In more encouraging public health news, the Centers for Disease Control and Prevention reports that vaccination rates among kindergarteners have remained stable, with the median vaccine exemption rate at 2 percent. Some states even reported an increase in immunization rates.

In a study published last week in CDC’s Morbidity and Mortality Weekly Report, researchers examined 2016-2017 data from 49 states regarding coverage of three vaccines: measles, mumps and rubella (MMR); diphtheria, tetanus and acellular pertussis (DTaP); and varicella, more commonly known as chickenpox. Researchers also examined exemption numbers from all 50 states as well as data on kindergartners in 27 states who were provisionally enrolled in school or were within a vaccine grace period. They found median vaccination coverage was at 94.5 percent for state-required doses of DTaP; at 94 percent for two doses of MMR, which is what the Advisory Committee on Immunization Practices recommends; and at 93.8 percent for two doses of varicella, also what the committee recommends.

Overall, it means rates of vaccine coverage and vaccine exemption have been “relatively consistent” since 2011-2012. According to researchers: “Vaccination coverage remains consistently high and exemptions low at state and national levels.”

Getting into the particulars, the study reported that MMR vaccine coverage ranged from more than 85 percent in Washington, D.C., to more than 99 percent in Mississippi, with 20 states reporting coverage at 95 percent or higher. Among the 48 states that reported DTaP data, coverage ranged from about 82 percent in Washington, D.C., to nearly 100 percent in Maryland, with 23 states at 95 percent or higher. On chickenpox, 42 states reported coverage ranging from more than 84 percent in D.C. to more than 99 percent in Mississippi, with 15 states reporting coverage rates of 95 percent or above.

Among 46 states reporting data, the median percentage of kindergartners exempted from one or more vaccines was 2 percent. That rate ranged from less than 1 percent in Mississippi to nearly 7 percent in Alaska. Exemption rates were lower than 1 percent in four states: Alabama, Louisiana, Mississippi and West Virginia. Between the 2015-2016 and 2016-2017 school years, the exemption rate decreased in California and Vermont and slightly increased in Alaska, Georgia, Nevada, New Hampshire, New Mexico, North Carolina and Wisconsin. The median percentage of kindergartners in school with a provisional enrollment or during a grace period was at 2 percent.

The study found that four states — California, New York, North Dakota and Tennessee — reported increased coverage rates for all three vaccines. Researchers said the increases could be due to policy changes as well as efforts to educate school personnel on vaccine requirements. For example, California eliminated nonmedical exemptions for kindergartners at public and private schools. And in North Dakota, educating school superintendents on the importance of vaccines prompted most school districts to more strictly enforce vaccine requirements, which led to coverage increases of more than 3 percentage points for each of the three vaccines.

Researchers concluded the study by pointing to the importance of local data in guiding public health immunization efforts. Co-authors Ranee Seither, Kayla Calhoun, Erica Street, Jenelle Mellerson, Cynthia Knighton, Ashley Tippins and J. Michael Underwood write:

However, clusters of low vaccination coverage continue to serve as opportunities for outbreaks of vaccine-preventable diseases. Because vaccination coverage and exemption levels are clustered locally, availability of local-level vaccination data can help immunization programs identify schools that might be vulnerable in an outbreak. CDC is working with programs to improve collection and use of grace period and provisional enrollment data to understand contributing factors for reported under-vaccination and identify programmatic actions that might increase vaccination coverage among kindergartners.

Proposals at the federal level could impact vaccine rates as well. For example, lawmakers are looking to raid billions from the Affordable Care Act’s Prevention and Public Health Fund (PPHF) to keep the Children’s Health Insurance Program running — leaders in Congress let funds for the vital safety net program expire in September. However, monies from the PPHF already go to support other essential health programs, such as CDC’s Section 317 Immunization Program, which provides vaccines to underinsured children and uninsured adults. Fifty-three percent of the 317 funding now comes from the PPHF.

Advocates are calling on Congress to pass a “clean” bill that extends CHIP funding without pitting critical health programs against each other.

For a copy of the new vaccine study, visit MMWR.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for 15 years. Follow me on Twitter — @kkrisberg.