State actions requiring adolescent girls to receive the human papillomavirus (HPV) vaccine created controversy following the vaccine's approval in 2006. Some health professionals worried that the controversy might dampen public supportfor those state policies and for other school immunizations in general. We fielded an experimental Internet survey to determine how controversy affects attitudes about vaccines. We discovered that public support for the HPV vaccine mandateswanes when the public is informed that the policies are controversial. However, the experimental survey also revealed that exposure to this policy controversy did not spill over and reduce public support for immunizations in general.