On October 25, 2011, an advisory panel for the Centers for Disease Control and Prevention (CDC) voted to recommend that the vaccine be given to boys ages 11–12. The panel's recommendation is intended to prevent genital warts and anal cancers in males, and possibly prevent head and neck cancer (though the vaccine's effectiveness against head and neck cancers has not yet been proven).[17] The Committee also made the vaccination recommendation for males 13 to 21 years who have not been vaccinated previously or who have not completed the three-dose series.[12][18]