Book Quotes: Colds are caused by viruses

I haven't read this book (beyond a short excerpt), but I thought people would like to know this short quote from AH-CHOO! by Jennifer Ackerman from pages 14-15:

[Colds] are not [caused by] bacteria, as some of the boys seem to think, but viruses. This is why antibiotics have no effect on colds. Zip. Nil. Antibiotics kill bacteria by preventing them from building their cell walls. Viruses are not cells and have no cell walls, so they're utterly unaffected by the drugs. This is also why those antibacterial soaps, shampoos, and lotions have no effect on cold germs. Promotional claims notwithstanding, these products will do nothing to protect you, your friends, or your family from contracting a cold.