The vaccine was developed to prevent cancer caused by the human papillomavirus, which is typically transmitted through oral, anal or vaginal sex. The vaccine is recommended for preteen girls and boys to protect them before exposure to the virus, with catch-up vaccinations through age 26. But in a 10-to-4 vote, the advisory committee agreed to recommend HPV vaccination for women and men ages 27 to 45 who are not adequately vaccinated, through “shared clinical decision-making.”
One committee member said although most people in that age group do not need the vaccine, it may be beneficial for a small number.
Those who voted against the change cited concerns about potential disparities in access to the vaccine and the global vaccine supply. Some committee members said they did not want to send a misleading message that vaccination at a younger age is not important.
According to the CDC, most sexually active people will contract HPV at some point. Some people may never know they have it, and the active infection may be short-lived because, in most cases, the body’s immune system suppresses the virus. Still, the virus can lead to many types of cancer, including cervical, anal, vaginal and penile as well as cancer of the throat.
Each year in the United States, about 17,500 women and 9,300 men get HPV-related cancer that in many instances could be prevented by vaccination, according to the CDC.
A commonly used vaccine, Gardasil 9, is designed to protect against nine HPV strains, seven of which are responsible for 90 percent of HPV-related cancers. Since its approval by the FDA in 2006, studies show that the vaccine has been effective in reducing the number of HPV infections that can lead to cancer.
In an analysis published Wednesday in the Lancet, researchers reviewed 65 studies in 14 high-income countries and found that more than a decade after introduction of the HPV vaccine, there has been a “substantial” decrease in HPV infections, precancerous cervical lesions and anogenital warts.
The researchers said that cases of HPV types 16 and 18 — which the CDC says cause 70 percent of cervical cancer — decreased by 83 percent among girls ages 13 to 19 and by 66 percent among women 20 to 24.
The study also noted a dramatic decrease in cases of precancerous cervical lesions among screened teenage girls and young women, and anogenital warts across all age groups of women and men.
Christopher Zahn, vice president for practice activities at the American College of Obstetricians and Gynecologists, said the study presents further evidence that “confirms the efficacy of HPV vaccinations.”
Zahn said he found it interesting that the study also discusses the benefits of “herd immunity.”
“In theory, as you vaccinate more and more people, the ability to spread disease also decreases,” he said.
On Wednesday, the CDC’s advisory panel voted to “harmonize” the age range for catch-up vaccinations among young women and young men, setting the age at 26. (Previously, catch-up vaccinations had been recommended for girls and women ages 13 through 26, but for boys and men ages 13 through 21.)
In a separate measure, the advisory committee voted to recommend catch-up vaccinations for older adults ages 27 though 45.
Last year, the U.S. Food and Drug Administration expanded its approval for the vaccine to include people in the older age group.
Public health experts agree that for adults up to age 45, the decision to get the vaccine should be based on each person’s sexual experiences and expectations and should be discussed with the person’s doctor. For example, a middle-aged person reentering the dating scene who had few previous sexual partners could become exposed to the virus for the first time and therefore might benefit from the vaccine.
The CDC recommends that children receive the first dose of the HPV vaccine between 11 and 12 years of age, then the second dose six months to a year later. However, the vaccine series can be started as young as 9 or after the target age, but those who receive it after age 15 may require three doses instead of two, the agency says.
Kathleen Schmeler, a gynecological oncologist at MD Anderson Cancer Center, noted that the vaccine may protect older adults from HPV strains to which they have not yet been exposed, but it will not protect them from previously acquired infections.
Schmeler said one concern she has is that many in the public might think, “’Oh, well, people can get it up to age 45 so we don’t need to give it to our kids now.’”
“I just think it’s really important to educate the public that it’s most effective [for children] both because of the kids’ immune response but also because they haven’t been exposed yet,” she said. Schmeler said there are also concerns about cost and global vaccine shortages.
Researchers say Australia, Rwanda and some European countries have been leading the charge with national vaccination programs that provide the shots to schoolchildren at no cost, and these countries may become the first in the world to eliminate HPV and, thus, HPV-related cancers.
Since 2007, when Australia implemented its National HPV Vaccination Program, more than 9 million vaccinations have been given to girls and young women, and there has been a 77 percent reduction in HPV strains that cause most cervical cancer, according to Cancer Council Australia. In 2013, the program was expanded to include boys.
In the United States, HPV vaccination rates have been rising, too, but at a much slower pace — and not fast enough to curb the rising rates of HPV-related cancers.
Public health experts blame inadequate access and education, as well as health-care providers who have shown reluctance in recommending the vaccine as strongly as required vaccinations.
Deanna Kepka, an assistant professor in the College of Nursing at the University of Utah and an investigator at Huntsman Cancer Institute, said one impediment to broad acceptance of the vaccine is the way it was introduced — as a vaccine to protect girls against sexually transmitted disease, rather than one to protect everyone against cancer. She noted oropharyngeal cancers, some of which can be caused by HPV, affect more men each year in the United States than cervical cancer affects women.
Schmeler, the gynecological oncologist, encouraged parents to have their children vaccinated, adding, “I spend my days taking care of women with cancer, many of whom die of the disease."