Childhood Immunization Rates Remain Stable
Childhood immunization rates in the United States remain stable at high levels, according to data from CDC's 2008 National Immunization Survey (NIS) published in this week's Morbidity and Mortality Weekly Report (MMWR).
“Vaccination is one of the most important things parents can do to protect their children's health,” said Dr. Melinda Wharton, Deputy Director, National Center for Immunization and Respiratory Diseases. “Thanks to the hard work of doctors and nurses and other immunization providers and the commitment of parents, rates are still high, but we must all continue to work hard to reach those children who are not fully vaccinated.”
The 2008 NIS included children aged 19–35 months and born during January 2005–June 2007.
Among these children, coverage was 76.1 percent with the 4:3:1:3:3:1 series of vaccines, not a statistically significant difference from the 2007 estimate of 77.4 percent. The national goal for coverage with the 4:3:1:3:3:1 series is 80 percent.
Vaccines in the series are:
* Four or more doses of diphtheria, tetanus and pertussis vaccine (DTaP)
* Three or more doses of polio vaccine
* One or more doses of measles, mumps and rubella vaccine (MMR)
* Three or more doses of Haemophilus influenzae type b vaccine (Hib)
* Three or more doses of hepatitis B vaccine
* One or more doses of varicella (chickenpox) vaccine
For each vaccine in the series, the goal is 90 percent and this was met, except for four doses of DTaP vaccine, which was 84.6 percent.
The 2008 NIS data showed a small but statistically significant decrease nationally for coverage with the Hib vaccine. In 2007, coverage with three or more doses of Hib was 92.6 percent and in 2008 coverage was 90.9 percent. This decrease is likely due to a shortage of the vaccine that began in December 2007 and a temporary recommendation to defer the booster dose. At least 8 percent of the children in the survey were likely impacted by this recommendation. More vaccine became available this summer, and the booster dose is now being recommended again for children at age 12–15 months.
In 2008, coverage with three or more doses of doses of pneumococcal conjugate vaccine (PCV7) increased from 90.0 percent to 92.8 percent and coverage with four or more doses increased from 75.3 percent to 80.1 percent.
As in previous years, estimated vaccination coverage levels varied substantially among states and local areas. 4:3:1:3:3:1 state coverage ranged from 59.2 percent in Montana to 82.3 percent in Massachusetts. Coverage also varied among the 17 local areas surveyed, from 68.5 percent in Northern California to 80.9 percent Santa Clara County, Calif.
This is the first NIS report to include coverage for two or more doses of hepatitis A vaccine, which was 40.4 percent. This report also includes coverage among newborns with the first dose of the hepatitis B vaccine, which was 55.3 percent, an increase from 53.2 percent in 2007.
The proportion of children who had received no vaccine doses remained at 0.06 percent.
Among racial/ethnic groups, little variation in coverage was observed. Coverage for most vaccines remained lower for children living below poverty than children living at or above poverty. Sustaining high coverage levels and finding effective methods of reducing disparities across states/local areas and income groups remains a priority to fully protect children and limit the incidence of vaccine-preventable diseases in the United States.
The NIS is an ongoing random-digit dialed survey of households with children aged 19-35 months. It also includes a mail survey of the children's vaccination providers to collect vaccination information. During 2008, 18,430 children with provider-reported vaccination records were included in this report.