So smoking is the worst thing! Because the white blood cells live in your lungs, when you breathe in smoke it can damage them. If you smoke for years, all the damage will stop the cells from working, so they cannot kill the bacteria that infects your lungs, and you end up with lots of infections, and your lungs start to break down. It is not a nice disease. I’m trying to find out how this happens to see if we can stop it.
Other things can also stop them. HIV infects the T cells, which are a type of white blood cell. It basically kills them off. If you don’t have any T cells, you can get really bad infections from bacteria or other viruses. This is why HIV is so bad, it destroys your immune system!