If you get two of these, sorry, my hand slid off the keyboard and this post seems to have disappeared...
Thanks for the referral to the U. Conn study and I have a few comments to add to this new thread. As a western-trained immunologist with complementary leanings and gleanings I've followed the echinacea (EC) studies for years.... so first of all, who SHOULDN'T take it, are people with autoimmune diseases or AIDS. Why, EC acts by activating the immune system. These folks already have systems that are activated inappropriately.
Second, the recommendation was not for us to begin dosing ourselves with EC to prevent colds, it was for more research - which plant was best, dosage, etc. In the past the recommendation was to only take EC at the first sign of symptoms, which I would guess still holds until we know more. It has been shown, for sure, to shorten the time we have symptoms.
Third, know the source of what you're taking if you do take it. Check out consumerlab.com which is an unbiased company that analyzes supplements, herbs, vitamins, etc for content amounts and contaminants. You can subscribe to them for about $30/yr and get all their past and future reports. Since these substances are not regulated by FDA we have no guarantee what's in the bottle, not that I want the government involved, but someone has to protect the consumer. Information is a great protector.
finally, boy, this got long - I wouldn't get in the habit of taking EC all the time since it does stimulate the immune system and more of our illnesses these days are from overstimulated systems, there is risk with this simple herbal.