This document summarizes key scientific studies that have found no link between the MMR vaccine and autism, or the preservative thimerosal and autism. It discusses common fallacies and biases that undermine the conclusions of epidemiological research. It also examines how certain groups miscast the debate and how the media can promote misleading claims not supported by evidence.

1. Communicating Science to the Public Paul A. Offit, MD The Children’s Hospital of Philadelphia The University of Pennsylvania School of Medicine

2. MMR-Autism: Scientific Studies I Taylor, B, et al. Lancet 1999;351:2026-29 Dales L, et al. JAMA 2001;285:1183-85 Kaye JA, et al. Brit Med J 2001;322:460-3 Madsen KM, et al. N Engl J Med 2002;347:1477-82 Peltola H, et al. Lancet 1998;351:1327-8.

3. MMR-Autism: Scientific Studies II Makela A, et al. Pediatrics 2002;110:957-63 DeStefano R, et al. Pediatrics 2004;113:259-66 Farrington CP, et al. Vaccine 2001;19:3632-5 Fombonne E, et al. Pediatrics 2001;108:e58 Taylor, B, et al. British Med J 2002;324:393-6

4. Thimerosal-Autism: Scientific studies Hviid A, et al. JAMA 2003;290:1763-66 Andrews N, et al. Pediatrics 2004;114:584-91 Herron J. Pediatrics 2004;114:577-83 Verstraeten T, et al. Pediatrics 2003;112:1039-48 Barbaresi W, et al. Arc Ped Ado Med 2005;159:37-44 Schecter R, et al. Arch Gen Psychiatry 2008;65:19-24

5. Defeating Epidemiology

6. The fallacy of balance

11. Epidemiological studies cannot detect rare events

12. “ Vaccines might cause autism in a small group of genetically susceptible individuals.”

13. Power of epidemiological studies Paralysis (GBS) and swine flu vaccine Intestinal blockage and rotavirus vaccine Low platelets and measles vaccine Omnibus Autism Proceeding

14. Epidemiological studies don’t prove anything

15. Epidemiological studies and proof Flying like Superman WMD in Iraq Cigarette smoking and lung cancer

16. Anecdote trumps epidemiology

18. The power of box “a” Disease No disease Vaccine a b No vaccine c d Risk in “vaccine” group = a /a + b Risk in “no vaccine” group c/ c + d

19. Cultural Biases

20. The media defends the weak against the powerful

23. Players in vaccine-autism controversy If you care about children with autism, you support the notion that vaccines are the cause. Lawyers, politicians, fringe scientists, and journalists care. Doctors, public health officials, mainstream scientists and pharmaceutical companies don’t care.

24. Players in autism controversy are miscast Doctors and scientists who oppose notion that vaccines cause autism are standing up for the little guy Those who claim that vaccines cause autism hurt children by providing false hope, proffering dangerous therapies, and diverting limited resources

25. The media loves mavericks

30. “ While Galileo was a rebel, not all rebels are Galileo.” Michael Fitzpatrick

31. The media falls into the single-study trap

32. Wakefield, A.J., et al. Lancet 351: 637-641, 1998.

34. The media doesn’t understand science

35. What Science Isn’t Science isn’t scientists or scientific bodies or accumulated knowledge Science is a way of thinking about or approaching a problem Although scientists get it wrong all the time, science is enormously self-correcting; but fluidity of science can be disconcerting

36. Explaining cause and effect

37. The Lay of the Land Belief Percent of population Astrology 50 ESP 46 Witches 19 Aliens already landed 22 Commune with dead 42 Ghosts 35

38. Conflicts of interest

39. Ad hominem attacks If you don’t have the data, discredit the messenger Appeal to personal considerations rather than logic or reason CDC, AAP, individuals under fire

40. Easy appeal to toxic, environmental hell

46. Easy to scare people; harder to unscare them

48. Poor understanding of risk Scared of pandemic flu, but not epidemic flu; of radon, but not strokes and heart attacks; of dioxin, but not French fries; of plane travel, but not car travel; of MMR vaccine, but not measles; and of thimerosal-containing influenza vaccine, but not influenza.