About 53 percent of Utah girls between ages 13 and 17 received at least one dose of the three-dose vaccine in 2011, according to the Centers for Disease Control and Prevention's National Immunization Survey.
But Utah ranks lowest in the nation for completion of the three-injection series among those who start it: 42 percent, compared with the national rate of 71 percent.
Utah's track record with boys is even worse.
"We don't even have enough males doing the vaccine to get national stats on it," said Deanna Kepka, an assistant nursing professor at the University of Utah and a researcher at Huntsman Cancer Institute.
The CDC has recommended the vaccine for preteen boys since 2011.
The vaccine offers the best protection to girls and boys who receive all three doses by age 11 or 12, in time to develop immunity before they become sexually active, the CDC says.
There are myriad reasons for its unpopularity, said Kepka, who has been researching the attitudes of Utah parents.
Roughly 83 percent have heard of HPV and 81 percent have heard of the vaccine, preliminary findings show. But only 25 percent of parents with age-eligible girls say they are likely to vaccinate their child.
The shots aren't perceived to be necessary, partly because parents say doctors aren't recommending it, said Kepka. That could be because teens don't routinely visit a doctor like they often do when they are younger, she said.
Persuading teens to return for multiple shots can also be a hard sale.
"We just don't know a lot," said Kepka, who hopes to poll physicians directly. "As far as I know, I'm the only faculty-level researcher [in Utah] looking at it."
Another barrier is that some parents don't believe their child will be sexually active soon, Kepka said.
HPV is the most common sexually transmitted infection. Most types infect the genital areas, but some infect the throat and mouth, according the CDC.
The vaccine has been shown to protect against the types of HPV that cause cervical cancer, most genital warts and anal, vaginal and vulvar cancers.
"There are no data on efficacy of the vaccine to prevent cancers of the penis, but most HPV-related cancers of the penis are caused by the HPV types prevented by the vaccines," says the CDC's website.
The HPV immunization is not among those required to attend public school in Utah. Mandates in other states haven't fared well.
Utah public health officials do promote it. "It's on our list of routine vaccinations," said Becky Ward, a health educator with the state Department of Health. "And we've made some gains."
In 2012, the number of teen girls who completed the series rose to 55 percent. But the rate of girls starting the series dropped to 44 percent, the health department reports.