Do they? Don't they?
- Vaccine Affect
- May 2
- 2 min read
Autism and measles, mumps, and rubella vaccine: no epidemiological evidence for a causal association
Taylor, Miller, Farrington et al.
The Lancet, Volume 353, Issue 9169, 2026 - 2029
Researchers investigated whether measles, mumps, and rubella (MMR) vaccine may be causally associated with autism.
They identified 498 children with autism born since 1979 were from special needs/disability registers and special schools in eight London health districts.
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.
"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."
Andrew Wakefield responds
“A case-series analysis is unlikely to identify a relation between exposure and disease, in which the onset is insidious and in which, very often, there is diagnostic delay.”
Taylor et al “identified a statistically significant excess risk by 6 months after MMR, which they dismiss, post hoc, as indicating parental recall bias. Had this been the case it should have been seen in both of their vaccine groups—those receiving MMR and those receiving any measles-containing vaccine. The excess risk was seen only in the MMR group; this is a fundamental flaw.”
Wakefield mentions “failure to declare the fact of an MMR catch-up campaign that was initiated in 1988 with the introduction of this vaccine. This campaign was targeted at children, whatever their age.”
On the basis of Taylor and colleagues' inclusion criteria, and taking account of the catch-up campaign, then those first birth cohorts who actually received MMR (circa 1986) were precisely those in whom a doubling of the numbers of cases of autism were seen. Thereafter these numbers continue to increase strikingly.
These data expose the danger of not only setting out to prove, rather than to test, hypotheses but also presenting the data whether they are supportive or not.
