The states with the best—and worst—vaccine coverage Colorado, Arkansas kindergarteners have lowest vaccination rates in the country

A CDC report this month detailed state-by-state child vaccination rates for kindergarteners who began school in fall 2012, and the findings suggest the need for vaccine campaigns in communities where exemptions are exceptionally frequent.

Overall vaccination rates near CDC goal

94.5% of kindergarteners received the vaccine for measles, mumps, and rubella (MMR);

95.1% received the vaccine for acellular pertussis (DTaP); and

93.8% received the vaccine for varicella, or chickenpox.

For the report, CDC researchers studied data from the agency's federally funded vaccination programs, which span all 50 states and the District of Columbia. Overall, the report found that:

The federal government's target vaccination rate for the three conditions is 95% of U.S. kindergarteners.

Which states have the highest vaccination rates

Mississippi had the highest vaccination rates for all three conditions, with 99.9% of children receiving the MMR, DTaP, and varicella vaccines.

Broken down by vaccine, the states with the best MMR vaccine rates were:

1. Mississippi (99.9%);

2. Maryland (98.2%);

3. South Dakota (97.9%);

4. Texas (97.5%); and

5. Wyoming (97.5%).

Which states have the lowest vaccination rates

Meanwhile, the study found that Colorado and Arkansas had the lowest vaccination rates for the conditions. Specifically, the states with lowest MMR vaccination rates were:

1. Colorado (85.7%);

2. Arkansas (85.9%);

3. Pennsylvania (87%);

4. Idaho (89%); and

5. North Dakota (89.9%).

Colorado had the lowest vaccination rate for varicella, with just 84.6% of kindergarteners receiving the recommended doses, and Arkansas had the lowest vaccination rate for DTaP, with just 82.9% receiving the vaccine.

"High vaccination coverage levels at the national and state levels might mask clustering of unvaccinated children at local levels where vaccine-preventable diseases might be transmitted," CDC researchers wrote, adding that health departments and schools can use the data "to identify schools with low vaccination coverage and high exemption levels" (CDC report, 8/2; Babay, Philadelphia Inquirer, 8/6; Jaslow, CBS News, 8/1).