I thought about taking the echinacea but when I asked my doctor about it he told me colds are virus not bacterial so nothing will prevent them but things like freguent hand washing expecially when sneezing, coughing or being around people who are keeps the persons natural immune system up so that they are less likely to catch colds, not getting over tired by making sure the person gets at least 7-8 hours sleep a night also help the bodys natural immune system as does a properly balanced diet that is right for the person that will keep all the vitamins, minerals and blood counts where they should be, 64 fluid ounces of plain water a day also helps to flush the body and keeps the cells growing and producing virus and bacterial fighting white blood cells. He said echinacea shouldnt be taken by people who already have a good blood count for vitamins, minerals and other blood counts because it changes the rate of production on red blood cells. too many causes certain blood deseases and too little causes another kind of blood deseases. those with certain health problems or conditions like pregnancy, anemia and cancer should not be taking echinacea or any other over the counter medications with out consulting with the physician first. Thanks for the idea though.