CDC: No Link Between Vaccines, Diabetes
But critics question study results
MONDAY, Dec. 3, 2001 (HealthDayNews) -- Routinely vaccinating your child doesn't mean he or she will come down with insulin-dependent diabetes, a devastating disease that tends to strike the immune systems of the young.
That's what the Centers for Disease Control and Prevention (CDC) says it found when researchers compared vaccination records of 252 children diagnosed with Type I diabetes with records of 768 children who did not have the disease. Despite earlier studies that suggested a link between certain vaccines and Type I diabetes, the CDC scientists say there was no increased risk for the disease no matter at what age the children received the vaccines. The study appears in the Dec. 1 issue of Pediatrics.
With Type I diabetes, the immune system attacks the cells that produce insulin in the pancreas, and you lose the ability to metabolize sugar. Insulin shots become a part of your daily life, and 20 to 30 years later your organs can begin to fail, and various side effects can happen, including loss of vision.
But CDC researchers say parents don't need to worry about vaccines spurring this disease in their children.
"I think the evidence that's accumulated now suggests there's not much there to say vaccines, any vaccines, cause diabetes. I think our study, taken in context with previous research, pretty much settles most of the issues," says Dr. Frank DeStefano, lead author of the study. "All the evidence shows the benefits outweigh the risks."
But that doesn't convince Barbara Loe Fisher, president of the National Vaccine Information Center.
She says her biggest problem with the CDC study is that the research was done by the same agency that sets policy on childhood vaccinations.
"There's a gross conflict of interest when the same officials involved in making vaccine policy and advocating it are also involved in research of adverse events," Fisher says. "I think it is not scientifically responsible to have this kind of study supposedly set to rest forever the issue of vaccines and diabetes. It causes a false sense of security."
But her problems with the CDC study get more specific.
"It's too small a sample. The numbers are low for new vaccines," she says, adding that all the kids in the study had been vaccinated, so there was no control group. She admits it would be tough to do a study in this country with a large control group of unvaccinated children, given the federal government's requirements for childhood vaccinations.
Dr. Bart Classen, a researcher who has studied a possible link between vaccines and diabetes for more than 10 years, also takes issue with the size of the study and how it was conducted.
More importantly, Classen, an immunologist, notes that while the CDC study found the same thing his larger studies have found, the CDC researchers deemed the increased risk statistically insignificant. He says his studies have looked at hundreds of thousands of children at a time.
"They're saying there's a 10 percent increase in risk, but it's not significant. We think it is," says Classen. "Their data indicate a potential risk of 10 percent or greater. They put a spin on it, and just say it's still safe. Their data are still consistent with what we're finding. I'm the only one who has kind of got the courage to stand up to these people."
DeStefano defends the CDC study as scientifically sound.
"I think we tried to do it as objectively as possible. We laid out our methods and submitted it to peer reviewers," he says. "We used significant, rigorous mechanisms to address these concerns about vaccines. I think concerns about the risk of diabetes shouldn't enter into parents' decisions about vaccinations."
But Classen says parents should give pause before agreeing to each and every vaccine for their child.
"You inject complex stuff that's difficult to metabolize. The white blood cells get hyperactive and destroy their own tissue," he says. "My opinion is that, as our data shows, the risk exceeds the benefits. Parents should withhold some vaccines."
What To Do
The vaccines that have raised the most red flags include: hepatitis B; tuberculosis, or BCG; and Haemophilus influenzae type b, or Hib. But Classen says the varicella vaccine, used to ward off chicken pox, and the DPT vaccine, which protects against diphtheria, are also suspect.
For more on vaccines and diabetes, go to the CDC.
The National Vaccine Information Center makes the case for a possible link between vaccines and diabetes.
To learn more about childhood immunization, check the American Academy of Family Physicians.
Before you consent to any vaccine for your child, read about the risks and benefits and discuss both with your physician. The American Academy of Pediatrics has a list of recommended vaccines.