In schools, clinics and doctors’ offices across Canada, girls are being vaccinated against the human papilloma virus, the leading cause of cervical cancer. Behind closed doors, a few boys are quietly being vaccinated, too. In Canada, the Gardasil shot is only approved for use in females aged nine to 26, but “many physicians have vaccinated their boys,” says Dr. Michel Fortier, president of the Society of Obstetricians and Gynaecologists of Canada, which doesn’t endorse the use of Gardasil in males. In a growing number of countries, males can get the vaccine. Do they know something we don’t?
Cervical cancer kills about 400 women in Canada each year, but it’s not the only HPV-related cancer. Beyond genital warts, the most common sexually transmitted infection, HPV has been linked to penile, head and neck, and anal cancers, to name a few. In fact, the virus causes about six per cent of all cancers around the world, says Dr. Nubia Muñoz, in Toronto this week to accept the Canada Gairdner Global Health Award for her research into the virus. If we’re serious about eliminating it in the “foreseeable future,” says Nobel laureate Dr. Harald zur Hausen, who discovered that HPV causes cervical cancer, “I would strongly advocate the vaccination of boys.”
Indeed, the U.S. recently licensed the use of Gardasil in males aged nine to 26, joining countries like Australia, New Zealand and 27 European Union nations where males can get the shot, too. Approval for use in males has lagged largely because early studies focused on women, says HPV researcher Dr. Daron Ferris at the Medical College of Georgia. (Health Canada wouldn’t comment on whether it’s considering extending the use of Gardasil, but said that Merck, its manufacturer, would have to submit data showing its safety and effectiveness in that group.)
Beyond offering protection to their female partners, Ferris thinks men could see a “tremendous benefit” from the vaccine, and a growing body of research suggests he’s right. One Merck-funded study followed 4,065 young men (in Canada and elsewhere) who got three shots of the vaccine or a placebo. After 30 months, three who got Gardasil had genital warts; among those who got the placebo, 28 did. “I’m a firm advocate of everybody getting the vaccine,” Ferris says, “because I see what happens to people who don’t.”
But some experts argue that if we vaccinate enough females, men will be protected, too. In Australia, which provided free Gardasil to women aged 26 and under for the last two years, 70 per cent have now been vaccinated. Cases of genital warts dropped sharply as a result: before the vaccine was rolled out, 15 per cent of young women who visited the Melbourne Sexual Health Centre had genital warts, says Dr. Christopher Fairley, its director. Now, it’s down to six per cent. Australian males, who have a much lower vaccination rate (unlike women, Fairley says, they weren’t offered the shot for free), have benefited indirectly. “We’ve seen a 20 per cent reduction in genital warts in heterosexual men,” he notes.
If that’s the case, some argue that vaccinating males doesn’t make economic sense. A study from the Harvard School of Public Health found that, if enough young girls get the shot, including boys might be an unnecessary cost. (With a cost of over $130 per dose, and three doses required, Gardasil isn’t cheap.) But zur Hausen, a past Gairdner winner who’s in Toronto for the awards this week, points out that vaccinating just females might take too long: “We’d reach our goal much faster if we also vaccinate boys,” he says.
Beyond that, there’s one group that won’t be protected no matter how many females get the shot: homosexual men, who are 17 times more likely to get anal cancer. In an article published in Xtra in 2008, Sky Gilbert argued that Gardasil may benefit gay men: “If even one death from anal cancer can be prevented, aren’t we obligated as a society to do so? What about us?” (The Harvard team didn’t look specifically at homosexual men.) Of course, the HPV shot works best when it’s administered before first sexual contact. If gay men are to receive the HPV vaccine, making it available to all boys or young men would be the only way.
Until the cost of the vaccine drops, zur Hausen notes, widespread male vaccination isn’t likely. (In the U.S., medical experts did not push for the routine use of Gardasil in boys, as they have in girls.) But there are promising signs: the U.S. just approved Cervarix, another vaccine already licensed in 100 countries around the world for use in girls. Having another vaccine to choose from could create competition, observers hope, and lower prices. (Health Canada is evaluating the safety and effectiveness of Cervarix before approving its use, officials say.)
Ferris, for one, believes that male vaccination will be an important step in eradicating a dangerous virus. “This is a historic moment: we have a cancer prevention vaccine,” he says. Now if only everybody could get it.