Updated

Federal health officials urged doctors on Thursday to become more active in recommending the human papillomavirus (HPV) vaccine to parents of adolescents. The sexually transmitted disease is blamed for an estimated 26,200 new cases of cancer each year – 17,400 of which are women.

The announcement came as the Centers for Disease Control and Prevention (CDC) released results of a survey on HPV vaccine coverage among girls aged 13 through 17. The survey results, published in the CDC's Morbidity and Mortality Weekly Report (MMWR), showed that nearly 54 percent of girls in this age group have received at least one of the three recommended doses of HPV vaccine.

That figure marks a dramatic increase from the 25 percent coverage reported in 2007, the year after public health officials began recommending routine HPV vaccination for girls at the ages of 11 or 12.

However, the survey suggests the trend began to level off in 2011, when 53 percent of girls in this age group had received at least one dose of HPV vaccine. And the percentage of girls aged 13 through 17 who have received all three recommended doses (33 percent) actually declined slightly from 2011 to 2012.

"We assumed that one of the reasons we had such low rates was that adolescents don't see the doctor regularly, so it's hard to get a three dose series in," said CDC director Dr. Tom Frieden. "But actually… the data showed that if HPV vaccine were given every time a young person went to the doctor to get another vaccine, the completion of those series would be at 93 percent."

Public health officials have set a goal of boosting the percentage of adolescent girls receiving the full HPV vaccine series from the current 33 percent to 80 percent. The CDC estimates this could prevent some 4,400 new cases of cervical cancer each year.

Among the reasons parents gave in the survey for not vaccinating their daughters, 19 percent believed the vaccine was not needed, and 14 percent said no one recommended it to them. Just over 13 percent cited concerns over the safety of the vaccine, and nearly 13 percent said they were unaware of the vaccine or the disease. Around 10 percent said their daughters didn't need the vaccine, because they were not sexually active, according to the survey.

In safety monitoring studies, fewer than one in 2,600 patients who received the vaccine reported adverse symptoms, ranging from redness at the injection site to headaches and dizziness. More than 92 percent of those symptoms were classified as non-serious.

Because many of these symptoms can also occur in people who have not been vaccinated, researchers look for trends to determine possible links. CDC officials said extensive studies of the HPV vaccine identified no serious safety concerns.

According to public health officials, separate studies suggest girls who receive the HPV vaccine are no more likely to engage in sexual activity than unvaccinated girls.

"HPV vaccine does not open the door to sex. HPV vaccine closes the door to cancer," Frieden said.

As with vaccines for other illnesses, the goal is to vaccinate children long before exposure to a disease so they have time to build up immunity, according to Frieden. He argued that doctors need to take on a more active role in discussing HPV and the vaccine with parents.

"Research consistently shows that a provider's recommendation to vaccinate is the single most influential factor in determining whether a parent gets their kid vaccinated," Frieden said.

The CDC estimates that 79 million Americans are already infected with HPV, with 14 million new cases reported each year.

Of the 17,400 women diagnosed with HPV-related cancers each year, 10,300 are diagnosed with cervical cancer. Approximately 8,800 men are diagnosed with HPV-related cancer each year with mouth and throat cancers as the most common.

Public health officials began recommending routine HPV vaccination for boys at the ages of 11 and 12 in 2011. They also recommend the vaccine for older teens and young adults who have not previously received it (up to age 21 for males and 26 for females).