Press Briefing Transcripts
Media Availability on Vaccine Safety
March 6, 2008
OPERATOR: Welcome, and thank you for standing by. At this time, all participants are in a listen-only mode. During the question-and-answer session today you can press star one to ask a question. Today′s conference is being recorded. At this time, we′ll turn the call over to Glen Nowak, you may begin sir.
GLEN NOWAK: Thank you. And thank you all for taking time off this afternoon to join us. This is a call on the science of vaccines and autism, and to answer some of those – the questions that many of you had and have been calling the various HHS agencies about in the past day or so. I do want to note, we are not here to discuss the specific vaccine injury compensation case that has received a lot of media interest. I realize, this is related to that case, but we are unable to talk about the specifics of that case.
We do, however, recognize that, you know, many media stories have likely prompted new questions, caused some confusion, introduced some new medical terms and concepts, such as greater awareness of mitochondrial diseases and disorders. And so given the range of questions and interests that we′ve been getting the last day or so, we have a number of people here today to help answer your questions. They include Dr. Bruce Gellin, Director of the National Vaccine Program Office at the Department of Health and Human Services. Dr. Julie Gerberding, Director of the Centers for Disease Control and Prevention. Dr. Thomas Insel, Director of the National Institute of Mental Health at the National Institutes of Health. And because many of you have been calling us at CDC about mitochondrial diseases we also have Dr. Edwin Trevathan, Director of CDC′s National Center for Birth Defects and Development Disabilities with us today. Edwin is a pediatric neurologist whose expertise includes these diseases and disorders.
And then, we also have available to us Dr. Norman Baylor, who′s Director of the Office of Vaccines Research and Review in the Center for Biologics Evaluation and Research at the Food and Drug Administration. And Dr. Anne Schuchat, Director of CDC′s National Center for Immunization and Respiratory Diseases. We′re going to have a couple of those people make some brief opening remarks. I′m going to have Dr. Gerberding start and then we′ll follow with Dr. Insel who′s going to make some brief remarks about autism. Followed by Dr. Trevathan who′s going to provide a brief overview on mitochondrial diseases and disorders. So. Dr. Gerberding.
DR. JULIE GERBERDING: Thank you, and I appreciate everyone coming together on short notice for this conversation. Today is, again, a very kind of sad reminder of how difficult autism is for so many families. And while we can talk about lots of different aspects of this I want to be real clear from the beginning that probably the most important aspect of this is the fact that autism is a very serious and challenging disease for many families and each of these families has to struggle to understand and cope with the condition and we wish we could be more helpful in supporting all of that.
We also recognize that some of the information that′s being promulgated about this particular situation is not accurately characterizing what we understand to be the true situation. So let me just be very clear that while we recognize and have recognized for a long time that mitochondrial disorders can be associated with nervous tissue degeneration and muscle tissue degeneration and that autism like systems are sometimes a component of that there′s nothing about the particulars of this situation that should be generalized to an understanding of the risks associated with vaccines for normal children and certainly nothing in any of this is going to change any of our recommendations about the importance of childhood immunization for every child for whom these immunizations are otherwise indicated.
I want to say that again. Our message to parents is that immunization is lifesaving. There′s absolutely nothing changed in the adamant recommendations that we are making to get children vaccinated. This is proven to save lives and is an essential component of health protection for children across America and the world.
CDC and FDA and NIH and really all of the parts of Health and Human Services (HHS) want to do the very best we can to protect the health and safety of children everywhere. And we also recognize that we don′t know everything we need to know about autism. And, I think, we need to have an open mind about causes of autism even if they′re rare or unusual causes of autism. And we are very committed to the interagency research process that′s been going on at HHS to try to define the most critical research requirements to work with families and advocates for children with autism and really do more faster to try to get to the bottom of what is obviously a very complicated and difficult disease to understand, identify early and treat.
So we know we need to do more and we′re committed to that. But in the meantime we need to disassociate the issue of autism with the very important public health and health protection intervention of immunizations for children.
GLEN NOWAK: Thank you, Dr. Gerberding. Dr. Insel.
