When DS turned 1 I refused the chicken pox vaccine. I had no "real" reason other than I didn't think he needed it, I want him to get the chicken pox while he's a child. I was wandering around on the CDC website and found out the chicken pox shot has MSG in it---- DS is allergic to MSG. <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/bigeyes.gif" style="border:0px solid;" title="bigeyes"> Phew. Glad I listened to myself on that one. He's also allergic to the flu shot, yellow fever shot, and possibly the MMR (that one contains egg but it might also have corn, I've got to look up another ingredient).