Vaccine Coverage in Young Children Holding Steady

Exemptions Ticked Up Slightly, However

November 06, 2019 10:14 am News Staff –Two Morbidity and Mortality Weekly Reports issued Oct. 18 offer a snapshot of vaccination coverage among young children in the United States. 

The 2018-19 school year figures hew closely to the previous year's coverage percentages -- 94.3%, 95.1% and 93.8%, respectively -- for the same three vaccines.

The latest percentages reflect school-reported data on coverage rates in 49 states and the District of Columbia (Alaska did not report). Other findings presented in the MMWR were based on vaccine exemption data from 50 states and provisional enrollment and grace period status data from 30 states.

Notably, although 2.5% of kindergartners had an exemption (0.3% medical; 2.2% nonmedical) from at least one state-required vaccine (not limited to MMR, DTaP and varicella vaccines) -- up from 2.3% during the 2017-18 school year -- 2.8% of these children were not up to date on their MMR vaccine doses but did not have an exemption.

Finally, 2% of kindergartners were listed as attending school within a grace period or were provisionally enrolled among the 30 states that reported this data. In one-third of these states, the percentage of children counted as provisionally enrolled or within a grace period exceeded that of children with exemptions from one or more vaccines. According to the researchers, 44 states could potentially achieve or exceed the 95% MMR coverage threshold if all nonexempt kindergartners, many of whom are provisionally enrolled or within a grace period, were vaccinated.

The MMWR cautioned that vaccination assessments varied across immunization programs because of state-to-state differences in required vaccines and doses, the number of vaccines assessed, methods used, and data reported.

A second MMWR published the same day similarly found that vaccine coverage among children born in 2015 and 2016 has remained high and relatively steady for most of the vaccine doses the ACIP recommends children receive by age 24 months to prevent 14 potentially serious illnesses.

Using data from the National Immunization Survey-Child, CDC researchers examined coverage with the recommended number of doses of each vaccine at the national, state, territorial and -- in some cases -- local levels.

The researchers found that nationally, vaccination coverage in this population was 90% or greater for three or more doses of poliovirus vaccine, at least one dose of MMR vaccine, three or more doses of hepatitis B vaccine, and at least one dose of varicella vaccine. This was despite the fact that in 20 states, MMR vaccine coverage dipped below 90%.

Also noteworthy was a finding that, at only 56.6% coverage, children included in this survey were least likely to be up to date with two or more doses of seasonal influenza vaccine. Even so, compared with the 2013-14 birth cohort, this level of coverage represented the largest gain -- an increase of 3.6 percentage points -- seen among any of the vaccines assessed. Second was a rise of 3.2 percentage points in the Hep B vaccine birth dose, followed by a 2.6 percentage point bump in coverage with two or more doses of Hep A vaccine, compared with the 2013-14 group.

Overall, only slightly more than 1% of children born in 2015 or 2016 had received no vaccines at all by their second birthday.

Regarding disparities in coverage, children who were uninsured and those who were covered by Medicaid or other nonprivate insurance had lower coverage than did children covered by private insurance for all the vaccines assessed. Compared with privately insured children, children who were uninsured had coverage gaps that ranged from 7.8 percentage points for the Hep B birth dose to 33.8 percentage points for two or more doses of flu vaccine.

Race/ethnicity, income level and geographical location also appeared to contribute to vaccine coverage gaps, but these disparities tended to be smaller than those associated with insurance status.

Taken together, the two reports indicate a need to boost access to vaccines, particularly for certain at-risk populations, such as children who are uninsured or who are insured by Medicaid or other nonprivate insurance, children living below the poverty level, and those living in rural areas.

"Improvements in childhood vaccination coverage will require that parents and other caregivers have access to vaccination providers and believe in the safety and effectiveness of vaccines," one of the reports noted.

"Compelling and accessible educational materials, combined with effective techniques for providers to use when discussing vaccination, can be used to counter inaccurate claims and communicate the value of vaccines in protecting the health of children."