DR. THOMAS INSEL: Thank you. I′m happy to be with you. And I′ll just take a moment to say something generally about autism. As Dr. Gerberding just said this is a complicated and difficult disease. It′s actually a group of developmental disorders which have a diverse range of symptoms that vary a lot in severity. The way we think about autism is that there are three core aspects to it. One is that deficits in social behavior so kids don′t have eye gaze or social place. There are deficits in language. Some children have no language whatsoever. And there′s also these increased repetitive stereotype behaviors. Sometimes you see hand flapping or a very focused interest that often go with autism.
I should underline the fact that as Dr. Gerberding said it′s complicated. And we tend to think about this, actually as a group of disorders. Sometimes we talk about autisms rather than autism per se. The one thing they have in common are those three factors and the fact that they all by definition begin before age three.
For most cases, we actually don′t have a cause. There are some forms of autism that will occur as part of other – part of genetic diseases fragile X, tuberous sclerosis and there are a few others that frequently have autism as part of the overall syndrome. And there are some cases of autism in which we find genetic lesions. But, in fact, most cases are probably likely due to both genetic and environmental factors. And just as we haven′t identified genetic lesions in most cases, in just about all cases we haven′t been able to identify a clear and environmental cause. So there′s lots of interest in trying to think about what those environmental factors may be but we have a long way to go before we′ve been able to pin down the most important ones.
As Dr. Gerberding mentioned, there′s a lot of research in this area. The research is in the diagnosis to causes, trying to find some new treatment. There′s funding, in this case, from both federal and from private organizations. And so it′s a very active area of science. And the science is covering a whole range, as I mentioned, a whole range of different questions that parents want to know about.
I should just finish by saying that this is a disorder in which the department has organized this Interagency Autism Coordinating Committee (IACC). And this is really an extraordinary effort here to both expedite and coordinate research on autism across all of these different sectors and all of these different areas. To try to make sure that we do develop the kinds of answers that families – for the questions that families are asking.
We certainly have a sense of the urgency here, and a sense of the importance. But we have a ways to go yet, before we are able to really pin down many of the factors that seem to be most important for cause and the factors that will lead us to the new treatments that all of us are so committed to. Thank you.
GLEN NOWAK: Thank you, Dr. Insel. And again, because many of you have been asking us questions in the last day or so about mitochondrial disease and disorders, we have Dr. Ed Trevathan here to talk about that and give you a brief overview. Ed.
DR. ED TREVATHAN: Thanks, Glen. It′s good to be here today. When we talk about mitochondrial disorders, what we′re really discussing are a group of rather heterogeneous genetic disorders. They are disorders of function of the mitochondria. And we often remember mitochondria from grade school or high school science as the powerhouse of the cells. And, in fact, that is a key thing to remember because the children who have mitochondrial disorders or these genetic disorders can appear normal initially.
But when placed under severe stress due to infections or vomiting, diarrhea, dehydration, fever, other sorts of stress like perhaps sever sleep deprivation or malnutrition they′re not able to make enough injury to compensate for their severe energy needs. And because the brain actually has such a high need for energy and utilizes a large amount of energy, when these children are under stress the brain is really the organ that tends to often suffer the most. And so, when they′re under severe stress, often for a variety of different reasons and the reasons can vary from child to child based on which severe source of stress happens first, they tend to have severe neurological deterioration and decompensation that′s manifested by a loss of normal neurological function.
And the type of loss of function that occurs is actually dependent upon what part of the brain is affected by the deterioration of function because of inadequate energy supplies. So, for example, children that have problems in areas of the brain that control movements, such as the basal ganglia. Those children have problems with muscle tone and can become spastic and have difficulty walking, for example. And children that have severe problems with the cerebral cortex of the gray matter of the brain often have seizures and have poor responsiveness and can then often have severe problems with language and cognition and sometimes also social behavior.
