Tennessee has the highest immunization rate among young children out of all 50 states, according to an annual ranking of health measures.

About 94 percent of children between 19 months and 35 months get recommended immunizations, more than any other state, according to "America's Health Rankings," released Tuesday.

"That's a very impressive statistic," said Dr. Mark Anderson, Chattanooga infectious disease specialist. "There are outbreaks now periodically of measles, mumps and whooping cough, which is a really scary one. ... If infants get exposed before they get their first immunization, it can be fatal."

In overall health rankings, the Volunteer State moved up in the rankings to 42nd place, compared to 44th last year and 48th in 2008.

The national rankings, based on United Health Foundation's annual survey of government and academic data sources, cover health factors ranging from poverty levels to smoking rates to cancer deaths.

United Health Foundation, a nonprofit private foundation, is backed by insurance company United Health Group.

Georgia had the biggest gain of any state this year, improving seven spots to reach 36th place, compared to 43rd last year.

But Georgia's health outcomes are still disappointing, and its ranking is still relatively poor, said Ali Donahue, marketing director for northwest Georgia Healthcare Partnership, a nonprofit focused on improving health.

"We're still along with Tennessee in the bottom third," she said. "We've maybe caught a little bit of a break, but we still have a lot we need to focus on."

Georgia ranked 45th for high school graduation rates and ranked 47th for incidence of infectious diseases, with 24.5 cases per 100,000 population, according to the report.

Obesity remains a persistent challenge in Tennessee, where 32.8 percent of the adult population is obese, the report said.

But this year, Tennessee saw improvements in the majority of health determinants, including smoking rates and preventable hospitalizations, said Tennessee Health Commissioner Susan Cooper, during a Washington, D.C.-based webcast announcing the report.

Cooper attributed the improvement to health officials' efforts to change behaviors by encouraging daily exercise, healthy eating and smoking cessation and prevention.

State policies now require nutritional standards for foods sold in school vending machines and bake sales, and require children to get at least 90 minutes of physical activity each week, she said.

"We are one of 19 states with nutritional standards for school meals and snacks that are more strict than the USDA standards," she said. "Policy interventions at all levels provide a 'stickiness factor' -- once implemented, they are hardest to reverse."

In Georgia, a ban on smoking in most public places passed in 2005 and has finally helped lower the tobacco use rate, which is down to 17.6 percent, compared to 19.5 percent in 2009, Donahue said. She thinks progress on obesity rates and other health measures will be similarly slow.

"There are not a lot of solid programs out there yet. It's been a lot of education dissemination. [But] we know we're unhealthy. We need to see some action," she said.