March 6, 2008 -- Federal officials say a Georgia girl is entitled to compensation from a federal vaccine injury fund because she developed autism-like symptoms after receiving childhood vaccines in 2000.
Hannah's father, Jon, tells WebMD he was not surprised by the compensation decision.
"When you are talking about the courtroom versus science, the burden of proof is different," Poling says. "(But) we showed there was a plausible mechanism. We showed that an injury occurred shortly after her vaccination. Her growth curve went flat for months."
The government has not said that childhood vaccines cause autism; rather, officials conclude that the vaccines given to the girl in 2000 aggravated a pre-existing condition -- a mitochondrial disorder -- that then manifested as a regressive neurological disease with some symptoms of autism spectrum disorder.
Those who believe there is a vaccine-autism link call the decision a victory, but those who see no link worry that parents will once again shy away from childhood vaccines.
"Nothing of this situation should be generalized to the risk of vaccines for normal children," CDC Director Julie Gerberding, MD, said at a news conference. "None of this is going to change any of our recommendations stating the importance of vaccination for every child."
(Are you changing your child's vaccine schedule because of autism fears? Tell us what you're thinking on WebMD's Autism Support Group message board.)
The Back Story
Autism and autism spectrum disorders begin before the age of 3, according to the CDC, and include a group of developmental disabilities marked by great difficulty in social interaction and communication. Difficulties on the spectrum range from mild to severe.
The disorder is on the rise, with one in 150 children now diagnosed with autism spectrum disorders, according to the CDC.
Suspicion of a vaccine link with autism has been ongoing at numerous advocacy groups, who believe that thimerosal, a mercury-containing preservative used in some vaccines, is to blame. There is increasing concern and an increasing awareness of the theoretical potential for neurotoxicity. The preservative, used in vaccines since the 1930s, has been removed or reduced to trace amounts in all vaccines recommended for children 6 years of age or younger, with the exception of inactivated flu vaccine. A preservative-free version of the inactivated flu vaccine is available.
Advocacy groups against childhood vaccines take issue with other vaccine components as well.
Autism Groups: Decision a Victory
Sallie Bernard, co-founder of SafeMinds (Sensible Action for Ending Mercury-Induced Neurological Disorders), is ecstatic about the decision. "We're finally seeing the truth come out," she tells WebMD. "We've gotten such incredible pushback, yet here is a case showing this connection quite clearly.
"Here is a case that really looked into the science, and behind this child's case of autism, they have found a link between the child's autism and the vaccines that she was given," she says.
Bernard says she hopes the decision will spur re-investigation of the issue. "I think this will push more scientists and hopefully the NIH [National Institutes of Health] to really investigate the role of vaccines, the role of mercury, in autism, because this case is so compelling."
Autism Expert: Case Is "Rare"
A pediatrician who serves on a childhood vaccine advisory committee for the U.S. Department of Health and Human Services sees the case differently. "To say mercury causes autism is a giant leap," says Jaime Deville, MD, a pediatrician at Mattel Children's Hospital at the University of California Los Angeles.
"Epidemiological studies do not support the hypothesis that mercury in vaccines causes autism in the general population,'' he tells WebMD. "However, there might be individual sporadic, or rare cases in which patients have an adverse reaction after a dose of a vaccine that might exacerbate a pre-existing condition."
That was the contention in Hannah's case -- that Hannah developed a disorder of the mitochondria, the cells' "power sources," before developing autism-like symptoms.
In a statement, Chuck Mohan, executive director and CEO of the United Mitochondrial Disease Foundation, says science has not linked vaccines to mitochondrial disorders.
"There are no scientific studies documenting that childhood vaccinations cause or worsen mitochondrial diseases, but there is very little scientific research in this area," the statement reads. "Mitochondrial diseases are as prevalent as childhood leukemia, however the National Institutes of Health devotes only $11 million a year to research into mitochondrial disorders and only about one-third of that is earmarked for primary mitochondrial disease research. Many scientists believe unmasking the causes of mitochondrial disease may lead to possible cures for Parkinson's, Alzheimer's, heart disease and cancer."
Deville worries that parents will again shy away from vaccines. "I would expect parents to start calling pediatricians," he tells WebMD. But he adds that Hannah's situation "seems to be an isolated case."
He also points out: "Once mercury was removed [from most childhood vaccines] in 2001, autism cases did not decline."
He doubts that the decision will spur further research into the proposed vaccine-autism link, partly because of a lack of research funding.
Autism-Vaccine Link: Hannah's Story
According to the government concession in the Poling case, Hannah had met her "developmental milestones" such as crawling and walking on schedule during her first 18 months. But two days after receiving nine childhood vaccines (five shots) in July 2000, she developed a 102.3-degree fever and became irritable and lethargic. The symptoms continued and worsened over the next few months.
By the fall of 2000, the parents became worried about her language development and had her assessed. The health care professional examining her concluded there were deficits in communication and social development.
