Male HPV Vaccine
In men and boys, the vaccine is expected to prevent common genital/penile warts and about half of penile cancers, a rare disease. In addition, the vaccine is expected to prevent oral, head and neck cancers due to HPV infection, the incidence of which is increasing, especially among men. HPV infection also is the primary cause of anal cancer. In the United States, anal cancer incidence is increasing among both women and men. HPV infection rates are especially high among HIV-positive men and women, health care providers note, and the highest rates of HPV-associated cancers occur among men who have sex with men.
The delay in studying the vaccine in men has puzzled many. Men are, after all, carriers of this virus known to infect the female cervix, leading to a virtual epidemic of abnormal Pap smears in sexually active young women. Although in most women the virus is cleared by their immune system, when it’s not it continues to percolate for years and each year accounts for the almost 11,000 cancers of the cervix-a cancer that robs women of their fertility if not their life. Ignoring the role of men in promulgating this illness is at odds with how we approach most other forms of STDs, where doctors treat both partners. Leaving men out also context of vaccinations creates a void in immunity. There is a growing concern, though little voiced, that boys should be included in the vaccination trials.
Earlier studies showed that boys and girls mount similar immune responses to Gardasil. But the new phase III clinical trial is the true test of whether the vaccine prevents HPV infection in males. Even so, male vaccination already is approved in some other countries. If the vaccine is effective in males, then for men who have sex with men, it will be beneficial, health care providers say.
In 2006, the U.S. government licensed the vaccine for use in girls and women ages 9 to 26. Males can spread the virus, but the vaccine was not licensed for them because there was no evidence it prevented disease in men. Though about 40 other countries have approved the vaccine for males, there still is little medical proof Gardasil prevents penile cancer or other HPV-associated cancers in men. There also is no evidence it prevents men from spreading HPV to women. Current studies are being developed to track HPV and cancer in men.
One new study involved about 4,000 males ages 16 to 26 in nearly 20 countries. Results showed the vaccine was 90 percent effective in preventing genital warts, with only 15 cases of persistent infection in the vaccinated group, compared to 101 cases in a group that was given a fake vaccine. Still, the results are expected to bolster a likely bid by the vaccine’s manufacturer, Merck & Co. Inc., to begin marketing the vaccine to boys, experts said. Merck plans to ask the government for that approval later this year. Another consideration is that if not all girls get the three recommended doses, then vaccination of boys could help increase collective "herd immunity," further lowering HPV transmission and, ultimately, cervical cancer incidence.
The results are "very exciting," but it’s not clear they will be enough to persuade many American families to get their teenage boys vaccinated, said Dr. Maura Gillison, an HPV researcher at Johns Hopkins University who was not involved in the Merck study. She noted that only 1 in 4 girls have gotten the vaccine so far, despite compelling medical studies that indicate the shots prevent female cancers.
Krishnan, Shoba; The HPV Vaccine Controversy: Sex, Cancer, God, and Politics: A Guide for Parents, Women, Men, and Teenagers