have been the source of the most clinical and political controversy. The vaccine also was initially approved for females, he points out, and vaccination rates for men are still low. "We thought we should focus on a population that is most likely to get vaccinated, but for some reason they are not getting vaccinated," he says.





Jena says the study, like many about HPV, focused on females because their vaccination rates

Discussion about HPV vaccination can leave men out of the picture, even though 9,300 of males in the U.S. are affected by cancers caused by HPV. For men, HPV can lead to cancers of the anus and penis. It can also cause cancer in the back of the throat, including the base of the tongue and tonsils. The vaccine Gardasil could prevent many of the cancers in men, but the push widely has been for women – though some say there has been a shift in recent years. Vaccination rates for males climbed from 20.8 percent in 2012 to 34.6 percent in 2013, according to the CDC.

There are concerns about what administering the vaccine could mean to young people. Part of the concern is around the age that the CDC recommends the vaccine. For both boys and girls, the agency has recommended since 2011 that children receive the three-part vaccine at age 11 or 12. The agency has said that doing so would allow the immune system to build before teens become sexually active.

In a national survey of pediatricians, 60 percent said they thought parents would be concerned that HPV vaccination would promote unsafe sexual behavior, and 11 percent of pediatricians themselves reported they were concerned about this.

CDC says that not having sex is the only sure way to avoid HPV entirely – though condoms can reduce the likelihood of transmission. When combining vaccines with screening efforts such as Pap smears or HPV tests, CDC estimates that as many as 93 percent of cervical cancers could be prevented.