The HPV vaccine protects against most of the cancers caused by the human papillomavirus. HPV is a very common virus that spreads through sexual contact. Approximately 14 million people become infected each year. HPV can cause cancers of the anus, cervix, vagina, vulva, penis, mouth and throat. It is recommended that both boys and girls receive the vaccine at age 11 or 12 so they are protected before ever being exposed.