evidence: A study of almost 3.5 million people confirmed that immunization against the human papillomavirus (HPV) lowers the chances of developing cancers caused by HPV. This includes head and neck cancer in men and boys and cervical cancer in women and girls. [...] The HPV vaccine was approved in the United States in 2006. Since then, many studies have shown that protection against HPV lowers the risk of cervical cancer. However, other cancers can be caused by HPV, including head and neck cancer, as well as cancers of the anus, penis, vulva, and vagina. This study compared cancer risk between people who received the HPV vaccine and those who did not. [...] The HPV vaccine protected women and girls against cervical cancer. There were 70 cases of cervical cancer among immunized women and girls. In comparison, there were 99 cases of cervical cancer among women and girls who were not immunized.