HPV vaccine: Why boys are less likely to get it

A Conservative MP'stongue and throat cancer scare is reigniting the debate over whether young boys should receive theHPV vaccinefor free.

During his nine-month bout of cancer, Peter Kent says,doctors convinced him it's important to vaccinate boys against human papillomavirus.

• MP beats throat cancer, urges HPV vaccine for boys

Two types of HPVcause 70 per cent of cervical cancer in women, according to the Canadian Cancer Society. In men, the virus is responsible for a high percentage ofmouth, nose andthroat cancers, as well as some cancers of the penis and anus.

Girls between ages nineand 13 attending school anywhere in Canada can opt to receive a free HPV vaccination.

Our big concern is that it's out there and that people aren't taking advantage of it.-Dr. RobertNuttall, the Canadian Cancer Society's director of cancer control policy

Only two provinces, Alberta and Prince Edward Island, offer the same choice to young boys. Outside of those two provinces, boys can still be vaccinated, but onlyif their parent orguardianchooses to pay out-of-pocket.

"Our big concern is that it's out there and that people aren't taking advantage of it," Dr. Robert Nuttall, the Canadian Cancer Society's director of cancer control policy, told CBC News.

"Soanything that would make it easier or more accessible for boys would be a win."

The vaccinehasproven not only to protect women from certain types of cancer, but also men, Nuttall explained, with it preventing about 70 per cent of anal cancers.

The cancer society "strongly urges" governments and health authorities to work together and ensure boys and young men receive the vaccine, he said.

It's a call echoed by the Canadian Medical Association, which "strongly supports the call for public funding" for vaccinating both genders, CMApresident Dr. Chris Simpson wrote in a statement to CBC News.

'It's a question of cost'

Eduardo Franco, director ofMcGillUniversity's division of cancer epidemiology, has been studying HPV for the past three decades. Some 20 years ago, his research helped prove that HPV can cause cervical cancer.

He's now conducting a long-term study of how vaccination prevents male-to-female viral transmission andvice-versa.

Franco said it's a given that both men and women should be vaccinated.

"It's a question of cost, of course," he explained.

One of the two vaccines approved in Canada, Gardasil, was once regarded as the costliest shot available in the world. It now costs about $100 per dose for HPV vaccination in Canada, Franco said. At three doses per person, that's roughly $300 a child.

It's only considered cost-effective to offer boys vaccinations if not enough girls are opting for the shots, Franco explained.

When less than half of girls choose to be immunized, it's cost-effective to start providing publicly funded shots for boys, according to a 2014 report by the Canadian Immunization Committee, outlining recommendations for the country's HPV immunization programs.

Only vaccinating girls banks on the effectiveness of a system called herd immunity. If enough of one segment of a population is protected, it can reduce the prevalence of the virus in the whole population.

Vulnerable population left exposed

But that system misses a key demographic.

"There's always a segment of the population men who have sex with men that will not be protected," Franco said.

When Canada's National Advisory Committee on Immunization released its 2012 recommendations for who should obtain an HPV vaccination, the list included not onlyall men between nine and 26 years old, but also men older than 26 who engage or have engaged in same-sex sexual activity.

"Compared to the general population, [these men] have disproportionately high burden of HPV infection, especially vaccine-preventable high-risk types," read the report.

Franco calledthat "one good reason" to overrule the cost-effectiveness argument and start publicly funding vaccinations for boys as well as girls.

Another good reason can be future costs.

In 2013, when Alberta became the second province to offer HPV vaccinations to boys, itactually cited cost-effectiveness as a reason for the decision.

"Our investments today will reduce health care costs tomorrow and most importantly, prevent future cases of cancer in Alberta," Fred Horne, the province's health minister, wrote in a statement at the time.

Experts understandthat each province and territory has to weigh its financial priorities when making this decision. After all, funding the vaccine for boys may mean other pertinent health initiatives go without.

Ontario is currently re-assessing its position, said David Jensen, a spokesman for the provincial Health Ministry.Among other things, the ministry is assessing economic factors and "cost-effectiveness and impact on the health system."

However, cost may not be an issue for much longer.

"A day will come in which all of these questions will be a moot point," said Franco, explaining that the cost of vaccinations is likely to drop as manufacturers develop new vaccines and old patents expire.

"Eventually, we'll no longer be discussing along the lines of cost effectiveness and we'll just adopt it."