Human papillomavirus vaccine coverage/Author's reply

In the USA, the primary method of mandating childhood vaccination is making enrolment in public schools conditional on proof of vaccination. 24 states and the District of Columbia have proposed legislation to mandate vaccination against human papillomavirus (HPV).1 To date, only Virginia and the District of Columbia have enacted these requirements.1 These requirements went into effect for the 2009-10 school year.2,3 Both jurisdictions allow parents to opt out of the requirement for any reason. Since our analysis did not include data from the District of Columbia and used data collected in 2008, our findings should not be affected by these policies.