title: Parental vaccine refusal in Wisconsin: a case-control study.
abstract: BACKGROUND
  Successful immunization programs have diminished parental fear of diseases and increased fear of vaccines. Children with nonmedical exemptions to school immunization requirements are at increased risk of acquiring and transmitting disease. We explored differences in vaccine attitudes, beliefs, and information sources among parents of exempt and vaccinated children.
  
  
  METHODS
  Self-administered surveys were mailed to 780 parents of children with nonmedical exemptions (cases) and 1491 parents of fully-vaccinated children (controls).
  
  
  RESULTS
  Vaccines most often refused by exempt children were varicella (49%) and hepatitis B (30%). The most common reason for claiming exemptions was vaccine might cause harm (57%). Parents of vaccinated children were less likely than parents of exempt children to report concern about vaccine safety, question the need for immunization, and oppose immunization requirements. Nearly 25% of parents of vaccinated children reported that children get more immunizations than are good for them and 34% expressed concern that children's immune systems could be weakened by too many immunizations. Both groups received information from health care professionals; parents of exempt children were more likely to also consult other sources.
  
  
  CONCLUSIONS
  Our findings support the need for improved methods to communicate vaccine safety information. Further studies to explore vaccine safety concerns among parents are needed.
authors.affiliation: Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA.
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Salmon
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Sotir
authors.forename: William K
authors.initials: WK
authors.lastname: Pan
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Berg
authors.forename: Saad B
authors.initials: SB
authors.lastname: Omer
authors.forename: Shannon
authors.initials: S
authors.lastname: Stokley
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Hopfensperger
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Davis
authors.forename: Neal A
authors.initials: NA
authors.lastname: Halsey