To the best of my knowledge the magisterium has never made a pronouncement regarding HPV vaccinations. What the Church teaches is that premarital and extramarital sex is wrong. It also teaches that contraception is wrong. But vaccinations?? There are a host of consequences from engaging in sexual intercourse. Some methods of protecting against those consequences are morally wrong and distributing them to teenage girls would be repugnant. Handing out condoms or birth control pills in the schools would definitely go against the Church's teaching. One does not use a condom if one intends to remain abstinent... the connection is immediate and obvious. A vaccine, however, has as it's primary purpose disease prevention. The efficacy of the vaccine, its potential side effects and its appropriateness for that particular population are all valid questions but dragging the magisterium into it is just irresponsible.
There is an ongoing controversy over the use of vaccines. It ranges from the rather simplistic notion that inoculating someone against smallpox is somehow interfering in God's plan to the use of forbidden technologies. Some vaccines are derived from tissue cultures obtained from aborted fetuses and the Church has specifically condemned these. Unless you can demonstrate that the HPV vaccination is derived from technology the Church has specifically forbidden you pretty much have to make the argument on its own merit.