Immunization Issues

Mitochondrial Disorders and Vaccines

Updated: June 3, 2008

Mitochondria are the power factories within each cell in the body. Mitochondria are essential for survival as they provide the energy to drive all the cell functions. To maintain and increase power production requires coordination between the genes in the nucleus—that we inherit from our mothers and fathers—and tiny bits of genetic material in the mitochondria—inherited just from our mothers. The inheritance of genetic changes in mitochondria is complex because there are hundreds to thousands of mitochondria in every cell.

Over the past 15–20 years, researchers have increasingly recognized disorders of mitochondrial function. Children with a mitochondrial disorder may develop normally for a while, but when stressed—perhaps by infection or fever—they may be unable to make all the energy that they need. The brain requires a large amount of energy. So, when these children are stressed, the brain is the place most often affected; brain injury of this type is often called mitochondrial encephalopathy. Children with mitochondrial encephalopathy may develop a number of symptoms of brain injury: altered mental state, seizures, problems with walking, poor language skill, attention deficit disorder, and others. Although there is little compelling evidence that mitochondrial disorders are linked with autism, features of autism have been reported in some patients with mitochondrial disorders; mitochondrial abnormalities have also been found in some children with autism.1

In 2007, the National Vaccine Injury Compensation Program (VICP) conceded a case concerning a child with a mitochondrial disorder. Two days after being immunized, she developed fever, lethargy, irritability, prolonged screaming, decreased response to stimuli, and she refused to walk. During the next 10 days, these symptoms of encephalopathy continued, she could not climb stairs, and she had periods of arching backwards when she screamed. Over months, her symptoms evolved to include muscle weakness and some features of autism. Six years later she developed seizures.23

The VICP is a “no-fault alternative to the traditional tort system for resolving vaccine injury claims.”4 A family can be compensated if the child received a vaccine on the VICP list, had an injury recognized by the VICP (such as encephalopathy), and the vaccine either caused the injury or “caused an existing illness to get worse.” We think that the VICP conceded this case without a court ruling because the intent of the law is to compensate families without challenge when a case meets these preset statutory criteria, whether or not scientific causation has been established.

It is not possible to determine whether the onset of this child’s mitochondrial encephalopathy occurred coincidental in time with vaccination (for example, if she had an unrecognized viral illness) or whether the stress of vaccination unmasked the mitochondrial disorder.

There is no evidence that vaccines cause mitochondrial disorders. No practical tools for screening for rare mitochondrial disorders exist at the moment. At this time, our knowledge about mitochondrial disorders is incomplete, but we do know that children with mitochondrial disorders are at risk for encephalopathy after stress such as infections that can be prevented by vaccines.

This Immunization Issues essay is an excerpt from the book Do Vaccines Cause That?! A Guide for Evaluating Vaccine Safety Concerns written by NNii authors Martin G. Myers and Diego Pineda.


  • 1. Pons R, Andreu AL, Checcarelli N, et al. 2003. Mitochondrial DNA abnormalities and autistic spectrum disorders. Journal of Pediatrics144:81-5.
  • 2. Poling JS, Frye RE, Shoffner J, et al. 2006. Developmental regression and mitochondrial dysfunction in a child with autism. Journalof Child Neurology 21:170-72.
  • 3. United States Court of Federal Claims. November 9, 2007, Respondent’s Rule 4(c) Report. These reports are protected under the confidentiality provisions of the National Vaccine Injury Act. However, this particular report has been widely distributed on the Internet and reported in the media.
  • 4. National Vaccine Injury Compensation Program (VICP).