The children who have mitochondrial disorders even though they can appear normal initially are actually somewhat predestined to have a regression of neurological function when placed under stress. And that makes it extremely difficult for parents, of course, to watch their previously normal appearing child suddenly deteriorate. And although most children with mitochondrial disorders do not have autism they have other neurological manifestations such as severe epilepsy or severe problems with movement, the one thing they tend to have in common is that they′re normal appearing in spite of their underlying mitochondrial disorder until they exhibit signs of the disease when they′re placed under severe stress.
So at this point, we know quite a lot about how mitochondrial disorders can affect the brain but we still have a lot that we need to learn. There′s much research that needs to be done. But, I think, we do know enough to know that there are multiple different sources of biological stress for children with mitochondrial disorders including, I might add, some of the infections that we immunize against, such as pertussis or flu.
So that′s worth keeping in mind I think in this discussion. And, I think, it′s also worth noting that most children with autism do not seem to have a mitochondrial problem. And so this association between mitochondrial disorders and autism is actually probably relatively rare. But the association between mitochondrial disorders and severe brain damage and dysfunction is one that is not as rare and is actually quite important.
GLEN NOWAK: Thank you. And with that, we′ll open the line for some questions. If you would, please identify if there′s someone you would like to direct a question to please let me know who that is. So, operator, we can take the first question.
OPERATOR: Thank you. We will now begin the question-and-answer session. If you would like to ask a question, please press star one. You will be prompted to record your name. Again, if you′d like to ask a question press star one. To remove your question, you may press star two. And one moment for our first question.
Our first question comes from Daniel DeNoon. You may ask your question, and please state your affiliation.
DANIEL DENOON: Hi, this is Dan DeNoon at WebMD. Thanks for doing this. Is this – I see occasionally it written that there′s a higher prevalence of mitochondrial disorders among children with autism than among the general population. Could you all address this please?
GLEN NOWAK: I guess I′ll have Dr. Trevathan and then I′ll turn it over to Dr. Insel, if he wants to add anything.
DR. ED TREVATHAN: Yes, I think that I would say that is really more a hypothesis than a statement of fact. It′s been recently raised as a possibility. The truth is we don′t know the exact prevalence of mitochondrial disorders in the general population. Those data are somewhat difficult to determine. One of the reasons, by the way is because mitochondrial disorders are extremely difficult technically to diagnose, at least in terms of verifying the mitochondrial DNA abnormality. Diagnosis often requires either multiple blood draws or more often muscle biopsies. There have even been cases in which brain biopsies have been required to make the diagnosis. So certainly no one recommends screening large numbers of children for mitochondrial disorders.
As to whether children in the – among children who have autism that they have higher rates of mitochondrial disorders, again, I think that′s a hypothesis and there′s really remarkable little data to address that. I think that as we go forward and look at genetic studies on a larger scale of children with autism that certainly is one of the hypotheses that will be considered.
GLEN NOWAK: Thank you. Dr. Insel.
DR. THOMAS INSEL: Really, I have nothing to add. I think that says it all.
GLEN NOWAK: OK. We will take the next question.
OPERATOR: Thank you. Our next question comes from Mike Stobbe, you may ask your question and please state your affiliation.
MIKE STOBBE: Hi. Mike Stobbe with the Associated Press. Thanks for taking the question. First, I just wanted to ask about the mitochondrial disorders, is it always underlying? Or is it possible to introduce the mitochondrial disorder through some sort of environmental exposure?
GLEN NOWAK: We′ll ask Dr. Trevathan to answer that.
DR. ED TREVATHAN: I think that what we know based on the current literature and research is that at least when we′re talking about the mitochondrial diseases of childhood that cause neurological regressions. I′ll – if we limit the discussion to that group it seems that the mitochondrial abnormality is preexisting and preexist the environmental exposure, which then is really the source of increased biological stress that causes an increased demand for energy. I don′t really think that the current thinking is that the environmental exposure causes the mitochondrial function to be abnormal.
MIKE STOBBE: Do we have any studies or evidence on whether a vaccine can count as a stressor?
