Carpiano RM, et al. - Researchers determined the degree to which Canadian parents' vaccination knowledge, attitudes, and beliefs (KAB) and child vaccination receipt could be determined by family socioeconomic status (SES) (parent education, household income). They also investigated if there exists an indirect link between SES and receipt via KAB. For this purpose, they analyzed different age groups of children and vaccinations by utilizing 2013 Childhood National Immunization Coverage Survey (CNICS) data. Across the three age groups (at age 2, at age 7 and at ages 12–14), inconsistent associations of SES with KAB and vaccine receipt were found. Vaccine-specific side effect and safety concerns accounted for SES disparities in KAB. Higher odds of being concerned were noted in relation to lower education and income levels. Concerns regarding vaccine efficacy [DPT (diphtheria, pertussis, and tetanus), HPV (human papillomavirus)] and side effects [MMR (measles, mumps, and rubella), HPV] and lower perceived value of immunizing a child (MMR, HPV) were noted in association with non-receipt of minimum age-specific vaccination dosages. In MMR, KAB mediation was mostly limited to SES patterns.