Vaccination coverage among children entering school—United States, 2005-06 school year

Morbidity and Mortality Weekly Report, Oct 20, 2006 by C. Stanwyck, J. Davila, B. Lyons, C. Knighton

One of the national health objectives for 2010 is to achieve and sustain [greater than or equal to] 95% vaccination coverage among children in kindergarten through first grade for the following vaccines: hepatitis B vaccine; diphtheria and tetanus toxoids and pertussis vaccine, diphtheria and tetanus toxoids and acellular pertussis vaccine, or diphtheria and tetanus toxoids vaccine (DTP/DTaP/DT); poliovirus (polio) vaccine; measles, mumps, and rubella vaccines; and varicella vaccine (1). To determine vaccination coverage among children entering kindergarten, data were analyzed from reports submitted to CDC by states and the District of Columbia (DC) for the 2005-06 school year. This report summarizes the results of that analysis, which indicated that coverage for each vaccine was reported to have exceeded 95% in more than half of the states (Table 1).

For the 2005-06 school year, DC and all states except two (Illinois and Wyoming) submitted reports of vaccination coverage levels for children entering kindergarten. Of these, 49 reports included coverage for polio vaccine, DTP/DTaP/DT vaccine, measles-containing vaccine, and rubella-containing vaccine; 46 reports included coverage for mumps-containing vaccine; 43 reports included coverage for hepatitis B vaccine; and 41 reports included coverage for varicella vaccine (Table 2).

All states based their assessments, in part, on public schools; in addition, 47 states assessed private schools, and 17 states assessed home schools. In 2005-06, 11 states reported assessments based on 100% of children entering kindergarten in public, private, and home schools; in the 2004-05 school year, five state reports included all school types (2). Although many states conducted a census of all students in the schools they assessed, five states selected a random sample of schools, students, or both to determine coverage rates. Health departments reviewed immunization records to assess coverage in six states, relied on self-reported coverage from schools in 29 states, and used some other methodology (e.g., reports from health departments and school personnel) in 14 states.

Four of the eight U.S. territories that receive federal immunization grants also reported data for the 2005-06 school year. All four reports included coverage for polio vaccine; DTP/DTaP/DT vaccine; measles, mumps, and rubella vaccines; and hepatitis B vaccine (Table 2). Two U.S. territories reported coverage for varicella vaccine. The percentage of children surveyed by the U.S. territories ranged from 10% to 100%. Both public and private schools were included in the assessments, and varying methods were used to assess coverage (e.g., self-reports, health department audits, and vaccination registries).

To determine coverage, state or territory up-to-date status was used rather than number of doses received because the number of doses required to be up-to-date varies depending on timing of vaccinations, area requirements regarding number of doses, and brand of vaccines. National and territorial estimates of coverage were calculated by weighting each state's or territory's coverage estimate according to the size of the kindergarten enrollment for 2005-06.

Coverage for the newest recommended vaccine included in the assessment, varicella, was reported as [greater than or equal to] 95% in 29 (57%) states and DC and [greater than or equal] 90% in 36 (71%) states and DC (Table 1). Coverage for other vaccines was higher, ranging from 31 (61%) states with [greater than or equal to] 95% coverage for measles and hepatitis B vaccines, to 34 (67%) states with [greater than or equal to] 95% coverage for DTP/DTaP/DT vaccine.

Varicella coverage was <95% in the two territories (Puerto Rico [89%] and the Virgin Islands [88%]) that reported varicelia coverage. Vaccination coverage [greater than or equal to] 95% was reported for hepatitis B by Mariana Islands and Puerto Rico. Coverage levels in the reporting territories for all other vaccines were <95%.

Editorial Note: More than half of reporting states indicate that they have already reached the Healthy People 2010 goal of [greater than or equal to] 95% coverage for each of the vaccines recommended by the Advisory Committee on Immunization Practices (ACIP); the remaining states are making progress toward this goal. However, required vaccines and methods for surveying kindergarten-aged children vary substantially from state to state; the majority of states rely on self-reports by schools, rather than audits by health departments, to determine coverage, which might lead to underestimations or overestimations. CDC provided a new online reporting system, which has been available since the 2002-03 school year, to help states and U.S.-affiliated jurisdictions collect and report data on vaccination coverage among children entering school. Anecdotal reports from states indicate that this system, which automates data-management and calculation tasks, has made reporting coverage easier. CDC also has promoted greater standardization of reporting, for example, by encouraging all states to report coverage based on ACIP recommendations rather than on state requirements (3). These improvements in survey methods and assessment procedures will help ensure that health jurisdictions are accurately reporting progress toward the [greater than or equal to] 95% coverage goal.