Can Vaccines Cause Autism?

Why has the incidence of autism increased? Do you think vaccines relate to this?

There really is not a good hypothesis right now to explain that increase. I think many parents have been concerned that vaccines may cause autism. At this point there is not any good evidence that shows vaccines result in autism. That does not mean that there could not be children where that happened, but you can not explain the increase in autism by vaccine rates because, in fact, they have not occurred at the same time. So, it is not that when the numbers started to increase in autism was the same time when kids started getting vaccines. What is coincidental is that the timing of when autism begins to be noticed in children tends to be the beginning of that second year of life, and there are some kids with autism who really seem to lose skills during that time, and we do not know why. That does occur in the same period when kids get vaccinated, but as far as we can tell it is not causal. It is not that one causes the other, it is just that they both happen at about the same time.

Do you ever see a child younger than 2 diagnosed with autism?

More and more we are seeing kids who are referred at early ages. That is one of the things we study here, which is how early we can make a diagnosis. Sometimes in 1-year-olds, they really do look and act autistic. By that, I mean they have the same social behaviors, they have odd interests, they have unusual movements, but there are also kids whose parents are concerned early on even though they do not look autistic. Some of them look more autistic as they get older, and some of them do not. One of the big scientific questions right now in the United States and Europe is what are the signs that really mean something in those little kids, and what are the signs that there is no need to worry. Most of the kids I have met where parents have been worried if they might have autism at very early ages are the siblings of kids who have autism, and there have been a number of times where parents have said, “I think this is autism again when I saw the child at first.” I could not see it, and then in fact, the parents were right. So, I think there is a lot to be learned about those earliest signs, and there are also a number of parents who have had other kids who will swear that their child really was quite normal in that first year of life, and I think we believe them, but we do not know how that becomes autism.

Do you have any idea what some of those early signs of autism are?

Yes. Probably one of the earliest signs is a child who seems to understand some language, but does not respond to his or her name. They just do not seem to understand when you are calling them that that is why you are making that sound. Also, kids with autism when they are young do not seem to respond as well to the idea of shared attention. So if I started looking off to the corner over here, you would probably start looking there too wondering why am I looking over there, and that is something that is much harder for kids with autism to do. That is something that typical babies can do usually in the beginning of the second year of life. Also, many kids with autism do not point to draw people’s attention to things. They do not point out things like a cow or a fire engine or the moon, and they do not take that social initiative even though they may go to their parents for help. Those are the predominant things that you look for, but I do think if families are worried it is really important for them to find someone who knows a lot about autism in very young kids and then work with them to try to figure out what you could be doing about it to get the child started on therapy.

Also, I think it is hard that kids at that age are so cute and so engaging, and people have this conception of autism as this horrible disorder that means you are totally aloof and are in a corner banging your head. When in reality, the little kids may be very happy and smile a lot and are just as cute as can be, but they do not participate in social interaction the same way.

Autism Disorders

Is there the chance that some of these disorders were completely different disorders and not autism?

Yes, because autism is defined completely by behavior at this point. There are hints about the biological causes of it, and the assumption is that it is something biological, but there is no clear biological marker. The most consistent finding that has to do with biology is that kids with autism have big heads more often then you would expect, but a lot of other people have big heads. It is not a very specific finding. So it really may be that autism is like a fever, where you can have a fever for a lot of different reasons and is the final common pathway of a lot of different things.

Is fragile X considered to fit in the grouping of autism?

Fragile X is separate in the sense that in fragile X, we know exactly where the gene is that causes the disorder, but many kids with fragile X have symptoms that fall within the autistic spectrum. So if you were defining them purely by behavior, some of them would have autism. However, if you are defining autism as things that we do not know the cause of then fragile X would be excluded because we do know what it is that initiates it. We do not know how to treat it very well yet, but we know where that gene is.

Are children with autism tested for fragile X?

Lord: Almost always. I think that is one of the first things that most physicians do.

What is the incidence of autism?

Autism was conceived as a very specific disorder almost always associated with mental retardation, but quite severe. The estimates there were four or five per 10,000 kids, so maybe one in 2,000 kids, had the disorder, but what has happened is that the conceptualization of the disorder has gotten quite a bit broader to encompass kids who have specific social deficits. It includes a general pattern, but is not necessarily mental retardation, and so there are more of those kids. We do not know if having a broader definition accounts completely for this rise in number, or whether there actually are more kids with autism or autism-spectrum disorders. Now, autism is seen much more as a spectrum rather than just one single disorder. Part of the confusion is who exactly is in that spectrum. Where do you draw the line? So, that has meant that their estimates are anywhere from one in 100 to one in 200, which I think is the most commonly accepted prevalence rate.