The recent settlement between the parents of an autistic child and the federal government's vaccine compensation program, which suggested that vaccines may have helped exacerbate the child's autistic symptoms, has rekindled the debate over the safety of childhood immunizations.

But what's important to note is that this case had several unique characteristics. Indeed, the Centers for Disease Control, which administers the compensation program, stressed that the settlement is in no way a statement that vaccines cause autism.

First, Hannah Poling's case is unique. She had a rare cellular disorder, which the vaccine court determined may have put her at increased risk of adverse reactions to vaccines. Even then, experts on mitochondrial disorders say there are no scientific studies that show vaccinations worsen or cause mitochondrial disease symptoms.

Second, Hannah received an unusually large amount of vaccines. Because she had been sick earlier and had fallen behind schedule, she was given five inoculations in a single day.

Study after study has shown that there is no medical evidence to suggest any link between the mercury in thimerosal, which is used in some vaccines, and autism. Thimerosal was removed from most childhood vaccines. Hannah, now 9, had received her vaccines in 2000, when thimerosal was still in use.

In fact, Hannah's father, Dr. Jon Poling, a neurologist, said he still believes in the importance of vaccinating children; he urged pediatricians to examine vaccine schedules, so that not so many shots are administered at once.

So while it's important to recognize the risks associated with all medicines, parents should recognize that the benefits and the protection that vaccines offer far outweigh them.

As state epidemiologist Dr. Paul Effler rightly notes: "We need to put this in perspective and recognize that vaccines are one of the most beneficial medical interventions that exist ... this event is exceedingly rare and should not scare parents away."