Message from the Chief Science Officer regarding the Institute of Medicine’s report on Adverse Effects of Vaccines
Geraldine Dawson, Ph.D., Autism Speaks Chief Science Officer
On Thursday, August 25, the Institute of Medicine’s Committee to Review Adverse Effects of Vaccines Board on Population Health and Public Health Practice released its report on the scientific evidence related to adverse effects of vaccines. The Institute of Medicine (IOM) is a non-profit, non-governmental organization which is part of the National Academy of Sciences. IOM members are scientific and medical experts who serve as pro bono as advisors to the U.S. Congress and other policy-makers. They are periodically asked to provide a review of the evidence on matters of public concern and welfare.
Among several other topics, the IOM committee specifically reviewed the evidence regarding whether the MMR vaccine or the DTaP vaccine is causally linked to autism. In addition to reviewing epidemiological evidence, they reviewed case studies and research on biological mechanisms that might explain a connection between a vaccine and an adverse outcome, such as autism. They specifically assessed the evidence that vaccines could alter neuronal development resulting in autism symptoms, arising from chronic encephalopathy, mitochondrial disorders or other underlying disorders. The committee reviewed 22 epidemiological studies that evaluated the connection between risk for autism and the MMR vaccine and concluded that the evidence does not support a causal link between the MMR vaccine and autism. The committee only found one study on the relationship between the DTaP vaccine and autism and concluded that the data were insufficient to assess an association.
The committee noted that reports of case studies linking the onset of autism to infectious diseases such as encephalitis and malaria suggest that infection or inflammation may underlie some cases of autism. Furthermore, evidence from postmortem brain tissue suggests that autism may involve inflammatory processes affecting the brain. The authors argue that, at a minimum, prior to ascribing autism to vaccination it would be important to rule out chromosomal and single-gene defects, including a variety of metabolic (e.g. mitochondrial disorder) and inflammatory or infectious diseases that may exist prior to vaccination.
The IOM report is consistent with Autism Speaks’ policy statement on vaccines. Given the present state of the science, the proven benefits of vaccinating a child to protect them against serious diseases outweigh the hypothesized risk that vaccinations might cause autism. Autism Speaks continues to support research that explores the relationship between innate or acquired metabolic, inflammatory, or infectious diseases that may play a role in the etiology of autism.
Autism Speaks Chief Science Officer Geraldine Dawson wrote a letter to the New York Times in response to an editorial entitled “Autism Fraud.”
To the Editor:
Re “Autism Fraud” (editorial, Jan. 13):
The latest British Medical Journal paper about autism and vaccines, which provides evidence that the initial report linking autism and vaccines was fraudulent, and the media coverage that ensued, miss an important point: Until science discovers the causes of autism and explains its dramatic increase, parents will continue to reach their own conclusions and desperately try a wide range of treatments, whether there is evidence to support them or not.
The answer is not to look to the past and look for blame, but rather to look to the future. We need increased research financing directed toward rigorous science that can provide the answers that parents are looking for and deserve. Until this happens, we will continue to wallow in controversy, and people with autism and families will continue to struggle with autism on their own.
Chief Science Officer, Autism Speaks
New York, Jan. 13, 2011
On Monday, September 13, 2010, the journal Pediatrics published the results of a scientific investigation that explored whether mercury exposure, through the vaccine preservative thimerosal, resulted in an elevated risk of autism. Using a case-control design, this study found no association between thimerosal exposure and autism, autism spectrum disorder, or regressive autism.
This study is unique from previous reports because it interviewed parents and used direct observations of child behavior to identify subgroups of autism, including regressive autism. All individuals who were included in the study, including those without autism, were screened using a tool called the Social Communication Questionnaire; thus, children with mild adverse neurodevelopmental outcomes that were not diagnosed as autism were not included. In order to calculate thimerosal exposure, the investigators documented thimerosal exposure through child and maternal medical charts and medical records. The analysis conducted also controlled for a wide variety of preexisting medical co-morbidities and potential confounding factors that were discussed and agreed upon by an external advisory committee.
No significant increase in risk of autism or regressive autism was observed with elevating levels of thimerosal exposure during any of the four time periods analyzed, including the prenatal period. The results of this study add to a large body of literature showing that thimerosal is not associated with a higher risk for autism. Thimerosal has now been removed from childhood vaccinations due to public concern over the preservative. . Details about the study, including rationale for the adjusted analyses and confounding variables, and additional analyses can be found on the website of the independent agency contracted to conduct the study.
For more information, please read Autism Speaks statement on the vaccines and autism.
