“Vaccinate the boys, too: Preventing HPV in males would save lives — and money,” read the headline in an editorial last week in the National Post. The basis for the Post’s assurances that vaccinating boys would save the Canadian health system money? A study published this month in the journal Cancer that itself offers no such assurances.
The study, co-authored by Dr. Lillian Siu, a senior medical oncologist at the Princess Margaret Cancer Centre in Toronto, concluded that the $450-$500 HPV vaccines “may potentially save between $8 and $28 million [in Canadian dollars] for the theoretical cohort of 192,940 over its lifetime.”
The Post’s editorial writer then portrayed this iffiest of conclusions, over economic savings as small as $8 million over the lifetime of almost 200,000 people, into something Canadians could take to the bank. Those very iffy conclusions become iffier still upon examining the Cancer report, which rests on very iffy assumptions. To save the higher figure — $28 million — assumes that 70% of males take the vaccine and that it works 99% of the time. To save the lower figure of $8 million assumes a 50% uptake and a 50% effectiveness.
Yet there’s no reason to believe assurances that either of those effectiveness levels can be realized — the vaccine’s effectiveness rapidly wanes in boys, even faster than it wanes in girls. In just two years, for example, 38% lose all protection for HPV-18, one of the two cancer-causing types in the vaccine.
“We don’t know enough about what happens with the vaccine” to be confident of its efficacy or safety, warns Dr. Diane Harper, who was the principal investigator both for Merck, the pharmaceutical company that developed the Gardasil HPV vaccine, and for GlaxoSmithKline, which developed the competing HPV vaccine, Cervarix. Because the vaccine wanes in effectiveness so rapidly, booster shots are now being considered. But while boosters might extend the protection, they would blow a hole through the cost calculations — boosters, like the HPV vaccine itself, are expensive.
Ironically, the complexity of the economics was well illustrated in an article by Helen Branswell, medical reporter for the Canadian Press that appeared earlier this month in the same National Post. Branswell sought a second opinion in order to write a balanced article and found it in Dr. Natasha Crowcroft, chief of applied immunization research at Public Health Ontario, who stated that the cost-effectiveness of vaccinating boys can’t be accurately assessed without factoring in the impact of the program for girls.
“When you’ve got 50% uptake (in girls), it makes more sense to immunize the boys because then you increase your chances of getting herd immunity. Now we’re getting 80% per cent uptake in girls. It makes less sense to add the boys in.”
Another lesson from Branswell’s article is that “costs and benefits need to be weighed. ‘If we’re using public funds, then we have to make careful choices. Because … we’re always taking money away from something else we could be doing.’”
For failing to properly read the Cancer article, and also to survey the literature, which makes it abundantly clear that the economics of the HPV vaccine is highly dubious for boys, the National Post’s editorial writer gets two Band-Aids.