By February, 2001, doctors examining Hannah found that she had a persistent loss of previously acquired language, lacked eye contact, and did not relate well to others. She persistently screamed and arched her back. Doctors concluded that she was developmentally delayed and had features of autism spectrum disorder.
Later in 2001, doctors found a defect in "cellular energetics" and diagnosed a disorder of the mitochrondria.
Her father, Jon, then a neurologist at Johns Hopkins Hospital in Baltimore, co-authored a paper describing how autistic spectrum disorders can be associated with mitochondrial dysfunction. It was published in 2006 in the Journal of Child Neurology.
Accepting his daughter's diagnosis was difficult, Poling tells WebMD. He says the family was in denial initially that anything was seriously wrong. "After six months of essentially our daughter being a zombie and gone, we knew this wasn't going away," he says. "This was chronic. And we had to come to grips with that."
Still, Poling says his daughter's experience has not turned him against vaccines; he just wants any vaccination risks to be acknowledged and addressed.
"I want to make it clear I am not anti-vaccine," he says. "Vaccines are one of the most important, if not the most important advance, in medicine in at least the past 100 years. But I don't think that vaccines should enjoy a sacred cow status, where if you attack them you are out of mainline medicine.
"Every treatment has a risk and a benefit," he says. "To say there are no risks to any treatment is not true.
"I don't think the case should scare people," Poling adds. "Sometimes people are injured by a vaccine, but they are safe for the majority of people. I could say that with a clean conscience. But I couldn't say that vaccines are absolutely safe, that they are not linked to brain injury and they are not linked to autism."
Poling hopes the fed's decision will trigger government action. "I hope it will force government agencies to look further into what susceptibility factors are out there for children to develop brain injury after vaccination, to look into the susceptibility factors of people at risk."
His advice for parents? They should demand to know a vaccine's safety record before agreeing to give it to their child, including any known links with metabolic disorders and susceptibility to injury, he says.
Hannah Poling suffered from a form of mitochondrial disease caused by a genetic defect in her mitochondrial DNA.
Mitochondria are organelles -- tiny bodies within our cells -- that carry their own DNA, which we inherit from our mothers. Mitochondria provide the energy cells need to function.
Edwin Trevathan, MD, MPH, director of the CDC's National Center on Birth Defects and Developmental Disabilities, said at the news conference that when children with mitochondrial disorders are placed under severe stress, such as a high fever, their bodies don't make enough energy. This often damages the brain, the body organ that needs the most energy.
The type of problem such children develop depends on the part of the brain that is affected. Some may become spastic and have trouble walking. Others may have seizures, problems with language, and sometimes problems with social behavior, Trevathan said.
Children who have mitochondrial disorders, even though they seem normal, are predestined to have a problem when they have stress," he said at the CDC news conference. "This is distressing for parents who watch their children suddenly deteriorate. Most are normal appearing until they exhibit signs of disease when placed under severe stress. Most do not have problems with autism."
Some researchers have suggested that mitochondrial diseases or disorders are more common in children with autism than in other children.
"If anyone said mitochondrial disease prevalence is higher among children with autism, that is a hypothesis and there is remarkably little data to support it," Trevathan said. "The truth is we don't know the prevalence of mitochondrial disease in the general population."
Mohan of the United Mitochondrial Disease Foundation tells WebMD that mitochondrial disease affects one in 4,000 children -- and maybe more. But he rejects the link to autism.
"Persons with mitochondrial disease don't necessarily have autism, and persons with autism don't necessarily have mitochondrial disease," Mohan says. "Just as with vaccines, there is no scientific proof vaccinations cause mitochondrial deficiencies or autism."
Trevathan notes that though doctors are urged to consider each child's individual risk, vaccinations are generally recommended for children with mitochondrial disorders.
"We do recommend immunizations, because many of the diseases we immunize against are associated with regression in children with mitochondrial disorders," he said.
Vaccine-Autism Link: More Info
The court has not yet decided on the amount of damages. That decision, those close to the case say, could take a few months or more.
The federal Vaccine Injury Compensation Program was set up to ensure an adequate supply of vaccines, stabilize costs, and to provide an avenue for individuals injured by certain vaccines. The CDC web site says the program was triggered by reports in the early 1980s of harmful side effects following vaccination with the diphtheria, tetanus, and pertussis vaccine. As the number of lawsuits filed against vaccine makers increased, vaccination rates among children fell. Vaccine companies wary of liability began to drop out of the market. To help solve the situation, the National Childhood Vaccine Injury Act of 1986 established the compensation program.
The American Academy of Pediatrics in a statement, says the case "raised many questions."
"The AAP leadership is seeking access to official documents in the case so medical experts can examine the science and consider whether it raises implications for other children. The AAP wants to ensure the public is provided accurate information about the safety and importance of vaccines. Our members are dedicated to the health of all children and urge parents to fully immunize their children," the statement says.
(WebMD senior writer Daniel J. DeNoon contributed to this article.)