MMR cannot be exonerated without explaining increased incidence of autism
EDITORKaye et al observe that the rise in the incidence of autism cannot be attributed to measles, mumps, and rubella (MMR) vaccine because vaccination remained consistently above 90% in the period studied.1
I have several issues with their study:
(1) The cohort of children chosen was born during 1988-93. MMR was introduced in the United Kingdom in 1988 and an uptake of 90-95% is unlikely to have been achieved from the first year.
(2) Kaye et al effectively excluded children born before 1988 who may have been vaccinated in or after 1988.
(3) The 114 boys selected were observed until the age of 71 months. Many of them could have succumbed after the second MMR vaccination (booster), which is given between the ages of 4 and 5 years. The study did not mention how many children received two MMR vaccinations.
(4) MMR vaccine was previously given alone at 15 months or later. Then the age was lowered to 12-14 months and other vaccines were administered concomitantly, increasing the immune antigenic insult at a younger more susceptible age and effectively increasing the incidence of autism.
(5) The restriction of the cases in the main analysis to 114 boys is of concern. A breakdown of the 290 children in the 1990-9 birth cohorts by sex and year of birth would have been informative. A larger proportion of girls among the 176 cases excluded might have been relevant to the completeness of the autism figures.
(6) The fact that neither DSM-IV nor IC-10 was systematically used in the United Kingdom creates further doubts about the significance of the findings.
Professor Brent Taylor in the Lancet (1999;353:2026-9) and now Kaye et al have clearly documented the epidemic of autism in the United Kingdom. Before 1988 the incidence of autism was 1 in 10 000; after 1988the year MMR was introducedit leapt to 8 in 10 000. By 1993 it was 29 in 10 000.
Kaye et al cannot exonerate MMR without offering a reasonable explanation for the increase.
Until safety studies on MMR are independent of drug companies and are large scale and
comprehensive, and until researchers review with parents the documented adverse
reactions of bowel disease and autism, the triple jab remains suspect.
F Edward Yazbak
TL Autism Research, 70 Viewcrest Drive, Falmouth, MA 02540, USA
|1.||Kaye JA, del Mar Melero-Montes M. Mumps, measles, and rubella vaccine and
the incidence of autism recorded by general practitioners: a time trend analysis. BMJ
2001; 322: 460-463