Table 3. Estimated linear trends in vaccination coverage by age 24 months, National Immunization Survey-Child, United States, 

2013–2017

Monthly Birth Cohorts (A) 

January 2012–January 2016

Monthly Birth Cohorts (B) 

January 2014–January 2016

Vaccine/Dose Estimate Lower CI Upper CI Estimate Lower CI Upper CI

DTaP*

≥3 doses Baseline coverage† 95.18 94.54 95.83 93.28 90.42 96.14

12-month change§ -0.29 -0.59 0.01 0.30 -0.65 1.25

≥4 doses Baseline coverage 82.49 81.07 83.91 81.71 75.16 88.26

12-month change -0.55 -1.20 0.10 -0.23 -2.42 1.96

Poliovirus (≥3 doses) Baseline coverage 93.45 92.71 94.20 89.66 85.79 93.52

12-month change -0.17 -0.52 0.18 1.05 -0.21 2.31

MMR (≥1 dose) Baseline coverage 91.34 90.33 92.34 93.46 89.59 97.33

12-month change -0.11 -0.58 0.35 -0.88 -2.19 0.43

Hib¶

Primary series Baseline coverage 94.56 93.81 95.30 93.06 90.02 96.10

12-month change -0.50 -0.86 -0.14 -0.07 -1.09 0.95

Full series Baseline coverage 81.53 80.19 82.88 81.97 76.13 87.81

12-month change -0.51 -1.13 0.11 -0.65 -2.61 1.31

HepB

≥3 doses Baseline coverage 93.29 92.37 94.21 89.87 86.19 93.56

12-month change -0.53 -0.97 -0.09 0.58 -0.65 1.80

Birth dose** Baseline coverage 72.67 71.14 74.20 65.40 60.05 70.76

12-month change 0.58 -0.10 1.26 2.97 1.22 4.73

Varicella (≥1 dose) Baseline coverage 90.69 89.66 91.72 90.73 86.56 94.90

12-month change -0.05 -0.53 0.42 -0.14 -1.54 1.26

PCV

≥3 doses Baseline coverage 93.42 92.62 94.22 92.30 88.25 96.35

12-month change -0.18 -0.55 0.19 0.19 -1.17 1.55

≥4 doses Baseline coverage 82.50 80.97 84.03 83.61 75.96 91.26

12-month change 0.00 -0.69 0.68 -0.33 -2.88 2.22

HepA

≥1 doses Baseline coverage 83.14 82.00 84.28 83.05 78.76 87.35

12-month change 0.44 -0.07 0.96 0.46 -0.98 1.90

≥2 doses Baseline coverage 39.56 37.77 41.34 45.29 38.79 51.79

12-month change 1.13 0.30 1.97 -0.76 -2.95 1.44

≥2 doses (by 35 months)†† Baseline coverage 75.26 72.34 78.19 85.76 68.93 102.60

12-month change -0.42 -1.96 1.12 -4.39 -10.77 1.98

Rotavirus (by 8 months)§§ Baseline coverage 71.87 70.17 73.57 73.47 66.87 80.07

12-month change 0.68 -0.09 1.45 0.15 -2.08 2.38

Combined 7-vaccine series¶¶ Baseline coverage 69.44 67.67 71.20 69.82 61.69 77.96

12-month change -0.27 -1.07 0.53 -0.33 -3.05 2.40

Abbreviations: CI = confidence interval; DTaP = diphtheria, tetanus toxoids, and acellular pertussis vaccine; HepA = hepatitis A vaccine; HepB = 

hepatitis B vaccine; Hib = Haemophilus influenzae type b conjugate vaccine; MMR = measles, mumps, and rubella vaccine; PCV = pneumococcal 

conjugate vaccine

Bolded estimates of 12-month change in coverage are statistically significant at p<0.05, where the 95% CI does not contain zero.

* Includes children who might have been vaccinated with diphtheria and tetanus toxoids vaccine or diphtheria, tetanus toxoids, and pertussis vaccine. † Estimated vaccination coverage for the oldest monthly birth cohort included in the linear regression analysis (the estimated intercept for the fitted linear 

regression line).

§ Percentage point change in coverage over 12 months of birth, estimated as the per-month-of-birth slope of the fitted regression line*12. ¶ Hib primary series: receipt of ≥2 or ≥3 doses, depending on the product type received. Full series: receipt of ≥3 or ≥4 doses, depending on product type 

received (primary series and booster dose).

** The hepatitis birth dose (one dose of HepB administered between birth and age 3 days) was assessed by age 3 days. Estimates for the group A 

monthly birth cohorts are based on data from children born January 2012 through May 2016. Estimates for the group B monthly birth cohorts are based 

on data from children born January 2014 through May 2016. †† ≥2 doses of HepA vaccine was also assessed at 35 months, since a child could follow the recommended schedule and still receive vaccine at this age. 

Estimates for the group A monthly birth cohorts are based on data from children born January 2012 through February 2015. Estimates for the group B 

monthly birth cohorts are based on data from children born January 2014 through February 2015.
§§ Rotavirus vaccine was assessed at 8 months since the age at vaccination should not exceed 8 months. Estimates for the group A monthly birth cohorts

are based on data from children born January 2012 through May 2016. Estimates for the group B monthly birth cohorts are based on data from children 

born January 2014 through May 2016. ¶¶ The combined 7-vaccine series includes ≥4 doses of DTaP, ≥3 doses of poliovirus vaccine, ≥1 dose of measles-containing vaccine, the full series of 

Hib (≥3 or ≥4 doses, depending on product type of vaccine), ≥3 doses of HepB, ≥1 dose of varicella vaccine, and ≥4 doses of PCV.