Top federal health authorities Thursday reiterated that vaccines do not cause autism after government health officials acknowledged that a vaccine, by worsening an underlying genetic condition, may have triggered autismlike symptoms in one girl.
The case is viewed as an important milestone by autism groups that maintain that vaccinations are connected to autism.
But Dr. Julie Gerberding, director of the U.S. Centers for Disease Control and Prevention, emphasized that the concession should not be interpreted to mean that vaccines cause autism.
"The government has made absolutely no statement about indicating that vaccines are the cause of autism, as this would be a complete mischaracterization of any of the science that we have at our disposal today," Gerberding said during a Thursday news conference. "I think we need to set the record straight on that."
And some vaccination experts said the legal rulings were an example of the courts taking action ahead of the evidence needed to justify such a move.
Still, on the steps of a U.S Federal Court in Atlanta Thursday morning, Athens, Ga., neurologist Dr. Jon Poling and his wife, Terry Poling, made it clear that they believed vaccines triggered the encephalitis that led to their 9-year-old daughter Hannah's autismlike symptoms.
"I wanted to know why my daughter, who had been completely normal until she received [five vaccines for nine different diseases], in one day was no longer there … no longer responding," Terry Poling told the crowd of reporters present.
The Polings said Hannah received the battery of vaccines in 2000, when she was 19 months old. Shortly after these shots, they said she suffered from a fever that left her screaming and arching her back. Following this, they said, Hannah began showing classic signs of autism — staring at lights, running in circles and staring at fans.
On Friday, the Polings appeared on ABC's Good Morning America, where Jon Poling reiterated his view that a mercury-containing ingredient called thimerosal was reponsible for his daughter's condition — and that he believes his daughter was not the only one affected in this way by vaccines.
"I think that Hannah's case … is echoed among thousands of similar cases," he told ABC's Chris Cuomo. "I know a lot of other medical experts are going to get out there and say this is a very unusual, oddball case. We don't really think it is at all."
But doctors overwhelmingly maintained that the case will have no effect on guidelines that urge parents to have their children vaccinated against disease. And they said that the fears spurred by this case could end up doing more harm than good to the nation's children.
They added that there is as yet no evidence providing a reliable link between vaccination and the worsening of underlying mitochondrial diseases such as the one suffered by Hannah Poling.
Dr. Pauline Filipek, associate professor of clinical pediatrics and neurology at the University of California Irvine School of Medicine, and her colleagues conduct research into a possible connection.
"Mercury has long been known to be a mitochondrial toxin, and could potentially interact with underlying genetic vulnerability of deficient mitochondria," she said. "That said, there remains no epidemiological data that we are aware of that implicates vaccination in autism or in mitochondrial disorders."