CDC Report: Vaccines Not Associated With Risk of Autism
Findings support conclusion of 2004 review (Mar. 29)
A new study that evaluated parents’ concerns about “too many vaccines too soon” and autism has been published online in the Journal of Pediatrics.
According to the Centers for Disease Control and Prevention (CDC), the report adds to the conclusion of a 2004 review by the Institute of Medicine (IOM) that a causal relationship does not exist between certain vaccine types and autism.
The new study looked at the amount of antigens from vaccines received on one day of vaccination and the amount of antigens from vaccines received in total during the first 2 years of life and found no connection to the development of autism spectrum disorder (ASD) in children.
The researchers collected data from three managed care organizations in a group of 256 children with ASD compared with 752 children without ASD.
The study’s main findings include:
- The total amount of antigens from vaccines received was the same between children with ASD and those that did not have ASD.
- Children with ASD with regression (the loss of developmental skills during the second year of life) did not receive an increased number of vaccine antigens compared with children without ASD with regression.
- The number of vaccine antigens has decreased in recent years.
Although the routine childhood vaccine immunization schedule in 2013 contains more vaccines than the schedule in the late 1990s, the maximum number of vaccine antigens to which a child would be exposed by 2 years of age in 2013 is 315, compared with several thousand in the late 1990s, according to the CDC. This is due to changes in the vaccines. For example, the older whole-cell pertussis vaccine causes the body to produce about 3,000 different antibodies, whereas the newer acellular pertussis vaccines cause the production of six or fewer different antibodies.
An infant’s immune system is capable of responding to a large amount of immunologic stimuli, and from the time of birth, infants are exposed to hundreds of viruses and countless antigens that are not associated with vaccination, the CDC says. The new study demonstrates that ASD is not associated with immunological stimulation from vaccines during the first 2 years of life, the agency concludes.