HPV is one of the few viruses that can be transmitted from sexual contact that is not necessarily intercourse, and is especially easy to spread. Many teens who would not risk actual intercourse may still expose themselves other genital contact activities. A condom may not cover all parts of the genitals that could spread the virus as well. I think there's lots of reasons (especially emotional) to wait to have sex until one is older and in a stable relationship, I personally was nearly 19, my best friend was 23 (rare now days) and I've always told my children that waiting was a positive thing for myself and others because it gave us time to grow and not complicate our lives before being ready. However, all the talk in the world is not a guarantee, I've worked with pregnant teens and some of them still had pretty open and positive communication with their parents and they got pregnant anyhow, and there are many not pregnant sexually active teens out there, too. My sister in law, who had only one sexual partner previous to her husband, was dealing with a case of cervical cancer at only the age of 21, discovered during a Pap test run when she first found she was pregnant with her first child. Not a very nice way to start motherhood, dealing with cancer treatments immediately after the baby, and one recurrence later as well. Needless to say, she is very open with her daughters about the safety of their sexual choices, and both my nieces (they are 13 and 12) had the vaccine. Considering that even a my daughter's husband to be could carry HPV and she could catch it even if she remains a virgin until she is married, I'm planning for my own daughter to have it as well. It would be nice if all potential mates were virgins, but is that really the only or main criteria you would want for your daughter's future husband? That can eliminate lots of great people that just made different choices. Now as to the effectiveness of the vaccine, it's pretty new, and I understand being cautious with something relatively untried as to results vs risk, and I understand that some people would see the risk as too great. Determining your comfort level is personal choice. But I don't think making the decision based on what you think the likelihood of your daughter having intercourse is the way to go, so many things don't happen according to plan, and I'd always want to be prepared for the worst case scenario.