A nationally representative sample of infants is 19 to 35 months of age. The data were collected from 308,524 immunization registries at the total 246 public health centers. We used the data of immunization date, immunization institution, age, gender, birth order, and etc. The timeliness of immunization standards are using the standard of KCDC (Korea Centers for Disease Control & Prevention) and ACIP (Advisory Committee on Immunization Practices, American Academy of Pediatrics and American Academy of Family Physicians). According to the Standards of KCDC, timeliness of immunization rates were the lowest in hepatitis B (1st) and the highest in polio vaccine (1st). According to the Standards of ACIP, timeliness of immunization rates were the highest in polio vaccine (1st). Timeliness of immunization rate for each vaccination showed little differences by gender according to the Standards of KCDC and ACIP. Timeliness of immunization rates in KCDC and ACIP Standards in birth order were the highest hepatitis B (1st), DTaP (2nd, 3rd, 4th), polio (2nd, 3rd) and varicella in the first baby and hepatitis B (2nd), DTaP (1st) and polio (1st) were the highest in the second baby. According to the standards of KCDC and ACIP, the age from 19 months to 24 months were the highest in BCG, hepatitis B (1st, 2nd), DTaP (1st, 2nd, 3rd, 4th), polio (1st, 2nd, 3rd) and varicella. Timeliness of immunization rates in regional group were the highest in all vaccinations in large cities except hepatitis B (1st, 2nd) and varicella. After analyzing * *
