More parents across the country are choosing not to vaccinate their children, according to recent studies.

Alleged links between some vaccines and autism may have begun the trend, experts say. And as many diseases have faded from modern society, doctors say parents now don't realize the risks associated with skipping out on shots for their children.

Hall County, however, is so far not following the trend.

"We are not seeing a big drop-off in immunizations here," said Dr. David Westfall, public health director for District 2. "We do have some people that are asking for exemptions, but for the most part here in Hall County we have a very good immunization rates, one of the best in the state."

He said a 2005 study by the Division of Public Health epidemiology branch showed the north district, based in Gainesville, had 98 percent of all 2-year-olds fully immunized.

Westfall attributed the high vaccination rate to the area's medical community and public health staff, which he said provide a safety net for those who need care.

In other states, the vaccination rate is not nearly as high.

An Associated Press analysis found that in eight states, more than 1 in 20 public school kindergartners do not get the vaccines required for attendance.

States with the highest exemption rates are in the West and upper Midwest, and in some areas in northeast Washington, vaccination exemption rates have recently been as high as 50 percent, the analysis found.

Associated Press looked at kindergarten exemption rates for 2006 to 2007 and 2010 to 2011. Alaska had the highest exemption rate of 9 percent and Mississippi was lowest, almost at zero.

In Georgia, parents have two options to opt out of school vaccines. They can get either a medical or religious exemption, said Mamie Coker, health services coordinator for Hall County Schools. Medical exemptions are only valid for one year but religious ones last the whole time a child is in school.

"The parent must write a statement that immunizations conflict with their religious beliefs," she said. "They have to have that statement notarized because it's a sworn affidavit. We probably on average have less than a handful at each school."

Coker said another option, specifically for chickenpox, was for children to have blood work done to show they are already immune to the disease.

Dr. Eugene Cindea, chairman of the pediatric department at The Longstreet Clinic in Gainesville, said there were more exemptions now than 20 years ago, but short term not that many.

"We have less (vaccine exemptions) than we did before, even in the last six to nine months," Cindea said. "And in fact, some children who were not vaccinated have started to become vaccinated, including some children with autistic disorders. We've had several mothers continue or restart their vaccinations and that is exciting."

He said the big issue with any vaccine, especially new ones parents aren't as familiar with, is education.

"When you educate parents and patients with the correct information, they commonly make the correct choice," Cindea said. "If you're not informed, it's frightening."

Why some parents worry

Coker said anti-vaccine trend probably started in the 1990s when concerns rose about autism being linked to the mumps, measles and rubella vaccine.

"The symptoms developed around the same time they were getting the MMR vaccine," she said.

And even though studies have disproved the autism and MMR link, concerns have waned little. Westfall said the prevalence of social media and the Internet help small pockets of parents spread their concern to others, one reason why the trend could be growing.

"There has been some skepticism, cynicism and distrust of the scientific community that maybe some of the studies ... are slanted toward the economic benefit of pharmaceutical companies or certain researchers," he said.

Health care officials said parents raise other concerns, as well, though.

"No. 1, they don't like the numerous amounts their children have to get at once," Coker said. "Some parents want to spread them out on an alternate schedule."

She said some local physicians are willing to work with parents on the issue and give school systems immunization certificates that expire when the child needs to get his next shot.

Westfall said the trend has a lot to do with vaccines being victims of their own success.

"We now have a generation of people who have grown up without seeing vaccine-preventable illnesses because vaccines have been very effective over the last generation," Westfall said. "There were a number of children who died each year. Most people now have grown up in an environment where those diseases are very rare and their perception of them as significant is probably tainted by that. They don't realize these are serious illnesses."

The issue is also political.

"It's maybe somewhat related to the polarization of beliefs we're seeing politically right now with people arguing vehemently of the role of government in making decisions for them. Some people see the requirements to have vaccines as an invasion of their privacy, of their right to make choices. ... We're seeing pushback from folks that say all choices related to health, medicine and child-rearing should be theirs and theirs alone."

Why vaccines are required

Even with the risk of a mild infection, health care officials say vaccines for preventable childhood diseases are vital, both for protecting individuals and the entire population.

"People who have immune system disorders, who are on chemotherapy or have other serious illnesses, if the population as a whole is not vaccinated and that disease is in the community, these vulnerable people have no protection and get the illness with very severe consequences," Westfall said.

School health officials are in charge of reporting diseases they see.

And some diseases are on the rise, even in vaccinated populations.

Pertussis, or whooping cough, now requires an adult booster shot, Coker said. The childhood vaccine waned by the time a child was through with elementary school. She said it is an issue now for pregnant teachers and for teen parents, who might expose their children to the disease.

"We have forgotten what preventable childhood illnesses can cause," Coker said. "Polio used to cripple children.

You can get meningitis and get seriously ill from just chickenpox. That's why parents should not go and purposely expose their children to chickenpox to avoid getting the vaccine. Even with pertussis, some states are having issues with numerous cases. It's not something you want to experience."

Cindea said most cases of vaccine-preventable diseases, such as chickenpox and measles, occur in individuals who have not been vaccinated at all or who have not had the full dose of a vaccine or a booster shot.

"When you look back in the data, in the pre-vaccine years, there were serious complications and a number of deaths from the vaccine-preventable illnesses," Westfall said.

Before the availability of the chickenpox vaccine, he said there were on average 10,000 hospitalizations and 43 deaths associated with the disease each year.

And those trends might return if fewer children are vaccinated.

From 1997 to 2000, Westfall said there were 30,000 cases of pertussis and 62 deaths reported.

"As we see people either trying to avoid vaccination or delaying vaccination, we are seeing a reappearance of some of these diseases," Westfall said. "Fortunately because most people have gotten immunizations, we don't see measles very frequently, but worldwide it kills 500,000 children a year."

In 2010, California had more than 2,100 cases of whooping cough, which resulted in 10 infant deaths. Only one had received a first dose of the vaccine, according to the Associated Press analysis.

And according to the Centers for Disease Control and Prevention, from Jan. 1 to June 17, more measles cases were reported in the United States compared with that same period since 1996.

The diseases though now rare, can still be spread, especially due to people traveling to and from other countries.

"We are 60 miles away from the world's busiest airport," Cindea said. "We're 60 miles away from every disease in the world. That's a sobering thought."