As a baby, Benjamin Ransom was ever-smiling and giggling. The photographer at Sears didn't even have to joke with him to get him to grin for a family photo, recalls his father, Jeff Ransom, of Fort Oglethorpe.
But soon after he reached 15 months, Benjamin seemed to change into a different child. He ceased smiling and avoided eye contact. His speech reverted from clear words into baby babble, and finally he stopped talking altogether, Mr. Ransom said.
"He just had a blank stare on his face," he said.
After a year of failed speech therapy, Benjamin -- who is now 10 -- was diagnosed with autism spectrum disorder, an increasingly common diagnosis characterized by a difficulty in verbal and nonverbal communication and social interactions. Severity can range from very mild to debilitating.
But despite medical evidence to the contrary, Mr. Ransom is convinced that a series of recommended vaccines his son received at 15 months -- including protection against measles, mumps and rubella, and Hib meningitis -- prompted the sudden change in his son, who stopped talking in the weeks following his vaccination.
"You're not going to convince me vaccines did not change my child," Mr. Ransom said. "I saw it."
EARLY SIGNS OF AUTISM
* Lack or delay in spoken language
* Repetitive use of language and/or motor mannerisms, e.g., hand-flapping, twirling objects
* Little or no eye contact
* Lack of interest in peer relationships
* Lack of spontaneous or make-believe play
* Persistent fixation on parts of objects
Source: Autism Society of America
* Team Centers: 423-622-0500
* Siskin Children's Institute: 423-648-1700, siskin.org
* Autism Society of Middle Tennessee: 615-385-2077
* Orange Grove Center: 423-629-1451
Those who maintain there is a link between vaccines and autism often cite research by Dr. Mark Geier and his son David. But the Institute of Medicine has said those studies were flawed.
The Geiers, who spoke in Chattanooga last year at an event organized by the Complementary Health Education Organizations, have done a number of studies analyzing data in the Vaccine Adverse Event Reporting System, maintained by the U.S. Centers for Disease Control and Prevention. They claimed to have found a higher risk for complaints related to autism among children who received a thimserosal-containing vaccine.
The Institute of Medicine, which analyzed research on the issue, wrote that the Geier studies have "serious methodological flaws and their analytic methods were nontransparent, making their results uninterpretable." The American Academy of Pediatrics, in its critique of a 2003 Geier study, has said that reliance on this reporting system, in which most complaints are voluntary and reporting is inconsistent, is invalid.
The debate over the connection between autism and vaccines, particularly those that contain thimerosal -- a preservative that contains mercury -- has been fueled by the alarming rise in the number of children diagnosed with the condition and the proliferation of Web sites, often led by advocacy groups for parents of children with autism, that argue vaccines cause autism, experts say.
About one in every 110 children now has a form of autism spectrum disorder, according to the most recent estimates from the U.S. Centers for Disease Control and Prevention.
Experts are struggling to tamp down fears they say are without scientific basis. They point out that symptoms of autism tend to emerge in the second year of life, regardless of vaccine status.
Physicians also worry that parents refusing to vaccinate their children are opening the door to a resurgence of diseases, from polio to whooping cough, that had been virtually wiped out by the country's robust vaccination program.
Outbreaks of measles and pertussis, or whooping cough, and Hib meningitis have been linked to parents refusing or delaying vaccination of their children, experts say.
"We definitely see the consequences of choosing not to vaccinate. That's why we take it so seriously," said Dr. Kelly Moore, medical director of the immunization program with the Tennessee Department of Health.
NEED FOR EXPLANATION
The vaccine-autism controversy has been brewing for years. This fall, the U.S. Supreme Court will take up a case to determine whether vaccine manufacturers can be sued by parents who allege their children were harmed by vaccines, The Associated Press reported. Frequently these kinds of cases involve autism, according to the AP.
A special federal court ruled Friday that thimerosal is not to blame for autism, the AP reported.
The court concluded the Oregon-based parents who filed the suit had failed to show a connection between the preservative and their son's autism. The ruling came in a special branch of the U.S. Court of Federal Claims established to handle claims of injury from vaccines.
For almost a decade, all recommended routine vaccines in the U.S., except some influenza shots, have been free of thimerosal.
A study largely seen as the launch pad for fears over the vaccine-autism connection -- published in 1998 in the British medical journal Lancet -- was retracted last month for being flawed. The study's author claimed that leakage of the measles disease from the measles-mumps-rubella vaccines, which became standard in the mid-1980s, could cause autism. The MMR vaccine has never contained thimerosal.
