We had our first son vaccinated when he was a baby and after every one he seemed to get some illness that required medical attention and it was always accompanied with breathing problems. It finally hit us what that he was reacting and we stopped them. He had eczema, allergies and asthma and our doctor said that he probably had a predisposition to all three but that the vaccines probably made them all worse and to show up at an earlier age. He is seven now and still gets sick alot. Our second son never had any and does not have ANY issues. He is hardly ever sick and has no allergies or signs of asthma.
If you are interested in reading about reactions then the government maintains a site that keeps track of them: vaers.com. Just remember that they estimate that only 10% of the reactions are reported, so it is quite a bit more, it is a very large list! If you are questioning vaccines, then you should also know that they are NOT mandatory for school, Michigan has three exemptions, religious, philosophical and medical. You can find the forms for filing these exemptions, free of charge, and other information at: http://www.momvaccines.org/ which is a group based in Michigan. I have filed exemptions for my older son for school and for my younger son for daycare/preschool and have not had any problems.
Good luck!