The words “vaccine” and “autism” hit the news again this weekend with the release of the award to compensate the Poling family for pain, suffering, future care and lost wages for their nine year old daughter, Hannah.
Hannah was developing typically until a regressive episode at 18 months that closely followed the 9 vaccinations she received at a well-baby visit. Further testing revealed that Hannah 1) developed autism and 2) had the metabolic signature of a mitochondrial disorder which may have made her vulnerable to injury from the vaccines themselves or the fever that commonly accompanies vaccines and many childhood illnesses.
Although this case has been long fought, the recent award is renewing questions in the autism community.
How common are mitochondrial disorders?
The field of mitochondrial medicine is relatively young, but growing in importance. The United Mitochondrial Disease Foundation (UMDF), with whom Autism Speaks has partnered in an effort to learn more about mitochondrial disorders and autism, reports “while exact numbers of children and adults suffering from mitochondrial disease are hard to determine because so many people who suffer from mitochondrial disease are frequently misdiagnosed, we now know the disease is approaching the frequency of childhood cancers.” Mitochondrial disorders are more broadly defined and therefore possibly more frequent than frank mitochondrial disease, which is typically defined by identifying a known causative mutation. For more on mitochondrial disease and disorders, please see ‘What is Mitochondrial Disease?‘ on the UMDF website.
Testing for mitochondrial disorders is notoriously difficult in part because the field is young and misdiagnoses are common. However, identifying dysfunctional mitochondria in autism and mitochondrial disorders is an area where Autism Speaks has invested in a High Risk, High Impact grant from Autism Speaks awarded to expert clinicians and researchers investigating mitochondrial disorders at University of California at Irvine and University of California, San Diego. Through research and partnership with the UMDF (read story about our recent joint symposium), we hope to shed more light on “mitochondrial autism,” including how it is identified and how best to treat it.
Are there other reports of mitochondrial disorders and autism?
In 2009, John Shoffner, M.D. reported a study of 28 children with an identified mitochondrial disease and autism, looking at the effect of fevers on regression.
One of our investigators in the aforementioned grant, Robert Naviaux, M.D., Ph.D., has written a detailed commentary for the public on these data.
Should this information change my plans to vaccinate my child?
No. The recent award pertains to a legal decision not a new scientific discoveries— it is news and not new science. Therefore, no new recommendations are warranted.
Several epidemiological studies have explored whether either the MMR vaccine or thimerosal, a preservative previously used in vaccines, are linked to autism, and these studies have not supported a link. However, these studies were not designed to identify effects in a small population of potentially vulnerable children due to rare genetic and/or medical conditions.
We are seeking to understand if vulnerable populations exist, including children with unidentified mitochondrial disorders, and if so, how we identify them early so they can be protected from public health threats in the safest manner possible. For more information please see our vaccine statement and an interview with Dr. Geraldine Dawson, Autism Speaks’ Chief Science Officer, about vaccines and autism.
We recognize that this is a sensitive topic in our community. Please be respectful to the opinions of others and especially to the Poling family who has endured the spotlight for too many years.
Autism Speaks recently awarded 16 new autism research grants, totaling over five million dollars. You can learn more about them here.
On April 11-13, 2010, over 30 individuals from a range of sectors and perspectives met in Salt Lake City to provide thoughtful input on the enhancement of the national vaccine safety system. Named the “Salt Lake City Writing Group”, the meeting was convened by the Vaccine Safety Working Group (VSWG) of the National Vaccine Advisory Committee (NVAC). Invited attendees included Peter Bell, Autism Speaks’ executive vice president of programs and services, and Sallie Bernard, Autism Speaks board member and Executive Director of SafeMinds. For the purposes of this meeting, participants were asked to bring their experience and expertise to bear on this issue, but were not asked or expected to represent the official views of their organizations of affiliation.
The NVAC advises the U.S. Department of Health and Human Services (HHS) on issues of vaccine policy. In 2008, NVAC formed a Vaccine Safety Working Group (VSWG) with two charges: first, to review and provide comment on the Centers for Disease Control’s Immunization Safety Office’s draft Scientific Agenda; second, to review the current federal vaccine safety system. Specific to the second task, the VSWG is charged with developing a White Paper (for consideration and possible adoption by the NVAC) describing the infrastructure needs for a federal vaccine safety system.
As part of these efforts, NVAC committed to meaningful public and stakeholder engagement. For the VSWG’s second charge, that process includes both the recently concluded meeting in Salt Lake City and a meeting of a broader group of stakeholders is expected to take place in Summer 2010 in Washington, D.C.
The accompanying memorandum from the Writing Group provides some highlights of the discussion that took place on April 11-13.