Just one-third of teen girls in the U.S. have received all three doses of the vaccine against the human papillomavirus (HPV), according to new research.


The study, presented at a meeting of the American Association for Cancer Research, also showed that most people for whom the HPV vaccine is relevant (meaning someone between ages 9 and 27, or someone who has an immediate family member in that age range) are unaware of its effectiveness.


"This uncertainty may influence decision-making about getting vaccinated, and it hinders our ability to reduce cervical cancer incidence and mortality and reduce disparities in cervical cancer," study researcher Kassandra I. Alcaraz, Ph.D., M.P.H., who is the director of health disparities research at the American Cancer Society, said in a statement.


That is troubling considering HPV is known to cause cervical, anal and vulvar cancers. Both of the currently available vaccines -- Cervarix[1] and Gardasil[2] -- protect against cervical cancer; Gardasil also protects against genital warts and anal, vaginal and vulval cancers.


Right now, boys and girls ages 11 and 12[3] are recommended by the Centers for Disease Control and Prevention to receive the HPV vaccine, as well as young women up to age 26 and young men up to age 21 who did not receive the vaccine earlier in life. Girls can be vaccinated with either Cervarix or Gardasil, while boys can only be vaccinated with Gardasil.


For the new study, researchers analyzed data from 3,551 adults who were part of the Health Information National Trends Survey from 2012 to 2013; of all the people in the study, 1,417 were determined to be HPV vaccine-relevant. Just 33 percent of the teen girls have received all three doses of the vaccine, with black, Hispanic and low-income women being less likely than others to have received the vaccine.


Seventy percent of people in the study said they were unsure of how well the vaccine prevented cervical cancer, and just 25 percent said that they'd actually talked to a health care provider about the vaccine.



"Findings suggest HPV communication and messages need refinement to clearly highlight vaccine efficacy, and targeted strategies may be needed to reach non-Hispanic Blacks and individuals with lower levels of education," the study said.



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  • An Abnormal Pap Test Means You Have High-Risk HPV


    Pap tests are the commonly accepted screening to prevent cervical cancer. A doctor scrapes a cell culture from a woman's cervix and then examines the cells for signs of abnormality. But just because a few of those cells appear abnormal, requiring further screening, doesn't necessarily mean that you've got a cancer-causing strain of HPV -- that's only one potential cause. "The difference could be due to local irritation, a non-HPV infection, a low-risk HPV type, or even a mistake in the preparation of the cell sample," writes the American Sexual Health Association.




  • Condom Use Prevents HPV


    HPV is passed via skin contact, rather than bodily fluid. For that reason, condoms can <em>lower</em> the risk of the disease, but they are not a sufficiently preventive measure, as they are for viruses like HIV and bacteria like gonorrhea.




  • Oral Sex Is Safe From Cancer Risk


    While the HPV-cancer connection most often relates to cervical health, a 2011 <em>Journal of Clinical Oncology</em> study found what doctors have long observed: There has been a surge in HPV-associated oral cancers. In fact, between 1988 and 2004, <a href="http://nyp.org/enews/oral-sex-hpv.html">HPV-associated oropharyngeal cancers rose 225 percent</a>. Oral sex is the primary culprit, making cancer screening of the mouth and esophagus another important test while visiting the doctor.




  • HPV Vaccine Means I Don't Have To Worry About Cervical Cancer


    The HPV vaccine protects against four strains of the virus that are most often associated with cancer and genital warts, but that doesn't mean it prevents cancer entirely. One concern within the medical community is that the vaccination will <a href="http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3104818/">provide a false sense of security</a> and prevent innoculated men and women from receiving regular cancer screening. "Clearer information is needed concerning the incomplete protection offered by the vaccine, and that cervical screening will still be required," wrote a group of British public health researchers in the <em>Journal of Medical Screening</em>.




  • HPV Is A Serious, Life-Long Condition


    About 90 percent of HPV infections <a href="http://www.cdc.gov/vaccines/pubs/surv-manual/chpt05-hpv.pdf">are resolved by the body's immune system</a>.




  • Genital Warts Can Be Pre-Cancerous


    Some strains of HPV (<a href="http://www.ashastd.org/std-sti/hpv/myths-and-misconceptions.html">"low risk" types 6, 11, 42, 43 and 44</a>) cause benign growths known as genital warts and other strains (types 16, 18, 31 and 45) cause cancer of the cervix, vulva, vagina, penis, anus, or an area called the oropharynx, which includes the back of the throat, the base of the tongue and the tonsils. But that doesn't mean that one leads to the other -- genital warts, <a href="http://www.cdc.gov/std/hpv/stdfact-hpv.htm">which affect about one percent of the sexually active U.S. adult population</a> -- do not lead to cancer.




  • The HPV Vaccine Is For Girls


    The first HPV-preventive vaccine on the market, Gardasil, was approved by the FDA for use in girls in 2006 and <a href="http://www.fda.gov/newsevents/newsroom/pressannouncements/ucm187003.htm">in boys three years later</a>. What's more, there are <em>two</em> FDA-approved vaccines for girls and women: Gardasil and Cervarix; while only Gardasil is available to boys and men. Still, HPV vaccination is the responsibility of all. Both the Centers for Disease Control and Prevention and the American Academy of Pediatrics both recommend the vaccine for boys for two primary reasons. First, inoculated boys will not be vectors for the disease, which can contribute to herd immunity and prevent dangerous infection in women. But more, the incidence of HPV-associated cancers that affect men is also growing, including anal and penile cancer and cancers of the mouth and throat.




  • Girls Who Receive An HPV Vaccine Will Be More Sexually Active


    <a href="http://www.time.com/time/nation/article/0,8599,1206813,00.html">Despite initial hand-wringing</a> that the vaccine could lead to promiscuity, a study of adolescent girls -- both those who had been inoculated and those who hadn't -- found no evidence that those who received the vaccination engaged in riskier behavior: they were no more likely to contract an STI, become pregnant or even seek out contraception -- a measure of intended sexual activity. "HPV vaccination in the recommended ages was not associated with increased sexual activity–related outcome rates," <a href="http://pediatrics.aappublications.org/content/early/2012/10/10/peds.2012-1516.abstract%7CSexual">the researchers wrote</a>.