Elizabeth Weise, USA TODAY
A vaccine that protects women against cervical cancer has proven a tougher sell than health workers had hoped, with vaccination rates stalling from 2011 to 2012.
Since 2006 the Centers for Disease Control and Prevention (CDC) has recommended that all girls 11 and up get three doses of the human papillomavirus vaccine, which protects against 70% of cervical cancers that can appear 20 to 40 years later. The vaccine also protects against 90% of genital warts.
Vaccination rates increased substantially in the first five years the vaccine was available. By 2011, 53% of girls had gotten at least one dose of the HPV vaccine. However in 2012 the increase stopped, staying at just 53.8%, according to a paper in this week's edition of the Morbidity and Mortality Weekly Report published by the CDC in Atlanta.
"Progress increasing HPV vaccination has stalled, risking the health of the next generation," said CDC Director Tom Frieden.
The vaccine is highly effective. A study released in June found that the vaccine had decreased the incidence of the cancer-causing virus among teenage girls by 56%, despite being available only since 2006.
The HPV vaccine comes in a series of three shots over six months or longer. CDC recommends that both girls and boys receive all three doses before they become sexually active. Because the recommendation for boys was only added in 2011, data were only collected for girls.
The reasons behind the standstill are varied. A 2012 survey of families with teen girls who said they didn't plan on having their daughters vaccinated found that 19% said their daughter didn't need the vaccine, 14% hadn't had the vaccine recommended to them by their doctor, 13% had safety concerns about the vaccine, 12% didn't have knowledge of the vaccine or the disease and 10% said their daughter wasn't sexually active.
"Doctors need to step up their efforts by talking to parents about the importance of HPV vaccine just as they do other vaccines and ensure it's given at every opportunity," Frieden said.
"This vaccine is preventive," said Shannon Stokley, one of the paper's authors. She is with the National Center for Immunization and Respiratory Diseases. "If you do have an infection later in life, you can't get the vaccine to make it go away. We're so lucky that we have a vaccine to prevent these cancers - there aren't many diseases where we can do that."
If every girl 11 and up who saw a health care worker since 2007 had been encouraged to get the HPV vaccine, coverage could have reached 92%, the paper stated.
Some parents have balked at having their children and teens vaccinated for a sexually transmitted disease out of concern that it could encourage sexual activity. Two studies have shown that getting the HPV vaccine has no effect on sexual activity, Stokley said.
As for young women not being sexually active, Frieden said the vaccination is given to younger girls to protect them when they become adults, just as children are vaccinated for measles well before a child may get exposed.
Fears about the safety of the vaccine may have been stoked by anti-vaccination websites claiming that thousands of girls have had serious reactions to the HPV vaccine and more than 100 have died.
Those numbers do not appear to be based on actual data. In the United States, vaccine safety monitoring is conducted by federal agencies and vaccine manufacturers. Out of the more than 56 million doses of the HPV vaccine distributed sine 2006 there had been only 21,194 adverse events reported, mostly pain at the site of the shot, redness and swelling. Reports classified as "serious" adverse events included headache, nausea, fainting, dizziness, vomiting and generalized weakness. There were 1,674 reported instances of these. There have been no deaths linked to the vaccine, said Cindy Weinbaum, a medical epidemiologist with CDC's immunization safety office,
Certain diseases appear during adolescence, around the same time as the HPV and other vaccines are given. Some parents may worry that the two are linked. However, Weinbaum said they have been unable to find any links. "We've been doing a systematic review of medical records in managed care systems for any adverse events that occur after vaccination with the HPV vaccine and we haven't seen anything other than fainting."
But that's the case with all vaccines given to teens, said Weinbaum. "Adolescents receiving vaccines faint more than infants. That also happens with other vaccines given to teens, such as TDAP and the meningococcal vaccine," she said.
About 79 million Americans, most in their late teens and early 20s, are infected with the human papillomavirus. Each year, about 17,400 women in the United States get cancer caused by the virus, with cervical cancer being the most common type.
Men can also get cancer from the human papillomavirus. Each year about 8,800 men get these cancers, mostly in the throat. The CDC began recommending in 2011 that boys over 11 also get the vaccine.