Brian, I'm copying below one of the articles I read, which references a FDA study. I'll be sure to include sources in the future. My comment was in reference to Samkl's question about vaccinating those who have already been infected with HPV, which appears to be a more complicated question that vaccinating those who have not.

I wish there was an easy, 100% risk free decision...but such things really don't exist. As the parents of one child who has already had a severe vaccine reaction (MMR, epilepsy), we know first hand the heartache associated with trying to do something to help your child, only to have it result in severe injury. Then on the other side, as I watch my husband fight his way through this horrible cancer, the thought that our sons could end up in the same position 20, 30, 40 years from now is unbearable. We are leaning towards immunizing...but we are doing so know full and well there are real risks involved. If you are going to immunize, it seems better to do so before HPV exposure/infection.

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