Vaccination Coverage among Children in Kindergarten, 2011-2012

In late 2010, the US Department of Health and Human Services unveiled Healthy People 2020, a program outlining 10-year goals and objectives for health promotion and disease prevention. Maintaining vaccination coverage among children in kindergarten in the United States is one of the goals of the program, along with increasing the number of states, and the District of Columbia (DC), that collect data on kindergarten vaccination coverage in accordance with minimum standards set by the Centers for Disease Control and Prevention (CDC).

In 2011, the CDC reported 17 outbreaks of measles and 222 measles cases; most were imported cases in persons who were not vaccinated. The numbers were the highest in the United States since 1996. Highlighting the importance of monitoring measles vaccination coverage at the local level, the CDC Morbidity and Mortality Weekly Report [August 24, 2012/61(33):647-652], summarizes vaccination coverage, exemption rates, and reporting methods from the 2011-2012 school year. Kindergarten vaccination assessments were submitted by 56 granteees, including 49 states, DC, 1 city, and 5 other reporting areas.

Median coverage of 2 doses of measles, mumps, and rubella (MMR) vaccine was 94.8% among 47 reporting states and DC. The total exemption rates, including medical, religious, and philosophic exemptions, among 49 reporting states and DC, ranged from <0.1% to 7.0% (median, 1.5%).

The coverage target is ≥95% vaccination coverage for the following vaccines: MMR; diphtheria, tetanus toxoid, and acellular pertussis (DTaP); poliovirus; hepatitis B (HepB); and varicella. The reporting target is all 50 states and DC collecting data on kindergarten vaccination coverage in accordance with CDC minimum standards.

Vaccination status of children in kindergarten was considered up-to-date if they had received all of the vaccine doses required for school entry in their state or area. All reporting grantees required 2 doses of MMR vaccine and 3 or 4 doses of poliovirus vaccine. School entry requirements for other vaccinations varied buy grantee: 52 grantees required 4 or 5 doses of DTaP vaccine, 50 required 3 doses of HepB vaccine, and 13 required 1 dose and 37 required 2 doses of varicella vaccine.

Types of exemptions and processes for obtaining exemptions also varied by grantee. All of the reporting grantees allowed medical exemptions, 47 allowed religious exemptions, and 20 allowed philosophic exemptions. Mississippi and West Virginia did not allow exemptions for religious or philosophic reasons.

Overall, among grantees in the 49 states and DC that reported vaccination coverage for the 2011-2012 school year, median MMR coverage was 94.8% (range, 86.8% in Colorado to 99.3% in Texas). Among 33 grantees reporting varicella vaccination coverage, median coverage with 2 doses was 93.2% (range, 84.0% in Colorado to 99.2% in Mississippi and Texas). Median coverage levels for DTaP, poliovirus, and HepB were all at or above the Healthy People 2020 target of 95%.

Among grantees in the 49 states and DC that reported exemptions, 10 reported <1% and 9 reported >4% total exemption rates (range, <0.1% in Mississippi to 7.0% in Alaska). An estimated 89,133 exemptions were reported for a total estimated population of 4,124,185 children in kindergarten.

The median total exemption level was 1.5%, a median increase of 0.2 percentage points compared with the 2009/2010 school year. Arkansas reported the largest increase in exemption level (3.4 percentage points); Nebraska reported the largest decrease (2.3 percentage points).

“Sustaining high vaccination coverage among school children is vital to prevent outbreaks and avoid reestablishment of diseases that have been eliminated in the United States…Assessing vaccination coverage compliance with local requirements and exemption levels as children enter kindergarten is essential for identifying and addressing areas of undervaccination and reducing outbreaks of vaccine preventable disease and accompanying morbidity and morality," the report stated.