The notion that the MMR vaccine can trigger autism should have ceased
to be news long before this week’s widely reported study that shows it
to be unfounded. From a scientific point of view, the hypothesis has
never had much going for it.
The Andrew Wakefield paper that started the scare, published in
The Lancet in 1998, reported only the anecdotal suspicions of a few
parents who thought their children’s autism started when they were given
MMR. It had no controls, it presented no evidence, and it has been so
thoroughly discredited that the journal’s editor admits he should not
have run it.
Wakefield and two colleagues are now defending allegations of serious
professional misconduct from the General Medical Council.
Several epidemiological studies, which have compared the prevalence
of autism with MMR vaccination rates in Britain and abroad, have found
no association. Autism specialists, virologists and paediatricians have
long spoken with one voice: the triple jab is as safe as any other
Though the basis for alarm was flimsy, public concern has remained
strong. Confidence in the vaccine collapsed after Wakefield’s claims,
causing immunisation rates to fall to just 60 per cent in some areas.
Measles and mumps have accordingly made a comeback: there were about
1,000 cases of measles last year, compared with about 100 annually
before 2002, and cases of mumps now run into thousands instead of
hundreds. Only recently has the immunisation programme started to
There are lessons to be learnt from the saga. Health officials could
have presented complex information about risk more clearly, and Tony
Blair fed suspicion by refusing to say whether his son, Leo, had been
Parents should understand that, while a decision to vaccinate may
seem to have risks, these are far outweighed by the real risks of
leaving children unprotected. And journalists must learn to beware of
mavericks with scary theories but few facts. The way much of the media
stirred up the MMR panic did more damage than anybody besides Wakefield
himself. But it is time to draw a line under the affair. The evidence is
unambiguous, and this week’s study is important as it provides the
The strongest card of the vaccine’s opponents has been their claim to
have identified measles virus in the guts of some autistic children.
This, if true, would support their hypothesis – though they’ve been
loath to publish data, preferring announcements to newspapers. Strong
doubt has been cast on the methods by which the virus has been found,
but without detailed independent investigation of autistic children, the
issue remained unsettled.
The Wakefield camp has long called for such a study, and it has now
been done. The new research compared the blood of children with autism
with that of typically developing children and those with other learning
difficulties. All had had MMR.
If measles virus from the jab was causing autism, the effects should
have been visible in the autistic group, through the presence of either
persistent measles infection or measles antibodies in the blood. Yet
neither was found: the blood of the autistic children looked identical
to that of both control groups. The very study that the MMR critics
wanted has given the vaccine a clean bill of health. It has shot their
Several junk medicine columns have discussed MMR over the past few
years. It would be nice to think this will be the last one. Every ounce
of evidence that has been assembled on the issue, now covering every
possible approach, has reached the same conclusion: the vaccine does not
cause autism. It is surely time for those who have claimed otherwise to
apologise to the thousands of parents whose children have missed out on
important health protection as a result.