MONDAY, Nov. 14, 2011 (HealthDay News) -- Although the number of teens getting three new recommended vaccines is growing, there's still room for improvement, government researchers report.
The three vaccines were added to the recommended list of vaccines in 2005 through 2007. They include the TdaP vaccine, which shields against tetanus, diptheria and whooping cough (pertussis); the meningitis vaccine (MenACWY) and the human papillomavirus (HPV) shot for girls, which prevents about 70 percent of cervical cancers and vaginal warts.
Overall, the proportion of 13- to 17-year-olds who were up-to-date on these three shots rose from 10 percent in 2006 to almost 42 percent by 2009, the team from the U.S. Centers for Disease Control and Prevention found.
"On the good side, vaccination coverage is increasing," said lead researcher Shannon Stokley, from the CDC's National Center for Immunization and Respiratory Diseases.
"But, unfortunately coverage for HPV is starting to level off," she said. "We are not seeing as big an increase in coverage as we see with the other vaccines."
Stokley said one reason HPV vaccine is lagging is that many doctors don't strongly recommend the HPV vaccine for girls aged 11 and 12, and they often tell parents that it's OK to wait, she said.
However, HPV is transmitted via sexual contact and, "we feel it's really important to get the vaccine as early as you can, to make sure girls are protected at the time they may become sexually active," Stokley said. "The point of vaccination is to protect yourself before you are at risk."
Recently, a CDC panel recommended the HPV vaccine for boys. "We are hoping there will be strong uptake for boys," she said. Vaccinating boys helps stop the virus from spreading to girls and also shields boys from throat and anal malignancies.
Often parents aren't aware that teens need vaccines, Stokley noted. "You forget that there are vaccines recommended for adolescents and even for adults," she said. "Vaccines are recommended throughout life -- it doesn't end at kindergarten."
The report is published in the December issue of Pediatrics.
For the study, Stokley's team used data from the 2006-2009 National Immunization Survey -- Teen, which assesses vaccination coverage in U.S. children aged 13 to 17.
The researchers found that over the period, the number of teens getting the TdaP shot rose from 11 percent to 56 percent. For the meningitis vaccine, the rate went from 12 percent to 54 percent.
The HPV vaccine regimen is given in three separate shots. The number of girls who got at least one dose of the HPV vaccine climbed from 25 percent in 2006 to 44 percent in 2009, while the number of girls who got all three required doses went from 18 percent to 27 percent, the researchers said.
If doctors had given all the needed vaccines to their teenaged patients in 2009, TdaP and meningitis vaccine coverage could have been as high as 80 percent and coverage for the first shots for HPV could have reached 74 percent, the researchers noted.
According to the report, the main reasons for parents not getting these vaccines for their teens were: not knowing about the vaccine, not having the vaccine recommended by a doctor and (for TdaP and meningitis) believing that the vaccine was not necessary.
For the HPV vaccine, some parents said they didn't know about the vaccine, they believed it wasn't needed because their child was not yet sexually active or they didn't think the vaccine was necessary to prevent HPV.
And coverage rates for the three new vaccines varied widely by state: from a low of about 15 percent in Mississippi to a high of more than 63 percent in Rhode Island.
Infectious disease expert Dr. Marc Siegel, an associate professor of medicine at New York University in New York City, believes that "the low level of HPV vaccination is because parents can't conceptualize protecting someone against a sexually transmitted disease when their kids aren't having sex."
Parents also underestimate the extent of the HPV epidemic, Siegel said.
"There are 6 million new cases [of infection] a year -- 80 percent of the population turns HPV positive in their lifetime -- it's not a debatable thing," he said.
The goal of vaccination is to decrease the amount of circulating virus, creating what's called 'herd immunity,'" Siegel said. "To do this, you've got to vaccinate a lot more than we are seeing here."
"The purpose of vaccines is to protect society," Siegel said. "These diseases are emerging and -- in the case of HPV -- epidemic. The only way to control it is with vaccine. The risk of the vaccine is outweighed by the risk of the disease."
For more information on vaccinations for teens, visit the U.S. Centers for Disease Control and Prevention.