are more likely to suffer adverse effects from particular immunizations, such as MMR and the varicella vaccine (IOM, 2012).

During each of the three public sessions held in conjunction with committee meetings, the testimony of many individuals and organizational representatives revealed a lack of trust in the quality and thoroughness of vaccine safety research. Several individuals recommended that the committee review the scientific studies that have compared health outcomes among fully vaccinated, partially vaccinated, and unvaccinated children as well as children who have been vaccinated according to alternative schedules.

The comments that were submitted through an online questionnaire in response to the committee’s commissioned paper (see Appendix D) echoed many of the concerns and suggestions that were articulated during the three public sessions. The sentiments largely focused on the concern that the recommended immunization schedule bombards children’s immune systems with an excessive number of antigens at an early age and may not be as safe as possible.


As indicated by the high rates of vaccination coverage, most American parents believe that vaccinations are an effective way to protect their children from serious infectious diseases (CDC, 2012). Despite this strong support, parents have concerns, questions, and misperceptions about childhood immunizations (Kennedy et al., 2011b). Parents seek information about vaccine safety from a multitude of sources: public health authorities, pediatricians, other child health care professionals, professional organizations’ websites, personal blogs, celebrities, and advocacy groups (Freed et al., 2011).

With such a wide range of sources of information about immunizations, the committee recognized the likelihood that parents could receive conflicting information that could exacerbate their concerns and confusion about the safety of vaccines. The committee also noted the many high-quality websites and materials that have recently been produced, including and materials produced by the American Academy of Pediatrics (AAP) and available on the AAP website. However, findings from an online survey conducted as part of an ongoing study of 2,521 parents and nonparents demonstrated that although websites from doctors’ groups, such as AAP, and government websites were trusted by the greatest proportion of surveyed parents (27 and 7 percent, respectively), a larger proportion did not view or use these resources at all (29 and 38 percent, respectively) (Freed et al., 2011).

Apart from the confusion associated with conflicting sources of information about childhood vaccines (Freed et al., 2011), the committee’s

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