The vaccine-autism theory has taken such a deep hold in part because of the human desire to understand, said Dr. Leslie Rubin, pediatric developmental specialist with Team Centers, a private, nonprofit agency in Chattanooga serving people with developmental disabilities.
Even before the MMR vaccine became standard in the mid-'80s, Dr. Rubin said he regularly met with parents searching answers for their child's sudden onset of autism symptoms around 18 months of age, a "classic" pattern in autism.
Parents would say that they had recently moved or had another baby as a possible explanation for their child's condition, he recalled.
"We as human beings need explanations," he said. "You can see how you can link it with something real, something tangible."
Despite the broad medical consensus that no credible scientific evidence has linked vaccines and autism, a significant number of parents are harboring fear and distrust of vaccines.
About 11 percent of parents surveyed in 2009 said they had declined to give their child or children at least one recommended vaccine, according to the study published in the March 1 edition of the journal Pediatrics.
Local doctors say they are encountering parents who are refusing or delaying recommended vaccinations for their children.
Chattanooga pediatrician Dr. Peter Rawlings said he has had to stop seeing some patients whose parents refuse to get them vaccinated because he doesn't feel comfortable being complicit with what he feels could be termed child neglect.
These parents are counting on the immunity of the general population that has been vaccinated to protect their children from these dangerous illnesses, he said.
"That's literally what a lot of these families are banking on, that there's enough herd immunity that they don't have to give it to their child," he said.
But as more parents decide to forgo recommended vaccines that herd immunity breaks down, he said. Immune-compromised children who can't be vaccinated -- such as children with leukemia -- are then at greater risk of contracting a disease such as measles which, especially for them, could be deadly, experts say.
"Science is all over Internet"
Health officials emphasize that a litany of scientific data has found no causal link between autism and vaccines. In 2004, an Institute of Medicine committee released a report with that conclusion, citing five large epidemiological studies -- in the United States, United Kingdom, Denmark and Sweden since 2001 -- that found no association between vaccines containing thimerosal or the MMR vaccine and autism.
But some advocacy groups maintain that public health officials are conspiring to gloss over valid scientific evidence of real links between vaccines and autism, pointing to research compiled by advocacy groups and online publications such as Age of Autism and the Coalition for Safe Minds, which have helped unite a network of parents in an anti-vaccine campaign.
"The science is all over the Internet. It's just you're not getting it through the health department," said Tami Freedman, a board member of the Chattanooga chapter of the Complementary Health Education Organization, a nonprofit focused on natural health care as a means to improve health.
Dr. Moore said part of the reason the fear of vaccines has taken such a hold is the proliferation of information on the Internet that can fuel a parent's search for answers to a highly mysterious condition.
"There is no filter on the Internet. Anyone can post anything," she said. "The concern that I have is that people can make well-informed decisions and you make that by knowing the facts and not just the rumors."
Experts attribute the rise in diagnoses of autism at least in part to a broad expansion of the definition of autism to include individuals who might otherwise have been diagnosed with another condition such as Down syndrome. On the other end of the spectrum, those with Asperger's syndrome, a type of autism spectrum disorder, in the past may have been considered just eccentric.
Dr. Rubin said there is also an urgent need for research that explores the effect of environmental toxins that have become pervasive since the Industrial Revolution.
For example, prenatal exposure to phthalates, which can be found in perfumes, make-up and nail polish, has been associated with behavioral and attention problems in children, according to a study published this year in Environmental Health Perspectives.
"Here is where the truth may lie," Dr. Rubin said. "That's where we can all lobby the government to say, 'You know what? There are a lot of toxins causing harm to ourselves, our children, unborn babies, to the future of mankind, and we've got to begin to understand what these toxins can do.' That's where I'm fully into support of these kinds of advocacy groups."
Mr. Ransom's son Ben now istalking and enrolled in mainstream public school classes, but he still requires speech and occupational therapy, his father said. Mr. Ransom said he will never stop believing vaccines changed his child.
"I went into a pediatrician's office, and I held my child down and let them give him a brain injury," Mr. Ransom said.
Dr. Moore said she wants to emphasize to parents that they don't need to feel culpable for their child's autism.
"It is a very difficult situation, and I think what makes me most sad is that the parents believe this is something they did by letting their child be vaccinated. ... There's no reason to feel that kind of guilt because it wasn't something that they did," she said.