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Do vaccines cause autism spectrum disorders (ASD)?

By: Dr. John Harrington, General Academic Pediatrics

This question arose in 1998 after a well-publicized article, published in the journal Lancet by British doctor Andrew Wakefield, claimed a link between childhood vaccines and autism. The article was later found to be fraudulent. It was discredited, retracted from the publication, and Dr. Wakefield was ultimately stripped of his medical license. Since then, despite overwhelming scientific evidence that vaccines are safe, groups of anti-vaccination activists have continued to claim that vaccines cause autism and other illnesses.

CHKD pediatrician Dr. John Harrington answers questions that CHKD pediatricians hear frequently from parents about vaccinations.

Does the MMR vaccine cause autism?

No, the MMR vaccine does not cause autism. The study by Andrew Wakefield, which claimed a link between the MMR vaccine and children diagnosed with autism, was found to have significant errors in the collection of data, along with evidence that Dr. Wakefield’s conclusions had been fabricated. Since that time, more than 200 authentic studies have shown no connection between the MMR vaccine and autism.

Does thimerosal cause autism?

Again, the simple answer is “no.” Thimerosal, a preservative which contains extremely small amounts of mercury, is used in some multi-dose vials of vaccine to prevent the growth of germs. The additive has been shown to be safe, and research does not show any link between vaccines containing thimerosal and autism. In addition, although fears of the preservative are unfounded, thimerosal is no longer used in young children’s vaccines, and thimerosal-free vaccines are available for older adolescents and adults.

Is autism caused by receiving too many vaccines too soon?

Although children receive more vaccines than they did years ago, they are actually exposed to fewer antigens than in the past. Antigens are the active component in a vaccine that causes the protective immune response. Combined, all 11 routinely recommended vaccines contain fewer than 130 antigens. Older vaccines contained many more, such as the 200 antigens contained in the smallpox vaccine. Every day a child encounters anywhere from 2,000 to 6,000 similar infectious proteins on shared toys, doorknobs, or playground equipment. Children today certainly get more shots than kids did years ago; however, they do not appear to have any side effects from these additional vaccines. Actually, a doctor recently looked at 1,047 children between the ages of 7 and 10 who had received all of their vaccines on time before age 2. He found no increases in neurodevelopmental problems such as , tics, poor memory, stuttering, or slowed response to stimuli.

What is the harm in delaying or withholding vaccines for my baby?

Vaccines are designed to protect the infant or child when they are most vulnerable. Delaying your child’s vaccines puts them at increased risk because contracting a vaccine-preventable disease at an earlier age is more likely to result in a serious complication or even death. I like to use the seat belt analogy: Many of us don’t get into our cars thinking we will get into an accident, yet we know that wearing a seat belt will protect us if we do. Would you consider putting your child in a car without a car seat and not buckled in? Giving Vaccines at the appropriate times is like buckling your child into a proper car seat and set belt.

It’s difficult to understand why parents would choose not to protect their child from meningitis and whooping cough with the vaccines. . When a young infant who has not been vaccinated develops a fever, we must do more invasive tests (spinal tap and blood cultures) because of possibility that they could be infected with a vaccine-preventable disease.

Back in 2000, I was a pediatrician in New York when a 5-month-old twin died from pneumococcal meningitis. The parent hadn’t had the chance to protect the baby from that illness because the vaccine was not yet available. The next month, the surviving twin was able to receive a newly released pneumococcal vaccine that would likely have prevented her sibling’s death. There is no doubt – giving vaccines on time and without delay can save lives.

The true cause of autism remains unknown. As mentioned above, numerous studies have found no link between any vaccine and autism, but the threat of vaccine-preventable diseases is real. It’s important that your children be immunized to prevent these life-threatening illnesses.

If you have questions about immunizations, please talk to your CHKD pediatrician.

Additional Resources from the AAP:

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About CHKD Medical Group

About CHKD Medical  Group Children’s Hospital of The King’s Daughters has been the region’s most trusted name in pediatric care for more than 50 years. As members of CHKD Health System, our pediatricians work closely with CHKD’s full range of pediatric specialists and surgeons. They also share a commitment to quality, excellence and child-centered care. With 18 practices in 29 locations throughout the region, a CHKD pediatrician is never far.