Median coverage neared 95% for vaccines required for kindergarten entry, with some notable increases in MMR coverage versus a year ago, CDC researchers found.

Estimates for median coverage for measles, mumps, and rubella vaccine (MMR), diphtheria tetanus and acellular pertussis vaccine (DTaP), and varicella vaccine were all just under 95% during the 2015-2016 school year, reported Ranee Seither, MPH, of the CDC, and colleagues, writing in the Morbidity and Mortality Weekly Report.

Overall, 32 states reported an increase in MMR coverage compared with the 2014-2015 school year. A total of 22 states reported MMR coverage at or above 95%. Among states reporting vaccination coverage data in both years, five more states reported ≥95% median coverage than in the prior year, with a median increase of 0.7 percentage points (ranging from a 0.1 percentage point increase in Wyoming to a 4.1 percentage point increase in Oklahoma). Three states and Washington D.C. reported coverage below a median of 90%, but this was four fewer states than last year.

Not surprisingly, the authors said this may be due to the 2015 measles outbreaks, which included 159 persons from 18 states -- 80% of whom were unvaccinated or whose vaccination status was unknown.



Regarding coverage rates by state, Colorado had the lowest median coverage for MMR, DTaP, and varicella (ranging from 85.7% to 87.1%), while Maryland had the highest rates for MMR and DTaP, and Mississippi for varicella (all exceeding 99%). For the first time, certain states reported data on students entering school during a "grace period," where students are allowed to attend school before being required to provide documentation of vaccination or after being granted "provisional enrollment" (which allows students to complete a catch-up vaccination schedule); 45 states and Washington D.C. allow these options.

A total of 23 states reported these data, with a median 2.0% of students fitting either one of the descriptions. These ranged from 0.0% in Wyoming to 5.4% of kindergarteners in New Hampshire. Notably, 12 of 23 states reported that the percentage of children was higher than the percentage claiming one or more vaccine exemptions.

Among the 47 states and Washington D.C. that reported exemption data, the percentage of children claiming at least one vaccination exemption was similar (1.9%); and while nine states had at least 4% of kindergarteners claiming any exemption, this was down from 11 states a year ago.

Vaccination Rates Remain High, Stable for Younger Children
In a separate study, median vaccine coverage for children ages 19 to 35 months remained over 90% for the poliovirus vaccine, the Hepatitis B vaccine, and the MMR and varicella vaccines, reported Holly A. Hill, MD, of the CDC and colleagues.

According to 2015 National Immunization Survey data, uptake of these vaccines in young children met the Healthy People 2020 targets as follows:
3 doses of poliovirus vaccine: 93.7%;
3 doses Hepatitis B vaccine: 92.6%;
1 dose MMR: 91.9%; and
1 dose varicella: 91.8%.
However, coverage remained below the 90% target for:
4 doses of DTaP: 84.6%;
Full series of Haemophilus influenzae type B: 82.7%; and
4 doses of the pneumococcal conjugate vaccine: 84.1%.

There were stark gaps in vaccination coverage by poverty status, the researchers found, with notable differences among children living below the federal poverty level compared with those at or above the level. The largest differences were observed for rotavirus vaccine (66.8% versus 76.8%, respectively), ≥4 doses of the pneumococcal conjugate vaccine (78.9% versus 87.2%), and the full series of the Haemophilus influenzae type b vaccine (78.1% versus 85.5%). The authors estimated that a little under a third of children ages 19 to 35 months live below the federal poverty level.

The percentage of children receiving no vaccinations in this age group remained at less than 1%.