DR. ED TREVATHAN: You know, I would say that that has been raised as a hypothesis as to whether vaccines can cause stress that can lead to deterioration. I think we know that very high fevers from multiple causes can cause children mitochondrial disorders to regress.
And, we also know that a lot of different infections have been associated with regression. So we know of a lot of the different regression causes. Whether or not vaccines independent of another event such as high fevers, especially with a viral infection, for example, are causes of precipitating regression in children with mitochondrial disorders. I don′t think we really know that yet.
GLEN NOWAK: Is there anybody else that would like to address that question? OK. Next question, please.
OPERATOR: Thank you. And this question comes from Julie Rovner, you may ask your question, please state your affiliation.
JULIE ROVNER: Hi, this is Julie Rovner from National Public Radio. Thank you for taking my question. I know you can′t talk directly about the case in hand, but certainly there are those who are saying that this represent a concession by the government that vaccines cause ether autism or in this case mitochondrial disease.
Can you talk a little bit though about what we know about the science of what vaccines do and don′t cause in terms of autism and mitochondrial disease?
GLEN NOWAK: Sure. I′ll have Dr. Gerberding start.
DR. JULIE GERBERDING: Let me be very clear that government has made absolutely no statement about indicating that vaccines are a cause of autism. And that is a complete mischaracterization of the findings of the case and a complete mischaracterization of any of the science that we have at our disposal today. So, I think, we need to set the record straight on that.
With respect to the other I′ll let Dr. – you want to go here or go to Dr. Insel?
GLEN NOWAK: Yes, I guess the second part of your question we′ll have – do you want to restate the second part of your question to make sure we have the right person.
JULIE ROVNER: I wanted to know what the – what we know scientifically about any association between mitochondrial disease and vaccines.
GLEN NOWAK: OK. I guess Dr. Trevathan sort of answered that but I′ll have him …
JULIE ROVNER: I mean I know there have been study after study on autism and thimerosal and vaccines. Have there been any kinds of studies on mitochondrial disease and vaccines?
DR. ED TREVATHAN: Well, I don′t think we have any science that would lead us to believe that mitochondrial disorders are caused by vaccines. No I′m not aware of any science that would really suggest that and I′m not really sure that people that are real experts in the field would necessarily consider that to be a biologically plausible hypothesis. I don′t know if – Dr. Insel if you have any thoughts on that.
DR. THOMAS INSEL: I would defer to your judgment on that. The mechanism by which vaccines would cause mitochondrial damage would be a little difficult to imagine. It′s probably important in this discussion to clarify that what we′re talking about are mitochondrial disorders due to defects or changes in the mitochondrial genome. So these are changes at the DNA level.
There are lots of factors, thyroid, hormone and many others that effect mitochondrial function without changing the mitochondrial genome. The question here is when there′s an underlying mitochondrial genomic problem is there a greater variability to any kind of stress? And what Dr. Trevathan is saying is yes. That – when you have a genetic lesion in your mitochondrial DNA you′re likely to develop a whole range of problems due to environmental stressors.
GLEN NOWAK: Thank you. Next question, please.
OPERATOR: Our next question comes from Pete Williams, you may ask your question and please state your affiliation.
PETE WILLIAMS: Yes, it′s Pete – sorry – Pete Williams from NBC News. Is there any difference between saying that a patient has “Features of autism spectrum disorder,” and autism? In other words, based on your earlier statement that autism is, you know, a sort of range of symptoms. Is there any difference between saying a patient has “features of autism spectrum disorder” and has autism?
GLEN NOWAK: Dr. Insel, would you like to answer that question or address that question?
DR. THOMAS INSEL: Well, there can be. So what we often would say is it a person had Rett Syndrome or Fragile X disorder or tuberous sclerosis. These are genetic diseases that they can also develop features of autism. Now in those cases you know there′s a cause that could explain the autistic features.
Frequently, what people will say when there isn′t any cause that they can point to is that this is a child with autism or with autism spectrum disorder. Did that help to clarify the difference?
PETE WILLIAMS: Sure. And if I could just clarify the other point that Dr. Gerberding was just making. I take your point that the government has never said there was any connection here, but has the vaccine court ever awarded compensation in the past for parents of a children that got – that claimed autism resulted from a vaccine?
