It is assumed in the developed world that it will be recommended that men be immunized, but it is not such a straight forward issue. There are several points. The first is that at the moment there is no evidence that immunizing men is beneficial. It might be useful to do studies that indeed show that the vaccine would have some protection -- not so much to protect men against HPV-16, but to have a rationale for immunizing men as a way to protect women.

The second issue is that the more protective the vaccine is for women, the better off you would be in immunizing all women, rather than immunizing two-thirds of men and two-thirds of women. You would get more protection if you immunize 100 percent of women, rather than immunizing two-thirds men or two-thirds women. To make the vaccine more relevant to men, Merck is incorporating HPV-6 and HPV-11, which are the main causes of genital warts, which are as big a problem for men as women. If there is a reduction in infection with those HPV types, then men would get a direct benefit.