To the OP, here is some information that may put your mind at ease: (There are also some related articles on the website you may be interested in) http://www.sciencedaily.com/releases/2011/03/110304091458.htm Vaccinated Children Not at Higher Risk of Infections or Allergic Diseases, Study Suggests ScienceDaily (Mar. 7, 2011) Do vaccinations put too much strain on or weaken children's immune systems? Roma Schmitz and her colleagues from the Robert Koch Institute investigate exactly this research question in the current issue of Deutsches rzteblatt International. Their data are based on the results of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). In their study, the authors compare the occurrence of infections and allergies in vaccinated and unvaccinated children and adolescents. These include bronchitis, eczema, colds, and gastrointestinal infections. The evaluation showed that unvaccinated children and adolescents differ from their vaccinated peers merely in terms of the frequency of vaccine preventable diseases. These include pertussis, mumps, or measles. As expected, the risk of contracting these diseases is substantially lower in vaccinated children and adolescents.