Sorry, Michele Bachmann. Boys and young men should be routinely vaccinated against the human papillomavirus, or HPV, according to new recommendations from the Centers for Disease Control (CDC). About 18,000 HPV-related cancers strike American women each year compared to 7,000 cases among men. Previously, only girls and young women were urged to get the vaccine. Now, in a bid to lower cancer rates, injections of the vaccine Gardasil are recommended as "routine" — the CDC's highest ranking — for boys as young as 11, too. Here, a guide:

What is HPV exactly?
The most common sexually transmitted infection in the United States, according to the CDC. At least 50 percent of sexually active Americans will contract genital HPV in their lifetimes, often unwittingly because symptoms aren't always overt. What makes HPV particularly dangerous is that it sometimes leads to "cancers of the vagina, vulva, anus, penis and back of throat, as well as genital warts," says Liz Szabo at USA Today. Only 1.5 percent of American boys are being vaccinated against HPV today.

What makes the vaccine so controversial?
The fact that kids as young as 11 and 12 are being vaccinated against an infection that's contracted through sexual activity. Now, "that controversy is likely to intensify... since many of the cancers in [males] result from homosexual sex," says Gardiner Harris of The New York Times. The vaccine itself has been "a source of contention among Republican presidential candidates" this fall. Texas Gov. Rick Perry came under intense fire at a GOP debate because he briefly required that 12-year-old girls in his state be vaccinated, which didn't sit well with many anti-government conservatives. Bachmann, for one, even "falsely suggested that the vaccine causes mental retardation."

Are there downsides to the shots?
Potential side effects include pain and swelling at the injection site, headache, and fever. The Gardasil vaccine is also relatively expensive — around $100 for each of the three recommended shots (and not all insurance plans cover the procedure). But the panel says that the HPV vaccine makes "economic sense, assuming the immunizations cut the transmission of HPV and decrease the development of genital warts."

Sources: NPRNY TimesUSA Today