By Edward Pullen, MD. Check out drpullen.com, a medical blog for the informed patient.
HPV vaccine for boys age 11-12 is now recommended by the Advisory Committee on Immunization Practices, according to a Morbidity and Mortality Weekly Report (MMWR) last month. They specifically recommend the use of Gardasil, the quadrivalent HPV vaccine that targets the cancer-causing HPV strains, as well as the strains that cause genital warts. They also recommend the vaccine for use in males age 13 through 21 who have not been previously vaccinated, and indicate that males age 22 through 26 may also be vaccinated.
There are several interesting things about this recommendation. First, the quadrivalent Gardasil vaccine is chosen over the alternative bivalent vaccine, Cervarix. The obvious reason for this is because the quadrivalent vaccine gives immunity against the type 6 and 11 HPV that cause up to 90% of genital warts. As a family physician and a parent of a male child, this alone would be enough reason for me to immunize my son against HPV. Despite this significant benefit of the vaccine, most of the data considered in this decision-making process was based on risk reduction of the more serious consequences of HPV 16 and 18 infection. These can include anal intraepithelial neoplasia, various epithelial head and neck cancers and penile cancer.
The MMWR article discusses the burden of cancer disease in males, as a result of HPV infection. The article states that of the approximately 22,000 HPV 16 and 18 associated cancers in the U.S. each year, approximately 7,000 are in males. Many of these are oropharyngeal and anal cancers. The incidence of new cases of genital warts each year in the U.S. among sexually active males is estimated at 250,000.
The MMWR article also addresses the efficacy of the quadrivalent vaccine in inducing adequate immunity. The efficacy in inducing antibodies against all four strains of genital warts was almost 90% in one large study. The reduction in the incidence of developing genital warts in the population who received at least one dose of vaccine was estimated at 68%. A subset of men in this study group who were immunized, and who have sex with other men, was looked at separately. Their risk for developing anal epithelial neoplasia related to HPV 6 and 11 was reduced by approximately 50%. It seems reasonable to assume that if straight men receive this vaccine, they will be less likely to carry the HPV 16 and 18 strains, and thus will be less likely to put their female partners at risk for cervical dysplasia and cervical cancer.
Is the HPV vaccine safe for boys? The safety data for the HPV for vaccine is very strong. The most common adverse events were mild or, at most, moderate, and were usually injection site swelling, with many fewer cases of headache and fever. Approximately 40 million doses of HPV vaccine have been used the United States in the first five years since licensure, and no increase in incidence of any serious consequences have been noted. Don’t believe the ranting of fanatics who badmouth the HPV vaccine, along with many other safe and effective vaccines. Fainting after getting the shot seems to be the most serious adverse outcome and doesn’t seem to be any higher than with any other shot.
What is the cost of the HPV vaccine? At approximately $130 per dose, and $390 per three-shot series, this vaccine is quite spendy. Probably the strongest argument against routine HPV vaccination of males is its cost. Any discussion of the benefits of immunization of males depends greatly on the incidence of immunizations of females. The rate of immunization of females in the U.S. remains much lower than ideal with an estimated 47% of females age 13 through 17 having received at least one dose, and only 32% having received all three doses. If a very high percent of females was immunized, the risk of males who have female sexual partners acquiring genital warts would be considerably lower. Given the current high prevalence of the HPV virus, it seems reasonable to assume that, for some time now, heterosexual young men will continue to have a significant chance of acquiring HPV virus.
Why give HPV vaccine to such young boys? Parents may ask “why immunize my 11 or 12-year-old boy who, I’m quite certain, won’t be sexually active for many more years?” The answer is several-fold. The first is that the highest efficacy for prevention of genital warts is in pre-sexual persons. The second is that children immunized between ages 9 and 15 had higher antibody titers and, therefore, presumably better immunity than those vaccinated from age 16 through 26. The bottom line is that boys vaccinated prior to first sexual contact and before age 15 have the best chance of immunity to genital warts and avoiding contracting them.
So what should you do for your boy? My recommendation is that you get your son immunized at a relatively young age; certainly before age 15, but ideally with his pre-sixth-grade immunizations around age 12. Why so early? Why not? is really the better question. The immunity seems to be long-lasting, and getting the vaccine for your child while you still have considerable influence over their health care decisions, while you’re still confident that their pre-sexual, and while they’re in the routine of getting other immunizations just seems to make the most sense to me. So is HPV for boys a good choice? My recommendation: A strong yes.