You can tell your daughters whatever you want. We know that a good number of them, regardless of their parents values, convictions, and guidance, will be sexually adventurous as they grow older.
I know there are no guarantees in life, however the message that parents send their kids is an extremely important factor in their behavior. The culture bombards them everyday with the message that promiscuity is OK. It's a battle where we as parents are greatly outnumbered. I choose not to surrender.
I have an 11 year old daughter. She probably knows nothing about this vaccine. What reason do you give her if she asks why she needs this vaccine? There is no coherent answer you can give which does not carry with it the condoning of the behavior. We don't need another "here's a condom, don't use it type message" - they don't work.
Further, HPV isn't the sole horrific consequence of promiscuous behavior. This vaccine is being marketed as a panacea, and young minds will get the impression that they are "safe" when they are not.
The bottom line is "safe sex" is a myth. I once asked the Executive Director" of a pregnancy care center what percentage of their pregnant clients were taking birth control and she said "2/3"
Please don't surrender to the culture. You may think you are protecting your children but you really aren't. They may not get HPV, but there's still pregnancy, abortion and about 27 other STD'S