent the spread of potentially harmful bacteria and viruses. One thing that definitely reduces the effectiveness of hand sanitizers is if your hands are visibly dirty. The dirt can help the bacteria hide from the sanitizer and prevent the alcohol from fully penetrating the cell. Hand washing is also not necessarily 100% effective either. People may not wash their hands long enough or hit places like between their fingers or under their nails. If you touch the handle of the paper towel dispenser, the sink, or the bathroom door you can reinoculate yourself with bacteria.

Hand sanitizers are definitely effective in killing microorganisms, which is what the term "germs" implies. Viruses, although dangerous, are not considered living organisms. Also, washing your hands thoroughly is always better than using a hand sanitizer, since you scrub off anything (viruses, bacteria, etc.) that may be on your hands.