MMR and autism

T D Laing RTLaing at Monarch.net
Thu Oct 14 20:59:23 EST 1999


In article <38055A16.88C40FC0 at cyllene.uwa.edu.au>, Alec Redwood
<aredwood at cyllene.uwa.edu.au> wrote:

>     Hi I have been asked by a concerned mother if there is any link
> between the MMR vaccine and autism.  She has been advised by her GP not
> to have the MMR because these so called.  Having a look at some of the
> literature the jury appears to be still out.  So to any with an interest
> in vaccine development etc....is there a link, however tenuous?

If MMR vaccine were indeed causative for autism, one would expect to see
a
dramatic jump in autism rates soon after introduction of the MMR
vaccine.
A couple of studies have been done in the UK showing that there was no
such
increase in rates of autism after the MMR vaccine was introduced in 1988
(one abstract below):

Lancet 1999 Jun 12;353(9169):2026-9

Autism and measles, mumps, and rubella vaccine: no epidemiological
evidence
for a causal association.

Taylor B, Miller E, Farrington CP, Petropoulos MC, Favot-Mayaud I, Li J,
Waight PA

Department of Community Child Health, Royal Free and University College
Medical School, University College London, UK.

BACKGROUND: We undertook an epidemiological study to investigate whether
measles, mumps, and rubella (MMR) vaccine may be causally associated
with
autism. METHODS: Children with autism born since 1979 were identified
from
special needs/disability registers and special schools in eight North
Thames health districts, UK. Information from clinical records was
linked to immunisation data held on the child health computing system.
We looked for evidence of a change in trend in incidence or age at
diagnosis associated with the introduction of MMR vaccination to the UK
in 1988. Clustering of onsets within defined postvaccination periods was
investigated by the case-series method.
FINDINGS: We identified 498 cases of autism (261 of core autism, 166 of
atypical autism, and 71 of Asperger's syndrome). In 293 cases the
diagnosis could be confirmed by the criteria of the International
Classification of Diseases,
tenth revision (ICD10: 214 [82%] core autism, 52 [31%] atypical autism,
27 [38%]
Asperger's syndrome). There was a steady increase in cases by year of
birth
with no sudden "step-up" or change in the trend line after the
introduction of MMR
vaccination. There was no difference in age at diagnosis between the
cases
vaccinated before or after 18 months of age and those never vaccinated.
There was no temporal association between onset of autism within 1 or 2
years after
vaccination with MMR (relative incidence compared with control period
0.94 [95% CI 0.60-1.47] and 1.09 [0.79-1.52]). Developmental regression
was not
clustered in the months after vaccination (relative incidence within 2
months and 4 months after MMR vaccination 0.92 [0.38-2.21] and 1.00
[0.52-1.95]). No
significant temporal clustering for age at onset of parental concern was
seen for cases of core autism or atypical autism with the exception of a
single interval
within 6 months of MMR vaccination. This appeared to be an artifact
related to the
difficulty of defining precisely the onset of symptoms in this disorder.
INTERPRETATION: Our analyses do not support a causal association between
MMR vaccine and autism. If such an association occurs, it is so rare
that it could not be identified in this large regional sample.

Comments:

       Comment in: Lancet 1999 Jun 12;353(9169):1987-8

PMID: 10376617, UI: 99303110

(Interestingly autism rates began increasing well before the
introduction
of the MMR vaccine.  The increase in rates may simply be due to better
recognition of the condition.)

Autism has a significant genetic component.  Its signs overtly manifest
themselves about the age children normally receive MMR (between 1-2
years
of age).  But actually there is much evidence to suggest that autistic
behavior is observable before that, even from birth, from studies of
videotapes of young infants who later were diagnosed with autism:

J Autism Dev Disord 1994 Jun;24(3):247-57

Early recognition of children with autism: a study of first birthday
home
videotapes.

Osterling J, Dawson G

Department of Psychology, University of Washington, Seattle 98195.

Coded home videotapes of 11 autistic and 11 normally developing
children's
first year birthday parties for social, affective, joint attention, and
communicative behaviors and for specific autistic symptoms. Autistic
children displayed significantly fewer social and joint attention
behaviors and significantly more autistic symptoms. In combination, four
behaviors correctly classified 10 of 11 autistic children and 10 of 11
normal children. These behaviors consisted of pointing, showing objects,
looking at others, and orienting to name.

PMID: 8050980, UI: 94327431

J Am Acad Child Adolesc Psychiatry 1993 May;32(3):617-26

Blind ratings of early symptoms of autism based upon family home movies.

Adrien JL, Lenoir P, Martineau J, Perrot A, Hameury L, Larmande C,
Sauvage D

Departement de Neurophysiologie et de Psychopathologie du Developpement,
University of Tours, France.

Ratings of family home movies of 12 infants (0 to 2 years old) who were
later diagnosed as autistic and 12 normal infants were performed by two
diagnosis-blind psychiatrists with Infant Behavior Summarized Evaluation
scale. The objective was to identify early symptoms of autism and their
intensity and
frequency before and after 1 year of age. Several pathological types of
behavior related to socialization, communication, motility, and
attention were noted during the first year of infant life and
differentiated autistic and normal groups. These same differentiating
behaviors, observed again in the second year, were more
intense and associated with other pathological types of behavior, in
particular, gaze avoidance, hypoactivity, and absence of emotional
expressions. Analysis of
the evolution of behavioral pathology in autistic children as a group
during the 2 first years of life confirms the persistence of and the
increase in some types of
abnormality related to socialization, communication, motility, and
attention functions. The limitations and values of this study concerning
the early
identification of autistic symptoms and functional impairments from home
movies for diagnosis and establishing individualized treatment program
are discussed.

PMID: 7684363, UI: 93266489

There is such a range of behavior in infants that we call "normal" that
it
is possible some apparently "normal" infants are actually autistic, but
it
is not until they reach the age where language skills are expected to
develop that they are recognized as such.  It's about the same time that
MMR vaccine is usually given.  So some parents are likely to make that
association, because of the very understandable need to blame something,
whether it be causative or not.

On the flip side, measles, mumps and rubella are now rather uncommon
because of vaccination; many people have simply not seen any cases, so
may
not understand how dangerous these diseases can be.  You can bet though,
once vaccination stops, there will be epidemics again.

Hope this helps,

T.



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