A recent announcement is likely to generate a lot of controversy. The Advisory Committee on Immunization Practices of the CDC has recommended that boys and young men be vaccinated against human papillomavirus (HPV). Previously the guidelines said boys “could” be given the HPV vaccine. Now they have recommended that boys age 11 to 12 “should” be vaccinated, as well as boys age 13 to 21 who have not already had the full series of 3 shots. The vaccine can also be given to boys as young as 9 and to young men age 22 to 26.
The vaccine was originally promoted as a way to prevent cervical cancer. Boys don’t have a cervix, so why should they be subjected to a “girl’s” vaccine? There are some good science-based reasons:
- Boys can transmit the virus to female sex partners later in life, leading to cervical cancer in women.
- More importantly, boys themselves can also be directly harmed by the virus. It can cause genital warts, cancer of the head and neck (tongue, tonsils and throat), anal and penile cancer, respiratory papillomatosis, and giant condyloma of Buschke and Lowenstein. In rare cases, immunocompromised patients can develop epidermodysplasia verruciformis.
- HPV has even been associated with cardiovascular disease.
Some of these conditions are not common, and the most common one, genital warts, may sound trivial. But “a picture is worth a thousand words,” so here is a link to a picture of a giant condyloma of Buschke and Lowenstein as an example of what HPV can do to the unvaccinated. The picture is not pleasant. If you are squeamish, you may not want to look at it. If you can’t even stand to look at it, imagine how devastating it would be to have it appear on your own body, and how nice it would be to be vaccinated against it.
The patient is a 45 year old man who had a 1-year history of discomfort when sitting. The picture shows a cauliflower-like verrucous mass around the anus, measuring 15cm in diameter. It required surgery. These lesions are rare, destructive tumors that mostly affect men under the age of 50. They are benign, but they destroy adjacent tissue, and malignant transformation can occur. They are caused by one of the types of HPV infection that can be prevented by the HPV vaccine, HPV type 6, which was confirmed by DNA analysis in this case.
Before anyone accuses me of relying on “anecdotal” evidence, that’s not what this is: this is an illustration of a rare but serious complication of HPV infection. If it appears alarmist, maybe that’s just what science needs to get its message across, to counteract all those emotionally laden stories of patients who were allegedly hurt (“Schoolgirl, 14, Dies After Being Given Cervical Cancer Jab”) and the lies that are continually published (“HPV Vaccine Kills At Least 21 Girls So Far”). Maybe science should fight back with headlines like “Failure to Get HPV Vaccine Causes Giant Flesh-Eating Wart!”
Gardasil is a quadrivalent vaccine that protects against HPV types 16 and 18, which are responsible for about 70 percent of cases of cervical cancer, and against types 6 and 11, which are responsible for 90 percent of genital warts. It also produces some degree of cross-immunity with other HPV strains. Overall prevalence of HPV in women in the US is 26.8%, although the prevalence of the types targeted by the vaccines is only 3.4%. Most studies of HPV in men have reported a prevalence of least 20%, and some have reported much higher, up to 72.9%. Prevalence data are misleading, because they do not reflect lifetime incidence or cancer risk: many infections resolve spontaneously, and it is the persistence of certain serotypes that leads to precancerous and cancerous lesions. By one estimate, between 75 percent and 80 percent of females and males in the United States will be infected at some point in their lives. There is an alarmingly high incidence of new HPV infections in the teenage/young adult population, the group targeted for vaccines. Vaccines are most effective when given before initiation of sexual activity. These concerns have led to recommendations for legislation to facilitate vaccination.
The vaccine is very safe. Most reported side effects are mild, mainly local reactions with an occasional fainting episode. Deaths and serious adverse events after HPV vaccination have been reported to the Vaccine Adverse Event Reporting System, but none of these have been causally linked to the vaccine. The vaccine clearly works. Questions have been raised about its effectiveness, but epidemiologist Tara Smith has shown that those questions are misguided. While it is too early to document its impact on cancers or mortality, there is clear evidence that the vaccine reduces the incidence of precursors for several types of cancer. A recent study in the NEJM confirmed its effectiveness in preventing anal intraepithelial neoplasia, a precursor of anal cancer, in men who have sex with men. The rate of anal cancer is increasing in both men and women, and it is hoped that the vaccine will reverse that trend. The rate of HPV-related head and neck cancer is increasing in young men, and can also be expected to decrease with vaccination.
I won’t get into ideology, cost-effectiveness, or the pros and cons of mandatory vaccination, but the science is clear: for both sexes, the benefits of this vaccine outweigh the risks. In The New York Times Dr. William Schaffner was quoted as saying
This is cancer, for Pete’s sake… A vaccine against cancer was the dream of our youth.
I made sure my daughters got the vaccine. If I had sons, I would vaccinate them too.
*This blog post was originally published at Science-Based Medicine*