National, State, and Local Area Vaccination Coverage Among Children Aged 19–35 Months — United States, 2012

The National Immunization Survey (NIS) is a random-digit–dialed telephone survey used to monitor vaccination coverage among U.S. children aged 19–35 months. This report describes national, state, and selected local area vaccination coverage estimates for children born during January 2009–May 2011, based on results from the 2012 NIS. Healthy People 2020* objectives set childhood vaccination targets of 90% for ≥1 doses of measles, mumps, and rubella vaccine (MMR); ≥3 doses of hepatitis B vaccine (HepB); ≥3 doses of poliovirus vaccine; ≥1 doses of varicella vaccine; ≥4 doses of diphtheria, tetanus, and pertussis vaccine (DTaP); ≥4 doses of pneumococcal conjugate vaccine (PCV); and the full series of Haemophilus influenzae type b vaccine (Hib). Vaccination coverage remained near or above the national Healthy People 2020 target for ≥1 doses of MMR (90.8%), ≥3 doses of poliovirus vaccine (92.8%), ≥3 doses of HepB (89.7%), and ≥1 doses of varicella vaccine (90.2%). Coverage increased from 68.6% in 2011 to 71.6% in 2012 for the birth dose of HepB.† Coverage was below the Healthy People 2020 target and either decreased or remained stable relative to 2011 for ≥4 doses of DTaP (82.5%), the full series of Hib (80.9%), and ≥4 doses of PCV (81.9%). Coverage also remained stable relative to 2011 and below the Healthy People 2020 targets of 85% and 80%, respectively, for ≥2 doses of hepatitis A vaccine (HepA) (53.0%), and rotavirus vaccine (68.6%). The percentage of children who had not received any vaccinations remained 15 weeks, and the final dose should be given by age 8 months (5). These age restrictions might preclude infants from starting or completing the series. Health-care providers should make every effort to start and complete administration of the rotavirus vaccine series on time.

Although few differences in coverage by racial/ethnic group were observed after adjustment for poverty status, differences in coverage by poverty level remained for many vaccines. The Vaccines For Children program¶¶¶ has been successful in removing differences in coverage between children living above and below the poverty level that once existed for vaccines such as MMR, polio, and HepB (6); however, coverage among children living below the poverty level still lags behind coverage of children living at or above the poverty level for newer vaccines (HepA and rotavirus) and vaccines that require 4 doses to complete the series.

Vaccination coverage continues to vary across states. Clusters of unvaccinated children leave communities vulnerable to outbreaks of disease. The continued occurrence of measles outbreaks among unvaccinated persons in the United States (7) underscores the importance of maintaining uniformly high coverage to prevent transmission of imported disease. Recent budget cuts to state and local health departments (8) as well as differences by state in factors such as population characteristics, immunization program activities, vaccination requirements for child-care centers, and vaccine financing policies might contribute to variations in vaccination coverage.

The findings in this report are subject to at least four limitations. First, the proportion of the NIS sampled by cellular telephone in 2012 was about half compared with only 11% in 2011 and zero in earlier years. Living in a household with only cellular telephone service is associated with poverty and other demographic factors that might be related to vaccination status (3). Second, underestimates of vaccination coverage might have resulted from the exclusive use of provider-reported vaccination histories because completeness of these records is unknown. Third, bias resulting from nonresponse and exclusion of households without telephone service might persist after weighting adjustments, although estimated bias from these sources for the 2011 NIS was low for selected vaccines examined, ranging from 0.3 (for MMR) to 1.5 (for ≥4 DTaP) percentage points (9). The potential for nonresponse bias was increased in 2012 because of the lower response rate for the cellular telephone sample. However, a comparison of vaccination coverage estimates from the NIS from July 2011 through June 2012 with those from the National Health Interview Survey during the same period yielded similar results, both overall and for children living in cellular-only households, despite largely different response rates between the two surveys (Assessment Branch, Immunization Services Division, National Center for Immunization and Respiratory Diseases, and Survey Planning and Special Surveys Branch, Division of Health Interview Statistics, National Center for Health Statistics, CDC; unpublished data; 2013). Finally, although national coverage estimates are precise, estimates for state and local areas should be interpreted with caution because of smaller sample sizes and wider confidence intervals.

