HPV vaccine

The HPV vaccine protects against the human papillomavirus, or HPV for short. Its job is to block infection with the types of this virus that cause most cases of cervical cancer, which is cancer of the cervix, the lower part of the uterus that opens into the vagina. HPV comes in several types, like members of the same family, and the vaccine is designed to keep those particular types out.

Timing is what matters here. Almost everyone runs into some type of HPV during their lifetime, and sometimes the virus doesn't go away: it stays, it persists, and over time it can end up causing cancer. The vaccine is not a treatment; if cervical cancer is already there, the vaccine won't cure it. It works like an umbrella: the idea is to have it open before the rain starts. That's why it's recommended for adolescents: so the protection is in place before they're exposed to the virus.

And cervical cancer isn't the only cancer linked to HPV. HPV has also been linked to cancers of the vagina, the vulva (the outer part of the female genitals), the penis, the anus, the mouth, and the throat.