I love keeping these on hand all year round. I'm a stay-at-home mom, so our daughter doesn't get subjected to all the germs at daycare. If I know she is going to be around a bunch of people at a party, or comes with me grocery shopping during the winter months, I make sure that I give her a dose before bedtime. She is rarely sick, so I'm convinced they must be working! My only drawback is that they are kind of expensive if you want to use them every day.