BACKGROUND:
Since the time of Voltaire, anti-vaccinationist sentiment has been largely philosophical and relgious. In recent decades however, it has shifted to science-based concern about vaccine safety. The science that supports the most prevalent current safety concern, the alleged association between MMR and thimerosal-containing-vaccines and autism, is seriously defective. Nevertheless, the association is being effectively marketed, especially via the Internet alternative medicine and anti-vaccination sites. MMR coverage rates in Britain have declined precipitously due in large part to the efforts of anti-vaccination activist Dr. Andrew Wakefield who is now based in Florida. One wonders what affect his and other dissenting voices are having in the US.

OBJECTIVE:
To review current medical and anti-vaccinationist literature. To survey Wisconsin primary care pediatricians relative to vaccination refusal in their practices. To tabulate school-age and two-year-old vaccination coverage and reasons for refusal in Wisconsin 1990 to present.

METHOD:
Dissenting scientific articles by Dr. Wakefied and Dr. Geier, and anti-vaccinationist thought published in books, counter-culture magazines and on the Internet, and British, Danish and US rebuttals published in mainstream medical journals were reviewed. Three-hundred primary care pediatricians in Wisconsin were mailed a brief questionaire asking rates of vaccination refusal by vaccine with reasons given by parents in their practices. Wisconsin Division of Public Health statistics for vaccination coverage and waiver requests for school-age children were analyzed for years 1990 to 2003. CDC National Immunization Survey data for MMR coverage at 24 months were analyzed for Wisconsin 1995-2003.

RESULT:
Most commonly refused vaccinations are varicella and MMR. Most common concern is safety/autism. Religious waivers requested steady at 0.1%. Personal conviction waivers have increased 371% (0.7% to 2.7%) MMR coverage for 24 month olds has significantly increased over time (90% to 94%/9years; P=0.001)

CONCLUSION:
To date, anti-vaccinationists have not made a significant impact on vaccine coverage in Wisconsin. On the other hand, the rise of personal conviction waivers shows the increasing inclination of parents to go against medical advice. This trend is cause for concern.

LEARNING OBJECTIVES:
To understand threat of anti-vaccinationists to childhood vaccine coverage.