However, 56,607 subjects (25.4%) were considered to be following alternative schedules. Of those, 20,412 of those subjects (36.1% of subset) were on restrictive schedule only, 16,877 subjects (29.8% of subset) were classified as selective refusals only, and 19,318 subjects (34.1% of subset) were classified as both restrictive and selective refusals of vaccinations.
The remaining 11,871 individuals (5.3%) in the study population were classified as following an “unknown” vaccination schedule.
Children who followed the routine schedule were far more likely to be up to date on their vaccinations than those following alternative schedules: 89.8% vs. 14.8%, respectively (P < .05). The most commonly missed or refused vaccines in the alternative cohort were rotavirus (78.8%), hepatitis B (13.1%), and pneumococcal conjugate vaccine (6.6%).
“Although parents and physicians may view an alternative schedule as the middle ground between the routine schedule and choosing not to vaccinate, intentional deviation from the routine schedule through an alternative schedule leaves children without adequate protection from vaccine preventable disease,” warned Dr. Nadeau and her coauthors, adding that “the reemergence of vaccine-preventable diseases, coupled with increasing proportions of children using an alternative schedule, may set the stage for more widespread outbreaks of vaccine-preventable diseases.”
The authors reported that the study was supported by funding from the Centers for Disease Control and Prevention, but made no other relevant financial disclosures.