HPV: Time To Vaccinate The Lads As Well!

5. December 2017
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Eleven years after the launch of the first HPV vaccine, it's time to take stock. As the number of protected women rises slowly but surely, men become the new risk group. Experts are calling for comprehensive vaccination of both sexes.

Around 80 percent of all people become infected during their lifetime with human papilloma viruses (HPV). Depending on the genotype, HPV triggers the growth of benign or malignant tumours. “Low risk” virus types such as type 6 and 11 lead to condylomata acuminata, better known as genital warts. In contrast, scientists see an association between “high risk” viruses and cancers such as cervical cancer, rectal carcinoma and oropharyngeal carcinoma. These types include 16, 18, 31 and 45. Doctors have long focused on women and simply disregarded men.

Leaving the lads unvaccinated: “negligent”

Background information: experts from the Standing Vaccination Commission (STIKO) at the Robert Koch Institute advise doctors to vaccinate only girls between the ages of nine and fourteen against HPV. “One argument for girls’ vaccination has always been to lower the HPV burden of sexually active young women to such an extent that the young men, as sexual partners of the vaccinated women, can no longer be infected,” Professor Kurt Miller comments. He is director of the Department of Urology at the Charité in Berlin. “However, this herd protection only works if more than 85 percent of young girls are covered by the HPV vaccine”. In reality, vaccination rates remain below 40 percent.

A further limitation to herd protection comes in the form of men who have sex with men (MSM). Miller’s conclusion: “Since the penis is the main transmitter of HPV, leaving lads unvaccinated is negligent”.

The male sexual organ seems to play a particular role, although there is still need for research here. If men suffer from a foreskin constriction (phimosis), they are more likely to get penile carcinoma. This cancer is also associated with HPV. “Circumcised men have a lower risk of developing penile cancer, which is why penile cancer is less common in countries or cultures where circumcision is common in childhood”, Professor Dr. Oliver Hakenberg explains. He heads the Department of Urology and Polyclinic at the University of Rostock (Germany).

Blow-job with consequences

This is not just about lesions on the penis. “The incidence of HPV-associated oropharyngeal carcinoma has increased since the 1980s and has doubled in the last two decades especially among men”, Gypsyamber D’Souza, from the John Hopkins Bloomberg School of Public Health in Baltimore, says. She has evaluated data on 13,089 individuals between 20 and 69 years of age. The basis of her work was data from NHANES (National Health And Nutrition Examination Survey). Available data was derived from 9,425 subjects aged 20 to 59 on their sexual practices. Data from cancer registries were added to this.

D’Souza and colleagues found oncogenic HPV DNA in the mouth and throat area in 3.5 percent of all adults between 20 and 69 years of age. Women who had oral sex with a maximum of one male had the lowest prevalence. Only 1.8 percent of all female smokers and 0.5 percent of all female non-smokers were infected. The level increased to a maximum of 3.0 percent for those with ten or more sex partners.

The study showed significantly higher levels in men (MSM). For those who had never had oral sex with any other man or only with one at most, prevalence was 1.5 percent. For those with a maximum of four oral sex partners this figure was 4.0 percent (non-smokers) or 7.1 percent (smokers). For those who had traded blow-jobs with five or more men the figure came to 7.4 (non-smoker) or 15.0 percent (smoker).

High-risk viruses more common in men

Kalyani Sonawane from the University of Florida, Gainesville, arrived at similar results. She recently presented numbers for male Americans, whereby the database used was also derived from NHANES. With regard to oral HPV infections Sonawane provided data showing a prevalence of 11.5 percent for males and 3.2 percent for females. That’s equivalent to 11 million men and 3.2 million women across the US. High-risk genotypes were more common in men than in women (7.3 versus 1.4 percent).

For men and women who had same-sex sexual partners, the prevalence of high-risk HPV viruses was 12.7 and 3.6 percent, respectively. If men had had oral sex with several other men, prevalence was even as high as 22.2 percent. The likelihood of oral HPV infection from high-risk viruses was most prevalent among black participants, among those who smoked more than 20 cigarettes a day, consumed marijuana or had a large number of different sexual partners.

What does this knowledge bring?

Doctors are currently able to do very little with these studies on risk. “At present there are no tests available that could be used for the early detection of oropharyngeal carcinoma”, Carole Fakhry from the John Hopkins University School of Medicine explains. For risk patients, no conclusions can possibly be made about future cancers, she says. Alternatively, HPV vaccines are an option, provided they cover the widest possible range of infections.

Since 2006, vaccines have been available for preventive use. The dual vaccine contains type 16 and 18 antigens. With the triple vaccine the antigens contained are for HPV 6, 11, 16, and the nine-fold vaccine includes 6, 11, 16, 18, 31, 33, 45, 52 and 58.

Condoms protect regardless of sexual practice, this being a matter beyond question. Those who abstain from oral sex also minimise their risk. This is especially true for MSMs and for women who gratify men orally. Thus far, little attention has been paid to how men are affected if they gratify women orally.

Moreover, one aspect must not be forgotten: around 70 to 80 percent of all people are infected with HPV during their lifetime. In almost all cases, the immune system succeeds in repelling infections. Only persistent oncogenic viruses increase the risk of cancer. And this is exactly where vaccinations take effect, before the first infection.

Vaccination for everyone

The reasoning here cannot be challenged. In women, the effect of vaccinations is slowly becoming apparent, as Yvonne Deleré from the Robert Koch Institute reports. Between 2010 and 2012 she recruited exactly 787 women from 20 to 25 years of age. All participants had to provide information about themselves as well as providing a cervical smear. Of these, 512 were not vaccinated against HPV.

In the unprotected population, HPV prevalence was 38.1 percent, regardless of virus type. The most common genotype identified by Deleré was HPV 16 (19.5 percent). The prevalence of having at least one high-risk type was 34.4 percent. Among the 223 vaccinated women, HPV 16/18 levels were significantly lower compared to unvaccinated subjects (13.9 versus 22.5 percent).

“We show that there is high prevalence of high-risk HPV genotypes among non-vaccinated women in Germany, one which can potentially be prevented by vaccination”, Deleré summarises in relation to her results. The likely effects of vaccination on HPV prevalence have been observed for women who have been vaccinated at a younger age, she says. “This finding reinforces the recommendation to vaccinate girls in early adolescence”, the lead author concludes.

Doctors should respond now

Men benefit as well. Several studies (among others Giuliano et al., Palefsky et al.) show that commercial HPV vaccines at the very least protect men from getting genital warts and precursors of penis and anal cancer. “STIKO­ is investigating the current existing evidence of HPV­ vaccination of boys, in order to reassess the ­reco­mmendation made to introduce routine vaccination”, the Robert Koch Institute states. An exact timetabled plan is not yet at hand.

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2 comments:

Guest
Guest

Love to see the proof of efficacy before calling this “negligent”.

#2 |
  1
Marc Van Wijk
Marc Van Wijk

It seems men are the next interesting customers group…

#1 |
  1


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