Objective: The purpose of this work was to assess the association between media coverage of the MMR-autism controversy and MMR immunization in the United States.
Methods: The public-use files of the National Immunization Survey were used to estimate annual MMR coverage from 1995 to 2004. The primary outcome was selective measles-mumps-rubella nonreceipt, that is, those children who received all childhood immunizations except MMR. Media coverage was measured by using LexisNexis, a comprehensive database of national and local news media. Factors associated with MMR nonreceipt were identified by using a logistic regression model.
Results: Selective MMR nonreceipt, occurring in as few as 0.77% of children in the 1995 cohort, rose to 2.1% in the 2000 National Immunization Survey. Children included in the 2000 National Immunization Survey were born when the putative link between MMR and autism surfaced in the medical literature but before any significant media attention occurred. Selective nonreceipt was more prevalent in private practices and unrelated to family characteristics. MMR nonreceipt returned to baseline before sustained media coverage of the MMR-autism story began.
Conclusions: There was a significant increase in selective MMR nonreceipt that was temporally associated with the publication of the original scientific literature, suggesting a link between MMR and autism, which preceded media coverage of the MMR-autism controversy. This finding suggests a limited influence of mainstream media on MMR immunization in the United States.