High vaccination coverage among preschool-aged children has resulted in historically low levels of most vaccine-preventable diseases in the United States (1). The results of the 2012 NIS indicate that vaccination coverage among young children remained relatively stable and the proportion of children who do not receive any vaccinations has remained low. Slight decreases in coverage for some vaccines relative to 2011 cannot be immediately explained but could be attributable to a change in NIS methods. The 2012 results should be considered a baseline against which future trends in coverage can be evaluated. Careful monitoring of coverage levels overall and in subpopulations (e.g., racial/ethnic and geographic) is important to ensure that all children remain adequately protected. Parents and health-care providers should work to sustain high coverage and improve coverage for the more recently recommended vaccines and those that require booster doses after age 12 months. In addition to health system–based interventions previously described, national, state and local immunization programs should continue to partner with providers to implement the Guide to Community Preventive Services–recommended interventions aimed at increasing community demand for vaccination, such as client reminder/recall and client or family incentives. Enhanced access to health services also is recommended, through reduced out-of-pocket costs, home visits, and vaccination programs in child-care centers, schools, and Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) settings**** (4). Health insurance reforms of the Affordable Care Act require health plans to cover recommended immunizations without cost to the enrollee when administered by an in-network provider (10).††††

References

1. CDC. Vaccine-preventable diseases, immunizations, and MMWR—1961–2011. MMWR 2011;60(Suppl 4):49–57.
2. CDC. Updated recommendations for use of Haemophilus influenzae type b (Hib) vaccine: reinstatement of the booster dose at ages 12–15 months. MMWR 2009;58:673–4.
3. CDC. Wireless substitution: early release of estimates from the National Health Interview Survey, July–December 2012. Atlanta, GA: US Department of Health and Human Services, CDC; 2013. Available at http://www.cdc.gov/nchs/data/nhis/earlyrelease/wireless201306.pdf.
4. Community Preventive Services Task Force. Increasing appropriate vaccination: universally recommended vaccinations. In: The Guide to Community Preventive Services. Atlanta, GA: Community Preventive Services Task Force; 2013. Available at http://www.thecommunityguide.org/vaccines/index.html.
5. CDC. General recommendations on immunization: recommendations of the Advisory Committee on Immunization Practices (ACIP). MMWR 2011;60(No. RR-2).
6. CDC. Vaccination coverage by race/ethnicity and poverty level among children aged 19–35 months, United States, 1996. MMWR 1997;46:963–8.
7. CDC. Measles—United States, 2011. MMWR 2012;61:253–7.
8. Association of State and Territorial Health Officials. Budget cuts continue to affect the health of Americans: update March 2012. Arlington, VA: Association of State and Territorial Health Officials; 2012. Available at http://www.astho.org/display/assetdisplay.aspx?id=6907.
9. Pineau V, Wolter K, Skalland B, et al. Modeling total survey error in the 2011 National Immunization Survey (NIS): pre-school children and teens. Paper presented at 2013 Joint Statistical Meetings, August 3–8, 2013; Montreal, Quebec, Canada.
10. Patient Protection and Affordable Care Act. Pub. L. No. 111-48,124 Stat. 119 (2010).

What is already known on this topic?

Healthy People 2020 set childhood vaccination targets of 90% for ≥1 doses of measles, mumps, rubella vaccine (MMR); ≥3 doses of hepatitis B vaccine (HepB); ≥3 doses of poliovirus vaccine; ≥1 doses of varicella vaccine; ≥4 doses of diphtheria, tetanus, and pertussis vaccine; ≥4 doses of pneumococcal conjugate vaccine; and the full series of Haemophilus influenzae type b vaccine. The National Immunization Survey estimates coverage among U.S. children aged 19–35 months for these and other vaccines.

What is added by this report?

In 2012, childhood vaccination coverage remains near or above national target levels for ≥1 doses of MMR (90.8%), ≥3 doses of HepB (89.7%), ≥3 doses of poliovirus vaccine (92.8%), and ≥1 doses of varicella vaccine (90.2%); however, coverage varied by state and tended to be lower among children in families with incomes below the federal poverty level.

What are the implications for public health practice?

Sustaining current coverage levels and increasing coverage for those vaccines below national target levels is needed to maintain the low levels of vaccine-preventable diseases and prevent a resurgence of these diseases in the United States. Ensuring systems such as client reminder/recall and vaccination programs are in place in settings such as Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) clinics and child-care facilities can help support high vaccination coverage.

Vaccine and dosage

2008

2009

2010

2011

2012

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

Vaccine and dosage

Race/Ethnicity

Poverty level

White, non-Hispanic

Black, non-Hispanic

Hispanic

American Indian/Alaska Native

Asian

Multiracial, non-Hispanic

At or above

Below

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

State/Area

MMR (≥1 doses)

DTaP (≥4 doses)

HepB (birth)§

HepA (≥2 doses)¶

Rotavirus**

Combined series*

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

State/Area

MMR (≥1 doses)

DTaP (≥4 doses)

HepB (birth)§

HepA (≥2 doses)¶

Rotavirus**

Combined series*

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

%

(95% CI)

All MMWR HTML versions of articles are electronic conversions from typeset documents. This conversion might result in character translation or format errors in the HTML version. Users are referred to the electronic PDF version (http://www.cdc.gov/mmwr) and/or the original MMWR paper copy for printable versions of official text, figures, and tables. An original paper copy of this issue can be obtained from the Superintendent of Documents, U.S. Government Printing Office (GPO), Washington, DC 20402-9371; telephone: (202) 512-1800. Contact GPO for current prices.

**Questions or messages regarding errors in formatting should be addressed to mmwrq@cdc.gov.