The doctor told her: "No, you're too old. It's too late for you. I'm sorry you didn't get it before."

Actually, I've learned, it's not quite that simple.

The issue comes down to a conflict between minding the health of populations vs. individuals. Federal regulators naturally care about setting policies that represent the most cost-effective way of protecting the overall population. And to be fair, the research has failed to provide evidence that recommending all older women get vaccinated against HPV fits that bill. Drug maker Merck's study of women 24-45 did show that the vaccine protects those with no prior exposure to the nastiest HPV strains, but taking the study participants as a whole -- an analogy for the overall population of women 24-45 -- not so much. So, the CDC recommends the vaccine just for females ages 11 to 26 and males ages 11 to 21.

That calculation is fine for the feds. But me -- I care about me.

HPV is a fantastically common sexually-transmitted disease, the most common one in the U.S. There are more than 40 strains that can infect the genitals, male and female. The CDC estimates that one in two people in this country will contract the virus at some point in their lives, while other estimates put it closer to four in five. The vast majority of infections cause no symptoms and go away on their own. But when they don't, a handful of strains can cause genital warts and cervical cancer, and less commonly, cancers of the vagina, vulva, penis and anus. HPV causes almost all of the 12,000 cases of cervical cancer diagnosed in the U.S. each year. The virus, also transmittable via oral sex, is driving rising rates of throat cancer, particularly among men. (That's right: oral sex can give you cancer. Yikes.)

Merck's Gardasil, the more widely used of two available HPV vaccines, protects against four of the most pernicious strains. On the market since 2006, the inoculation dramatically reduces teen girls' and young women's chances of getting the abnormal growths that lead to cancer. The vaccine prevents boys and men from passing on the virus to their sexual partners, and scientists expect it's also likely to protect them from throat cancer.

However, if you've already been exposed to the vaccine's four strains, it won't help you. It would seem logical to ask: "How do I know if I'm already exposed?" But the available blood test is pricey, unreliable and used only in research settings.

Among the 3,800 participants in Merck's study of older women, 67 percent showed no sign of prior exposure to the vaccine's HPV strains, and the others had mostly been exposed to only one. That sounds encouraging - except that as many as half of all HPV exposures won't show up on the blood test, so these rates are probably gross overestimates.

So, what's a health-conscious, not-so-young woman to do?