The parents of 9 year-old Hannah Poling spoke to the media this week about the US government’s landmark decision to pay compensation following their claim that childhood vaccines caused their daughter’s autism. The government’s sealed decision, made last November, was recently made public on an autism advocacy group website.

The payout, the extent of which is yet to be decided, comes from a federal fund that compensates victims of vaccine-related injuries. The ruling effectively states that Hannah’s pre-existing rare mitochondrial disorder had disposed her to autism and this was “significantly aggravated” by the vaccines she received as a toddler eight years ago.

Hannah’s father, neurologist Dr Jon Poling who practised in Athens, Georgia, told the press on Thursday that he and his wife, Terry, a registered nurse and former trial attorney, were ” very pleased” with the decision, reported CNN.

Poling said he and his wife had endured “eight difficult and heartbreaking years since our daughter’s injury”.

While conceding that childhood vaccines contributed to Hannah’s autism, government health officials maintain that there is no proof that they cause autism directly. The government decision does not support the parents’ claim, they said.

Director of the US Centers for Disease Control and Prevention (CDC), Dr Julie Gerberding said:

“The government has made absolutely no statement indicating that vaccines are a cause of autism.”

“This does not represent anything other than a very specific situation and a very sad situation as far as the family of the affected child,” said Gerberding, and urged parents to “continue to get their children immunized”, because it is “proven to save lives,” reported CNN.

Terry described her daughter as “precocious” in her first 18 months, before receiving 9 routine childhood vaccines in July 2000. After that her health declined rapidly, she said. Hannah stopped eating, did not respond when spoken to, and started having bouts of screaming and high fever.

She started showing all the symptoms of autism said Terry Poling, who added that it broke Hannah’s father’s heart.

Both parents gave up their jobs to spend more time with Hannah, and in 2002 they filed their case, alleging that the childhood vaccines had caused their daughter’s autism.

Jon Poling said Hannah, like her mother, has a rare inherited mitochondrial disorder. Mitochondria are the “power batteries” inside every cell of the body and supply the cell with energy.

Poling said the fact that his wife did not have autism showed Hannah did not inherit it from her mother, and contended it was the mercury in the vaccine preservative thimerosal that triggered the condition in their daughter.

The Poling’s lawyer said their case had been consolidated with other claims, and the government agreed to settle just before an expert testimony was to be filed. He said the family was willing to make their case public, but the court had ruled it should stay secret.

Experts have been cautious about generalizing from this case, suggesting it is more of an exception than a rule.

Dr Jennifer Shu of the the American Academy of Pediatrics told NBC4 that “you can’t generalize and say, OK, now every child with a mitochondrial disorder is going to go through same thing that Hannah did”.

There are many unknowns and while the government maintains there is no proven link between childhood vaccines and autism, there are some 5,000 cases in the pipeline, reports NBC4. Hannah’s case is being watched closely and is being described as a landmark.

Speaking to WebMD, Jon Poling pointed out the difference between proving a link scientifically and proving it legally.

“When you are talking about the courtroom versus science”, said Poling, “the burden of proof is different”.

“We showed there was a plausible mechanism, we showed that an injury occurred shortly after her vaccination. Her growth curve went flat for months,” he told WebMD.

After all their experience with Hannah, the Polings said they are not against vaccines.

As Jon Poling explained to WebMD:

“I want to make it clear I am not anti-vaccine. 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,” he added.

Poling said that as with every medical treatment, risks exist, and to say they do not is not true. They have to be weighed against the benefits, and sometimes people are injured by a vaccine, but for the vast majority of people they are safe.

“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,” said Poling.

Hannah’s mother, Terry, told the press yesterday:

“We are absolutely pro-vaccine. What we want is safe vaccines.”

Terry and Jon Poling said they did not think their story was unique and they feared other families could be in the same position.

According to the CDC, thimerosal, a vaccine preservative that contains mercury, was removed from childhood vaccines after an agreement made in 1999 between vaccine makers, the American Academy of Pediatrics and public health authorities. However, childhood autism rates continued to climb after this.

Studies published in respected medical journals have found no link between childhood vaccines and autism, and leading institutions such as the Institute of Medicine, the American Academy of Pediatrics, as well as government agencies like the CDC, maintain there is no known link.

About one in 150 children have autism, according to the CDC.

Sources: CNN, WebMD, NBC4, CDC.

Written by: Catharine Paddock, PhD