To no one's surprise, a new clinical trial demonstrates that the human papilloma virus vaccine Gardasil is as good at protecting men as it is in protecting women, researchers reported Wednesday. A clinical trial in more than 4,000 boys and men demonstrated that the vaccine was more than 90% successful in preventing genital lesions caused by the four strains of HPV that the vaccine is active against, about the same level of protection demonstrated for women.
The vaccine is currently approved in the United States for both males and females over the age of 9, but current recommendations call for administration only to females. But the vaccine has been highly controversial, both because some view it as an implicit approval of sexual activity and because of its cost -- nearly $400 for a complete regimen of three doses. An estimated three-quarters of girls don't even start the regimen, and only about a third of those who do start it actually finish.
In the new trial, sponsored by the vaccine's manufacturer, Merck, Anna R. Giuliano of the H. Lee Moffitt Cancer Center and Research Institute in Tampa, Fla., and her colleagues enrolled 4,065 healthy boys and men, ages 16 to 26, from 18 countries who were HPV-free and who reported one to five sexual partners. Half received the vaccine and half a placebo.
The team reported in the New England Journal of Medicine that there were 36 genital lesions among those who received the vaccine, compared with 89 in the placebo group. But if the team considered only lesions caused by the four strains of virus covered by the vaccine, the efficacy was 90.4%. Average follow-up was nearly three years.
The results are "cause to celebrate the extraordinary potential" of HPV vaccination to improve public health, epidemiologist Jane Kim of the Harvard School of Public Health wrote in an editorial accompanying the report.
But the findings are likely to contribute to an already heated debate. By blocking penile and anal warts, the vaccine can reduce the incidence of the related cancers. But the incidence of both of those cancers is low, so critics of the vaccine argue that the public health benefits are not sufficient to justify the high cost of widespread vaccination for any male group other than, perhaps, homosexuals. Proponents, however, argue that women contract HPV from men and that vaccinating men bolsters herd immunity, thereby protecting women.
The argument is likely to continue for a long time.