The rate of HPV vaccination among teen boys in the United States surged in 2015, suggesting that more parents and physicians are embracing the message that it's as important for boys to be vaccinated against the human papillomavirus as it is for girls.
The Centers for Disease Control and Prevention reported Thursday that 49.8 percent of boys ages 13 to 17 had gotten at least one of the recommended three doses as of 2015, up 8 percentage points from 2014. The rate for teen girls rose more slowly: Almost 63 percent had gotten at least one dose, compared to 60 percent in 2014.
Vaccine proponents were cheered by the sharp rise in vaccinations among boys, who as adults could be at greater risk of certain cancers. "The rate is increasing faster for them than it ever has for girls," said Erich Sturgis, a head and neck cancer surgeon at MD Anderson Cancer Center in Houston.
Nancy Messonnier, director of CDC's National Center for Immunization and Respiratory Diseases, also said she was heartened by the latest numbers, which indicate that HPV vaccination is increasingly being viewed as routine. "Our message is getting through -- that the HPV vaccine is cancer prevention," she said.
The key to further improvement in vaccination rates, she said, is working with physicians to make sure they understand the importance of the vaccine and how to talk to parents about it.
Despite the positive change last year, the completion rate for all three doses continued to fall far short of the government's goal of 80 percent of adolescents. Just 42 percent of girls and 28.1 percent of boys had gotten all three doses. By contrast, 86.4 percent of adolescents had received the tetanus, diphtheria and pertussis vaccine, and more than 80 percent of had received meningitis vaccines.
Gardasil, the most widely used HPV vaccine, was approved by the Food and Drug Administration in 2006 for girls and in 2009 for boys. But for years, its use in males has lagged. Meanwhile, public health experts and physicians, including cancer doctors, are increasingly alarmed about an epidemic of HPV-related throat cancers with middle-aged and older men.
More than 9,100 HPV-related throat cancers, occurring in the tonsils and at the base of the tongue, are diagnosed in U.S. men every year. That compares to 10,000 cases of cervical cancers in women. The number of male throat cancers is expected to soon surpass cervical cancers, Sturgis said.
One problem, he noted, is that there's no way to screen for throat cancers -- with no equivalent of a pap smear for cervical cancer.
"With the cervix, doctors can see the surface and look for pre-cancerous cells and treat them," he said. But pre-cancerous growths or early throat cancer isn't visible.
The CDC report shows how much HPV vaccine coverage varies by state. Among boys, only about 35 percent had received at least one dose of the vaccine in Kentucky as of last year, compared to 80.6 percent in Rhode Island, which is one of a few states that requires the vaccine for school attendance. In girls, Wyoming had the lowest rate at 47.7 percent last year, while Rhode Island had the highest, almost 88 percent.
Currently, the vaccine's three doses are recommended for children ages 11 to 12, typically before sexual contact begins. The shots are given over a six-month period. The fact that HPV is transmitted by sexual contact has been the focus of the lingering controversy over the vaccine. Critics have questioned whether the vaccine makes teenagers promiscuous, though research has shown such concerns to be unfounded.
The nation’s leading cancer doctors have been pushing pediatricians and other providers to help increase the vaccine's use, which studies show could help avert tens of thousands of cancer cases over young Americans’ lifetimes. Merck, the maker of the vaccine, has been running television ads prodding parents to make sure their children are vaccinated.
Messonnier said about 30,000 men and women are diagnosed with HPV-related cancer in the United States every year. Besides cervical and throat cancer, some of the other common related cancers are of the anus, penis and vulva.
Correction: The interval for the vaccine's three doses was incorrect in an earlier version of this post.