JPeds: Autism NOT Linked To Timing & Number Of Childhood Vaccines

 

 

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Despite a lack of any credible scientific evidence to support the notion, many parents believe that the number and timing of recommended childhood vaccinations increase the risk of their child developing autism.

 

This has become a hot button issue, and a centerpiece of the anti-vaccine movement’s rhetoric.

 

While unlikely to appease hardcore anti-vaccine activists, hopefully most parents will be reassured by the following CDC study that appeared overnight in the Journal of Pediatrics. 

 

Researchers found no relationship between the number, or timing, of childhood vaccines and the development of autism spectrum disorder.

 

First stop, a press release/editorial, followed by links to the study in the Journal Pediatrics, and an NPR blog.

 

 

The risk of autism is not increased by 'too many vaccines too soon'

Cincinnati, OH, March 29, 2013 -- Although scientific evidence suggests that vaccines do not cause autism, approximately one-third of parents continue to express concern that they do; nearly 1 in 10 parents refuse or delay vaccinations because they believe it is safer than following the Centers for Disease Control and Prevention's (CDC) schedule.

 

A primary concern is the number of vaccines administered, both on a single day and cumulatively over the first 2 years of life. In a new study scheduled for publication in The Journal of Pediatrics, researchers concluded that there is no association between receiving "too many vaccines too soon" and autism.

 

Dr. Frank DeStefano and colleagues from the CDC and Abt Associates, Inc. analyzed data from 256 children with autism spectrum disorder (ASD) and 752 children without ASD (born from 1994-1999) from 3 managed care organizations. They looked at each child's cumulative exposure to antigens, the substances in vaccines that cause the body's immune system to produce antibodies to fight disease, and the maximum number of antigens each child received in a single day of vaccination.

 

The researchers determined the total antigen numbers by adding the number of different antigens in all vaccines each child received in one day, as well as all vaccines each child received up to 2 years of age. The authors found that the total antigens from vaccines received by age 2 years, or the maximum number received on a single day, was the same between children with and without ASD. Furthermore, when comparing antigen numbers, no relationship was found when they evaluated the sub-categories of autistic disorder and ASD with regression.

 

Although the current routine childhood vaccine schedule contains more vaccines than the schedule in the late 1990s, the maximum number of antigens that a child could be exposed to by 2 years of age in 2013 is 315, compared with several thousand in the late 1990s. Because different types of vaccines contain varying amounts of antigens, this research acknowledged that merely counting the number of vaccines received does not adequately account for how different vaccines and vaccine combinations stimulate the immune system. For example, the older whole cell pertussis vaccine causes the production of about 3000 different antibodies, whereas the newer acellular pertussis vaccine causes the production of 6 or fewer different antibodies.

 

An infant's immune system is capable of responding to a large amount of immunologic stimuli and, from time of birth, infants are exposed to hundreds of viruses and countless antigens outside of vaccination. According to the authors, "The possibility that immunological stimulation from vaccines during the first 1 or 2 years of life could be related to the development of ASD is not well-supported by what is known about the neurobiology of ASDs." In 2004, a comprehensive review by the Institute of Medicine concluded that there is not a causal relationship between certain vaccine types and autism, and this study supports that conclusion.

The study may be accessed in PDF form at:

 

"Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with risk of autism,"

by Frank DeStefano, MD, MPH, Cristofer S. Price, ScM, and Eric S. Weintraub, MPH, appears in The Journal of Pediatrics (www.jpeds.com), DOI 10.1016/j.jpeds.2013.02.001, published by Elsevier.

 

For more on all this, NPR’s Shots blog has the following report and audio story.

 

Number Of Early Childhood Vaccines Not Linked To Autism

by Jon Hamilton

March 29, 2013 3:08 AM

Listen to the Story

Pediatrics: Low Uptake Of Flu Vaccine Among Toddlers In Ontario

 

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Despite a universal vaccination program that began in the year 2000, a study published today in the journal Pediatrics indicates that flu vaccination rates among young children (aged 6 mos- 23 mos) in Ontario, Canada (analyzed between 2002 and 2008) never exceeded 10%.

 

This in spite of a SARS outbreak in 2003, and a high publicized serious flu season in 2003-04. This study did not extend into the 2009-10 pandemic flu season.

 

The authors suggest that `vaccine fatigue’ among parents may be a major factor in this low uptake, but acknowledge that several other Canadian provinces are doing a better job at getting kids vaccinated.

 

With the large number vaccines recommended for young children - and unfounded fears among some parents (popularly spread in the media and online) that too many inoculations, too soon, can cause serious health problems – some doctors are having to decide which vaccines to promote to parents as being the most important.

 

First the journal article, then a link to Helen Branswell’s coverage of this story.

 

Low Rates of Influenza Immunization in Young Children Under Ontario’s Universal Influenza Immunization Program

Michael A. Campitelli, MPH, Miho Inoue, MD, MSc, Andrew J. Calzavara, MSc, Jeffrey C. Kwong, MD, MSc, and Astrid Guttmann, MDCM, MSc

Abstract

OBJECTIVES: To determine physician-administered influenza vaccine coverage for children aged 6 to 23 months in a jurisdiction with a universal influenza immunization program during 2002–2009 and to describe predictors of vaccination.

<SNIP>

CONCLUSIONS: Influenza vaccine coverage among children aged 6 to 23 months in Ontario is low, despite a universal vaccination program and high primary care visit rates. Interventions to improve coverage should target both physicians and families.

 

 

Helen Branswell of the Canadian Press has more on all of this in her article:

 

May 14, 2012 Updated: May 14, 2012 | 6:52 am

Flu shot program misses children under two in Ontario: study

 

 

While far from perfect, flu vaccines remain our best protection against influenza, seasonal or otherwise. They have an enviable safety record, and most years they provide a moderate level of protection against currently circulating flu strains (see A Comprehensive Flu Vaccine Effectiveness Meta-Analysis).

 

Unfortunately, a combination of bad press from anti-vaccine activists, memories of the ill-fated 1976 H1N1 vaccination campaign (see Deja Flu, Once Again), and the mistaken belief that influenza is a mild illness all lead to many in the public to avoid getting the flu vaccine each year.

 

Our most recent mild flu season notwithstanding, most years influenza claims tens of thousands of lives in North America, including those of hundreds of children.

 

Convincing the public of the wisdom of getting the shot every year, however, remains a difficult task.