The black plague burning itself out makes sense, but that would not account for it completely. Correct me if I'm wrong, but I don't believe there has been a case of the bubonic plague for quite a long time now. Living conditions in Europe got better and now conditions are good enough that sicknesses which used to be a problem are now only minor issues.
I don't know what your point is here. What, that girls who have sex with more than one partner are dirty little sluts who deserve what they get? Does that hold for boys, as well? Because men can get colon cancer from HPV, which is why Gardasil is going through trials on men, too.
You play with fire, you get burned. No, I'm not saying that I want people to get STD's, but that's what happens. I don't have much sympathy for those people, though I wish them full recovery if possible. Yes, that holds for boys, too.
I don't think anyone should be going to vaccines for safety when they are the ones putting themselves in danger. A person should put himself out of danger as much as possible and if it's still a horrible epidemic that's going to kill you, then vaccines may become important. I know of no such epidemics in the United States.
You do realize that nearly 80-90% of the population is infected with some form of HPV, correct? And you can spread it simply from touching somone (though the chance is minimal)? If you've had sex with someone, anyone, you can contract it. If you kiss someone, you can contract it. If you shake their hand, you can contract it. HPV is like herpes--you can have it and be a virgin, and the method of infection, expression, and rate of clearance from the body is very poorly understood.
I don't believe that happens very much, though of course, it can. Clearly a good deal of that 80-90% is some relatively benign form of HPV, otherwise we'd pretty much all be diagnosed with an STD.
As for your rape question, I would sooner train her in the use of a gun and make sure she carries one with her. Guns provide protection from HIV, AIDS, HPV, herpes, loss of life, etc... while the vaccine only covers HPV and does not prevent the rape from occurring. But wait, the government doesn't let minors have guns, does it? As a matter of fact, what with all the red tape, most law abiding young women aren't going to have anything for self defense when they really need protection.
Anyhow, possibility of rape isn't necessarily a reason for getting the vaccine. Like I said, there are a lot of other dangers in that situation that aren't being dealt with, and the two risks of vaccine and rape have to be weighed.
Essentially what I've been trying to say this whole time is:
To prevent disease:
1. Avoid people and places likely to have diseases. It's common sense that a tuberculosis-filled town is not a good place for someone who wants to avoid tuberculosis. Public school is a nation-wide violation of this.
2. Proper hygiene. This ranges from basic (washing your hands) to large-scale (plumbing, sewer systems).
3. Vaccines if there is still a need. If the first two rules are kept, then rates of disease would fall immensely. From these rates, you should determine what diseases are still a problem and merit the risk of taking a vaccine.
Sometimes the first two rules might be broken for good reason. In such cases, risk begins to tilt more towards disease than vaccine. Examples would be a doctor who has to be around sick people or charity workers in an undeveloped country. However, these rules should not be broken without good reason and if they are, then more people get sick and more people take vaccines while not separating themselves from the root problem.