JUST as the dispute over whether vaccines cause autism was dying down at last, a US government decision has added fresh fuel to the fire. Last week it emerged that the federal government is to compensate a couple who say that the regular childhood vaccines, given to their baby daughter in 2000, caused her to develop autism. Damages have not yet been set, but could exceed $1 million. Significantly, the government’s decision says nothing about whether vaccines cause autism. Instead, government lawyers concluded only that vaccines aggravated a pre-existing cellular disorder in the child, causing brain damage that included features of autism.
Nonetheless, anti-vaccination campaigners are claiming vindication. “It’s official,” wrote one autism blogger. “The sky has fallen. The fat lady has sung. Pigs are flying. ” Autism experts say it is unclear why compensation is being paid. Almost 5000 other families have lodged similar claims which are being considered by the court, but decades of research have failed to find any link between vaccines and autism and few experts thought that the government would pay up. Scientists say there is nothing in the medical history of the child in question to change that thinking.
“I’m stunned that they decided to settle,” says Jay Gargus, a paediatrician at the University of California, Irvine. Exactly why the US government did so is still being debated, as details of the decision have been sealed and the Department of Health and Human Services won’t comment. Whatever the government’s thinking, the worry is that the decision may undermine public confidence in vaccines, which is just recovering after recent scares over mercury and the measles, mumps and rubella (MMR) shot.
On 29 February, for example, Republican presidential candidate John McCain used a query on the case as a chance to question whether mercury in vaccines could be linked to autism. “A decision like this will definitely make parents more wary about vaccines,” says Jaime DeVille, a paediatrician at the University of California, Los Angeles, and a member of the government’s childhood vaccines advisory committee.
According to internet newspaper The Huffington Post, which last week published leaked details of the court case from November, the child developed a fever after receiving scheduled vaccinations in 2000 for haemophilus influenzae, chickenpox, polio, MMR, diphtheria, pertussis, tetanus and polio, when she was 18 months old. Autism-like symptoms, such as poor communication skills, followed. In 2001 physicians concluded that the child, who has not been named, “demonstrated features of autistic disorder”.
It transpired that the child’s mitochondria, the powerhouses that provide cells with energy, were not working normally, and tests revealed a mutation in a gene linked to mitochondrial function. After studying her medical history, officials at the Department of Health and Human Services concluded that the vaccines had “significantly aggravated an underlying mitochondrial disorder, which predisposed her to deficits in energy metabolism”, causing brain damage with “features of autism spectrum disorder”.
Proponents of a link between vaccines and autism have made much of the mitochondrial disorder, in part because researchers have wondered for at least a decade whether autism could be a mitochondrial disorder. Autism runs in families and some of the genes thought to be involved play a role in mitochondrial function. Biomarkers for mitochondrial dysfunction, such as a build-up of lactic acid, are also elevated in some autistic children.
David Kirby, the journalist who revealed the decision, says that in an “informal survey” of seven other children with cases pending all show signs of mitochondrial problems, though he did not reveal how he got this information. Experts say these links do nothing to prove that autism originates in the mitochondria. “It’s not surprising that mitochondrial function is abnormal,” says Steven Novella, a neurologist at Yale University.
“With neurodegenerative disorders almost any marker of cell health will be worse than in controls. ” Without more research, he adds, it is impossible to say whether the mitochondrial problems are the cause of the disease or its by-product (see “Can autism be a mitochondrial disease? “). Those who argue otherwise, are “making multiple assumptions that are not established”, Novella warns. Further complications stem from confusion over the role vaccines played in the child’s condition.
Severe inflammatory reactions are a rare but established side effect of vaccines, and they can damage the brain in many different ways, some of which produce symptoms similar to those seen in autism. The mitochondrial disorder might have prevented the child from dealing with her inflammation, but it is also possible that the child’s mitochondrial problems caused the inflammation and that the vaccines she received were irrelevant. Other experts added that parents should not be dissuaded from getting their children vaccinated just because of a court case.
“What does this decision mean? ” says Paul Offit, a paediatrician at the Children’s Hospital of Philadelphia in Pennsylvania. “It doesn’t mean anything. The question of whether vaccines cause autism is a scientific one, not a legal one. ” Numerous scientific studies have addressed the question, adds Offit, and all concluded that there is no link. Government officials, including those at the Centers for Disease Control and Prevention in Atlanta, Georgia, also insisted the decision does nothing to change their thinking.
These caveats may, however, get lost as reaction to the decision evolves. Kevin Conway of Conway, Homer & Chin-Caplan in Boston, whose firm represents around 1200 autistic children with court cases pending, says he will start getting his clients tested for mitochondrial dysfunction. And Thomas Power, an attorney based in Portland, Oregon, says he would also like to see full details of the case, as they could help his cases of autistic children seeking compensation.