GLEN NOWAK: This is one, I think, probably that question is best directed to HRSA since they handle the vaccine compensation program. Next question.
OPERATOR: Thank you. Our next question comes from Denise Grady, you may ask your question, please state your affiliation.
DENISE GRADY: Denise Grady from the New York Times. When are these mitochondrial disorders generally first recognized or diagnosed in children? And then a second part to this question is, for children who have these disorders is there – should there be any different recommendation regarding vaccination than what is all ready made for kids who do not have these disorders?
GLEN NOWAK: I will have Dr. Trevathan handle this question.
DR. ED TREVATHAN: Well, in answering the question I should just emphasize that there are a large number of different mitochondrial disorders. The ones that are associated with severe neurological regression in children are usually diagnosed when children are toddlers or at least most often before school. There are a variety of different other mitochondrial disorders that sometimes present later in life like in adolescence or something like that when they′re going through puberty, for example.
But the vast majority of children that have this sever neurological deterioration and regression from the mitochondrial disorders most of those children are preschool children or toddlers.
And in terms of the vaccine recommendations, I don′t believe that there′s any official recommendation that′s different for children with mitochondrial disorders. We – their physicians are often asked to use judgment when evaluating these sorts of children and really looking at the individual risk benefit for that particular child.
I know that many pediatric neurologists do recommend vaccinating children with mitochondrial disorders in large part because many of the infections that we immunize children against protect children from ((inaudible)) are infections that are known to be associated with severe regression in children who have mitochondrial disorders.
GLEN NOWAK: Thank you. We′ve got time for two more questions. I′ll take another question.
OPERATOR: Thank you. The next question comes from Nancy Shute, you may ask your question. And please state your affiliation.
NANCY SHUTE: Yes, Nancy Shute, U.S. News and World Report. Do you have information – you said earlier that HRSA was the place to go for information on compensation for vaccine related autism like symptoms. Do you have any other comment on that?
GLEN NOWAK: No. I mean I believe – I don′t believe there is a – I don′t believe there ever has been but HRSA would be the place to go to ask that question.
NANCY SHUTE: OK, thank you.
GLEN NOWAK: One last question.
OPERATOR: Thank you. Our next question comes from Mike Stobbe, you may ask your question, and please state your affiliation.
MIKE STOBBE: Thanks. Mike Stobbe again from the AP. I don′t know if you can all make this clear, but we′re getting like two messages from the government. The information that you′re providing in this call is very helpful. But we also have information that the compensation program conceded a payment to this girl apparently acknowledging that her symptoms were worse – her situation was worse after the vaccine was given. And you can see it′s almost like two different messages, anything you can say to help clarify this, as we the media try to sort this out.
DR. JULIE GERBERDING: At this moment, Mike, as we said, we are not able to discuss what we know about this case. But let me just reassure you that there is no inconsistency. There′s nothing here that would suggest that the government is making any statements about the relationship between vaccination and autism. This is a really very special situation in a child who was genetically predisposed. The child had many other circumstances and stressors in this period of time. And I think we just need to have a chance to get the full facts of the information out and I believe you would conclude as we have that this does not represent anything other than a very special situation and a very sad situation for the family of the effected child.
GLEN NOWAK: Well thank you. Thank you for calling in this afternoon. And I look forward to talking to you in the future. And with that that concludes this telebriefing.
OPERATOR: Thank you. And that does conclude today′s call. We thank you for your participation. At this time, you may disconnect your lines.
- Historical Document: March 6, 2008
- Content source: Office of the Associate Director for Communication
- Notice: Linking to a non-federal site does not constitute an endorsement by HHS, CDC or any of its employees of the sponsors or the information and products presented on the site.
Get e-mail updates
To receive e-mail updates about this page, enter your
- Centers for Disease Control and Prevention
1600 Clifton Rd
Atlanta, GA 30333
TTY: (888) 232-6348
- Contact CDC-INFO