Vaccinating boys against HPV could cut costs: study

TORONTO — A new study suggests giving boys the HPV vaccine could cut health-care costs over the long run.

The researchers used mathematical modelling to estimate the effect of giving the HPV vaccine to 12-year-old boys to prevent cancers of the mouth and throat.

The work suggests if all 12-year-old boys in Canada had been vaccinated in 2012, between $8 million and $28 million might have been saved because of oropharyngeal cancers averted.

The types of human papillomaviruses that cause cervical cancer are also responsible for some oropharyngeal cancers, which are rising.

Currently Prince Edward Island and Alberta offer HPV vaccine to boys as well as girls; on Friday, Nova Scotia announced it will follow suit in the fall.

“Gradually, bit by bit, perhaps, people are thinking that it is a good thing to do. Because there’s no reason why we shouldn’t protect the men also,” says Dr. Lillian Siu, a medical oncologist at Toronto’s Princess Margaret Cancer Centre. Siu is one of the senior authors of the study.

The authors admit the mathematical model they used did not take into account what’s known as herd immunity — the protective effect on the entire population of having a significant portion of people vaccinated against a given pathogen.

In this case that means the researchers did not factor into their calculations how vaccinating girls would affect the HPV risk faced by boys. Already research elsewhere has shown rates of genital warts and some HPV-related cancers in men are dropping in the wake of the introduction of public programs to vaccinate girls.

The belief is that as the number of girls and women who are protected against HPV rises, fewer of these viruses will circulate, so many males will get indirect protection. That group protection may not be as pronounced for males who have sex with other males.

It’s not possible to assess accurately the cost-effectiveness of vaccinating boys without factoring in the impact of the girls’ program, says Dr. Natasha Crowcroft, a vaccine expert at Public Health Ontario.

“The herd effect is so overwhelmingly important you can’t leave it out of any analysis,” Crowcroft says.

“Bit by bit, perhaps, people are thinking that it is a good thing to do.” Dr. L illian Siu, oncolo gist