Vanderbilt investigators have found that childhood vaccinations do not harm children with a certain type of inborn errors of metabolism (IEM) called urea cycle disorders.
鈥淥ur study is one of the first to take a group that everyone would agree is going to be medically fragile and look at vaccines in this sub-group,鈥� said , a clinical geneticist and assistant professor of at Vanderbilt. 鈥淲e showed there is no association between vaccination and the illnesses these vulnerable children experience,鈥� Morgan said.
Vaccines not linked to illness
The impetus for the study, published this week in the journal , was the case of Hannah Poling, a 2-year-old girl from Athens, Ga. Shortly after receiving several vaccines, Poling fell ill and her behavior regressed. The chatty toddler began exhibiting some classic behavioral signs of autism. A physician鈥檚 group for the determined Hannah鈥檚 IEM 鈥� in her case a mitochondrial disorder – made her vulnerable to injury from vaccination. The family received more than $1 million in compensation for her injuries.
The case led to widespread concern than special populations of children might be at risk from vaccination.
Morgan鈥檚 study examined children with a group of IEM called urea cycle disorders. Through the , 169 children were enrolled and 74 cases were closely examined in which children had experienced both vaccination and an IEM-related illness serious enough to require hospitalization. IEMs are known to trigger serious side effects from stress on the body such as illnesses.
鈥淲e looked back from each child鈥檚 hospitalization seven and even 21 days before the illness and found no association with vaccinations,鈥� Morgan said.
Calming fears
He points out all children with IEMs are more vulnerable than children without such disorders to the illnesses the vaccines protect against. He hopes this study will help physicians and parents feel more comfortable providing vaccines to children with IEMs.
鈥淸rquote]I would hope that people who are skeptical about vaccines will see we take the issue seriously enough to actually study it. That鈥檚 what science does is provide information without having to rely on opinion,鈥� Morgan said.[/rquote]
Morgan said since Poling has a different type of IEM, vaccine safety should be studied in each of these disorders. He said this is the first study of its kind to show that children with an IEM are not harmed by vaccines.
Other contributors to the article include Cameron Schlegel, a fourth-year student who worked on the study as part of an Emphasis Project. , director of the ; Teresa Welch-Burke; Yuwei Zhu; and Robert Sparks are also contributors. Marshall Summar, former professor of Pediatrics and Molecular Biophysics at Vanderbilt, who now serves as chief of Genetics and Metabolism at Children鈥檚 National Medical Center in Washington, D.C., is senior author.
Funding for the study was supplied by the and from the .