Kate Coens of Illinois had seen the commercials for the HPV vaccine and knew it protected against most cervical cancers. So when her doctor suggested she get it, she agreed. But, as she tells Shots, she never got the subsequent two shots she needed to get the full immunity.
"I got busy with other things," says Coens, who was a graduate student at the time. She didn't have a follow-up appointment, so she simply never went back.
Coens is hardly alone. Research presented at the Ninth Annual AACR Frontiers in Cancer Prevention Research Conference this week found that most people who start the HPV vaccine -- which, in addition to protecting against some cancers, can prevent genital warts -- don't finish the regimen.
The study looked at clinical data of almost 10,000 eligible women and girls ages 9 to 26 from the University of Maryland Medical Center's outpatient gynecology clinics. Just over a quarter of them started the HPV vaccine series. And of those, about 30 percent received all three shots.
The CDC recommends the vaccine for 11- and 12-year-old girls, as well as girls and women 13 to 26 years old who haven't gotten the vaccine. But both Cervarix and Gardasil can be given to girls as young as 9.
Age played a role. Women younger than 18 were more likely to get more than one dose of the vaccine. Women in early adulthood might face complicating factors -- like going to college or transitioning back home -- that make it difficult to get all of their shots, says the study's lead author J. Kathleen Tracy, a health psychologist at the University of Maryland School of Medicine in Baltimore.
"Anytime you have a regimen that requires multiple visits, it makes it more challenging to adhere to," she says.
This research isn't the first to track HPV vaccinations rates among young women. Over the summer, the Centers for Disease Control and Prevention released a report finding that 44 percent of teen girls got the first HPV shot, and 27 percent got all three shots. A study earlier this year in the American Journal of Preventive Medicine found that 34 percent of teen girls in six states researchers surveyed had received at least one vaccine shot.
What sets her study apart, Tracy says, is her target population. "We're focused on an urban metropolitan setting, which has a much larger minority population," she says. Two-thirds of those who received the first shot of the vaccine were African American; however, African Americans weren't as likely to complete the dosage as their Caucasian counterparts.
To get more girls to come back for shots two and three, Tracy plans to study whether text message reminders make an impact.
That won't help Coens, who is now 27 and past the recommended age range. But is Coens concerned that she didn't follow through? "Maybe a little disappointed, but in the grand scheme of things it wasn't that important" to her, she says. Even so, Coens says that if she had gotten a reminder to come in, it might have helped get her back to the doctor's waiting room.