There are a number of things you can do to boost your immune system, which can help you get sick less often.Strengthening your immune system can help reduce your frequency of catching colds, and even reduce their severity. There are tons of supplements marketed as immune boosters, but what does the scientific literature say? Research shows when you haven’t been getting enough sleep or the right nutrition, your immune system can’t function optimally to defend against illnesses. Rather than loading up on supplements when you feel a cold coming on, the best way to strengthen your immune system is to keep it healthy and strong in the first place.