— If you thought the controversy over giving the HPV vaccine to girls was heated, just wait for the fight about the boys.
A government health panel is expected to vote soon on whether to recommend vaccinating boys and young men against the human papillomavirus. Since 2006, the vaccine has been advised in girls and young women ages 9 to 26 to prevent cervical cancer and genital warts — though only about a third of those eligible actually have received it.
From the start, arguments about whether to inoculate males against HPV have centered mainly on the benefits for women — and the desire to stop men from transmitting the most common sexually spread infection. The vaccine is approved, but not recommended, to prevent genital warts in males.
But now, growing evidence shows that the vaccine also may prevent anal cancer, particularly in the high-risk groups of homosexual and bisexual men, who are about 20 times more likely than heterosexuals to develop the disease.
Next week, an advisory panel to the federal Food and Drug Administration will consider whether to recommend expanding use of the vaccine based on clinical data that show it could be up to 78 percent effective in preventing anal lesions and anal cancer in men who have sex with men.
Dilemma: targeted vs. universal vaccine?
If it's approved, it creates a dilemma, say panelists charged with the new decision. Do they opt for a targeted vaccine aimed only at gay and bisexual males? Do they support a universal vaccine for men and boys, perhaps as young as age 9? Or do they continue to exempt males from vaccination altogether?
“It’s a conundrum,” said Dr. James Turner, immediate past president of the American College Health Association and a liaison to the Advisory Committee on Immunization Practices (ACIP). “The conundrum is many times boys or teenagers don’t really fully understand or clarify their sexual orientation for years.”
That means a vaccine targeted to young men who know they’re gay or bisexual likely wouldn’t reach many of the males who may need it, or reach them early enough. With boys, as with girls, the HPV vaccine is most effective when it’s given before sexual activity exposes people to the virus, health experts say.
“In general, targeted vaccine programs based on risk factors tend not to be nearly as effective at reaching that population as universal vaccination in that group,” said Turner.
In addition, there’s the danger that the stigma of a vaccine aimed only at young gay and bisexual boys and men would hinder use.
“I’m advocating it for all boys,” said Turner.
But HPV vaccine critics contend that it’s overkill to recommend vaccinating all boys and men in order to protect a small group from what’s estimated at about 5,000 cases of HPV-related invasive cancers each year.
“It’s hard to imagine why they want to vaccinate all these boys,” said Sheila Rothman, a professor of public health at Columbia University who was an early critic of drugmakers’ eagerness to vaccinate girls against HPV.
“There’s this whole question of vaccinating a whole population with a small risk."
Overall, about 5,260 new cases of anal cancer are diagnosed each year, with about 720 deaths reported, according to the National Cancer Institute. In the general population, about 1.6 people per 100,000 develop anal cancer, with a slightly higher proportion of women to men.
Far higher rates of anal cancer in gay, bisexual males
Among men who have sex with men, however, the rate jumps to about 40 cases per 100,000 men. If those men have HIV, the rate spikes to 80 cases per 100,000 men, research shows.
There are more than 100 strains of HPV, but only a few strains are known to cause most cervical and anal cancers, some head and throat cancers and genital warts. The virus is spread by sexual contact, including intercourse and oral sex, but can also be spread by mere skin-to-skin contact.
About 6 million new HPV infections occur in the United States each year, according to the National Cancer Institute. Most are cleared by the body naturally within a few years, although the most dangerous types persist.
Two vaccines are approved to prevent HPV infection. Merck’s Gardasil, which targets four strains of HPV responsible for most cervical cancer and genital warts, was approved in 2006 for use in girls and women. Last year, the FDA expanded approval of the vaccine to prevent genital warts in boys and men. On Nov. 17, an FDA advisory panel is set to consider expanding the use again to protect against anal lesions and anal cancer in both sexes.
GlaxoSmithKline's Cervarix, which targets two strains of HPV responsible for 70 percent of cervical cancer cases, was approved last year to prevent disease in girls and women.
New data from a Merck clinical trial of 602 men who have sex with men showed that the vaccine was 78 percent effective in preventing certain anal lesions and cancers in the high-risk group.
Merck scientists are urging the FDA to extrapolate efficacy in gay and bisexual men to the larger population of all men — and women.
"The key concept is that the disease is same in everybody," explained Dr. Elizabeth Garner, director of clinical research for Merck Research Labs. "They happen to be men who have sex with men, but the disease is the same in everybody and it should work in the same way."
But critics like Columbia's Rothman argue that while vaccine use in gay and bisexual men may be important, that doesn't argue in favor of wider vaccination.
The three-dose series of the vaccine is expensive, about $100 for each shot, and, despite government analyses and assurances of safety, Rothman and others are concerned that the vaccine hasn’t been used long enough to be certain.
“I can imagine an educational campaign targeted at a small group,” Rothman said. “Of course, that would mean Merck and GlaxoSmithKline would get less sales.”
Together, the HPV vaccine makers posted sales of nearly $111 million last year, based on wholesale acquisition costs. So far this year, sales have totaled nearly $74 million, according to data from research firm Wolters Kluwer Pharma Solutions.
Is benefit worth the cost?
The main arguments against vaccinating boys have been that the vaccine is expensive, and that it’s not cost-effective to do so, said Dr. Lauri Markowitz, a expert in sexually transmitted diseases with the Centers for Disease Control and Prevention who is heading the ACIP HPV workgroup. She said panel members who support recommending the vaccine for males won't be swayed solely by the benefit to gay and bisexual men.
But that argument may be tempered by a new study by a Harvard University researcher that showed a targeted HPV vaccination of men who have sex with men is likely to be a cost-effective way to prevent deadly disease specifically in that population.
So far, use of the HPV vaccine in girls has been limited. About 44 percent of eligible girls get the first dose of the vaccine, but only about 27 percent get all three doses, according to latest data from the CDC.
That’s mostly spurred by parents’ worries over potential safety risks — and by their reluctance to immunize their young daughters against sexually transmitted disease, said Shannon Stokley, a researcher from the CDC's National Center for Immunization and Respiratory Diseases.
More than half of parents in a recent survey said they were not likely to vaccinate their daughters against HPV, and the top reason was that the girls were not yet sexually active, Stokley told the ACIP panel.
For comparison, less than 1 percent of boys have been vaccinated at HPV so far, ACIP presenters said.
Vaccine for boys ‘a tough sell’
If parents feel so strongly about not vaccinating girls, they’ll likely feel the same about their boys, said Amie Newman, the mother of an 11-year-old son and managing editor for the reproductive health blog RH Reality Check.
“I think it’s going to be a tough sell, personally, to get parents to vaccinate their male pre-teens before they’re sexually active,” said Newman, 41, who lives in Seattle.
Throw in the issue of homosexuality or bisexuality and receptiveness will decline even further, predicts Rothman, the Columbia University expert.
“I think parents are just going to shun it for boys,” she said.
But those parents might be doing their sons — and daughters — a disservice, said Liz Margolies, executive director of the National LGBT Cancer Network, an advocacy group. Sexuality is fluid and even people who don't expect to be exposed to HPV — such as those in a long-term relationships — might be, she noted.
"I believe all males, and all females, ought to be vaccinated without question," she said.
Discussion about whether to recommend vaccination of boys is intense and ongoing, said the CDC's Markowitz, who expects a vote early next year.
“There’s no consensus on that yet,” she said. “I don’t know myself.”