THURSDAY, Aug. 23, 2018 (HealthDay News) -- HPV vaccination rates continue to climb in the United States, jumping a full 5 percentage points between 2016 and 2017, a new government report shows.
Nearly 66 percent of boys and girls aged 13 to 17 received the first dose in the vaccine series in 2017, according to the U.S. Centers for Disease Control and Prevention researchers. Further, nearly 49 percent of adolescents received all the recommended doses to complete the series.
The human papillomavirus (HPV) causes most cases of cervical cancer.
"Vaccination is the key to cervical cancer elimination," CDC Director Dr. Robert Redfield said in a statement Thursday. "I'm pleased to see parents are taking advantage of this crucial public health tool and thank the clinicians who are working to ensure all children are protected from these cancers in the future."
But a second report released by the CDC shows there will be some lag time before the vaccine triggers a decrease in cancer rates.
The number of HPV-associated cancers increased from 30,000 to more than 43,000 annually between 1999 and 2015, mainly due to a rise oral and anal cancer among men and women, the second study found.
"We will not see the effect of the HPV vaccine regarding cancer for some time," said Dr. Stephanie Blank, director of gynecologic oncology for Mount Sinai Health System in New York City. "The vaccine is given before age 27, and cancers occur significantly later."
Human papillomavirus (HPV) causes nearly all cases of cervical cancer, and also is a leading cause of anal, oral, vaginal and penile cancers, the U.S. National Cancer Institute says. It is transmitted primarily through sexual contact.
Although doctors are encouraged by the increase in HPV vaccination rates, it's still not widespread enough to eliminate the virus as a cause of cancer.
"To really make the potential of cancers caused by HPV go away almost completely, we really want to get the coverage to 80 percent or more of boys and girls," said Dr. Howard Bailey, director of the University of Wisconsin Carbone Cancer Center.
Still, more awareness and better education regarding the vaccine has contributed to the increase in vaccination rates, Bailey said.
But vaccination rates are not even across the country. Fewer teenagers in rural areas, compared with youth in urban areas, are getting the HPV vaccine, the CDC said.
The number of adolescents who received the first dose of the HPV vaccine was 11 percentage points lower in rural areas compared to urban areas, the researchers found.
The vaccine has been available now since 2006. "That's 12 years, and we're still struggling. People don't think they're going to get cancer. That's the problem," said Dr. Larry Copeland, a gynecologic oncologist with the Ohio State University Comprehensive Cancer Center.
To get vaccination rates higher, doctors will need to come up with ways to counter parents' concerns, said Dr. Len Horovitz, an internist with Lenox Hill Hospital in New York City.
"Many people have a very warped idea of vaccines in general," Horovitz said. "This one, especially, because it's tied in their minds perhaps to permission to engage in sexual activity, is all the more vexing."
Copeland said he frequently asks younger cervical cancer patients why they didn't get the vaccine.
"I get a variety of answers. The most common probably is, well, Doctor, it wasn't recommended to me. I wasn't told to get it," Copeland said. "Clinicians are dropping the ball."
The second report also found that oropharyngeal cancer -- cancer of the back of the throat -- is the most common HPV-associated cancer in the United States.
Between 1999 and 2015, rates of oropharyngeal cancer increased in both men and women, about 2.7 percent per year in men and 0.8 percent per year in women.
The report also found that in 2015, roughly 43,000 men and women developed an HPV-associated cancer, or a cancer in the part of the body where HPV is often found. HPV causes 79 percent, or about 33,700 cases, of these cancers every year, the CDC says.
HPV vaccination could prevent 90 percent or 31,200 cases of cancers caused by HPV from developing in the United States each year, the CDC report concluded.
The two new studies appear in the Aug. 24 issue of the CDC publication Morbidity and Mortality Weekly Report.
The U.S. National Cancer Institute has more about HPV and cancer.