BACKGROUND:
To be fully protected, children must complete the 4:3:1:3:3 series (4 or more doses of diphtheria and tetanus toxoids and pertussis vaccine, or diphtheria and tetanus toxoids [DTP/DTaP/DT], 3 or more doses of poliovirus vaccine, 1 or more doses of measles-containing vaccine, 3 or more doses of Haemophilus influenzae type b vaccine, and 3 or more doses of hepatitis B vaccine). Children who are not fully vaccinated can miss one or more than one doses from this series. Children missing one dose might be more readily brought to series completion than those missing multiple doses.

OBJECTIVE:
To determine if demographics of children 19 to 35 months old are associated with being within one dose of series completion.

METHOD:
The National Immunization Survey (NIS) measures vaccination coverage of US children 19 to 35 months old. We used national level 2002 NIS data to compare demographics of children one dose short for either 4:3:1:3:3 or 3:3:1:3:3 (4:3:1:3:3, but with 3+ doses of DTP/DTaP/DT) with those of children who were two or more doses short.

RESULT:
Most demographic factors (race/ethnicity; maternal education; urbanicity; and poverty status) of children missing one dose (4:3:1:3:3 or 3:3:1:3:3) were not statistically significantly different from those of children missing multiple doses. ‘Foreign born’ status was the only statistically significantly difference found (foreign born children were more likely to miss multiple doses.)

CONCLUSION:
Among series incomplete children, the demographic factors mentioned above are of little use in identifying children lacking only one dose.

LEARNING OBJECTIVES:
To determine if children one vaccine dose short of being fully protected can be easily identified.