Concerns that have been raised regarding vaccination of neonates and infants include: i) doubts about efficacy given the limited capacity of neonates to respond to many Ag; and ii) potential effects on immune system polarization, including potential for triggering autoimmunity via epitope mimickry or Aj effect [13, 14]. From a theoretical perspective, these concerns are in part mitigated by: i) the documented ability of newborns to respond to several vaccines including Bacillus Calmette Guérin (BCG) and hepatitis B vaccine (as outlined below), which serves as proof of concept that neonatal vaccination can be safe and effective and; ii) the presence of extensive immunologic mechanisms for central and peripheral tolerance that eliminates self-reactive T and B cells in newborns, coupled with; iii) evidence that multiple pediatric vaccines, including BCG, are not linked to allergy or autoimmunity [15]. Nevertheless, despite these conceptual reassurances, novel vaccines, as any new drugs, do have the potential of inducing side-effects and must certainly undergo rigorous and on-going safety analysis, including that provided in the U.S. by the Vaccine Adverse Event Reporting System (VAERS), a program of the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control (CDC). Indeed, safety concerns have prompted discontinuation and/or changes in some pediatric vaccines, with two examples discussed below.