MMR and Varicella Vaccinations Fall Short in Some States

Emma Hitt, PhD

August 24, 2012

August 24, 2012 — Among kindergarten students, vaccination coverage met the Healthy People 2020 target of 95% or more in 2011-2012, with the exception of the measles, mumps, and rubella (MMR) vaccine and the varicella vaccine, which fell below this level in many states, according to the Centers for Disease Control and Prevention (CDC).

"Exemption levels were low overall, but clusters of unvaccinated children might exist at the school or community level," Stacie M. Greby, DVM, from the Immunization Services Division of the CDC's National Center for Immunization and Respiratory Diseases, and colleagues report in an article published in the August 24 issue of the Morbidity and Mortality Weekly Report.

In the 47 states and the District of Columbia that reported 2011 to 2012 school vaccination coverage, median MMR vaccination coverage was 94.8%, ranging from 86.8% coverage in Colorado to 99.3% in Texas. Of the reporting states, 4 states (Colorado [86.8%], Idaho [89.2%], Kansas [88.2%], and Pennsylvania [86.9%]) reported less than 90% MMR coverage.

In addition, median coverage with 2 doses of varicella vaccine among 33 reporting locations was 93.2%, ranging from 84.0% in Colorado to 99.2% in Mississippi and Texas.

In contrast, the median coverage levels for diphtheria, tetanus toxoid, and acellular pertussis; poliovirus; and hepatitis B vaccines all were at or above the Healthy People 2020 target of 95%.

The findings were collected from data reported at the start of the school year by health department or school personnel, which are then reported by local health authorities to the CDC.

"Although median MMR vaccination coverage among children entering kindergarten was close to the ≥95% target," Dr. Greby and colleagues write, "MMR vaccination coverage and exemptions aggregated at national or state levels can mask substantial vulnerability at the local level."

According to the CDC, there might be "smaller areas and schools where low levels of immunization could sustain ongoing measles transmission after importation from other countries."

The researchers note that a limitation of the analysis is that reports might not be updated as a child obtains the required vaccines or exemptions later in the school year. In addition, "vaccines required and survey methods varied by state, although efforts to improve standardization are in progress."

The authors have disclosed no relevant financial relationships.

Morb Mortal Wkly Rep. 2012;61:647-652. Full text


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