Vaccinating boys with HPV vaccine provides direct protection to boys.
Up to 90% of people encounter HPV during their lifetime. HPV infection has a causal role in the development of certain conditions that affect males, such as genital warts and cancers of the anus, penis and oropharynx (throat).
On average, 538 cases of HPV-associated cancers were diagnosed per year in Ireland during the period 2010 to 2014. Of these, one out of four (145 or 27%) were in men and three out of four (393 or 73%) were in women.
Oropharyngeal cancer accounts for 25% of all HPV-associated cancers. Cases have increased rapidly since 2014 in Ireland, mirroring international trends. Overall, 77.5% of all cases were in men, and approximately half are thought to be attributable to HPV.
Australia introduced HPV vaccination for girls in 2007 and extended the programme to include boys in 2013. This has led to a substantial and ongoing reduction in genital warts among Australian female and heterosexual male individuals, with a marked reduction seen in young individuals who received the vaccine at school. Another Australian study demonstrated reduced anal, penile, and oral quadrivalent vaccine-targeted HPV genotype prevalence in young men who have sex with men following the establishment of the gender-neutral HPV vaccination programme in Australia.
The Gardasil 9 vaccine protects against the HPV types that cause approximately 90% of genital warts and 90-95% of HPV related anal cancer. Studies have shown, there is a lower incidence of anal intraepithelial neoplasia or anal cancer, related to HPV types covered by HPV vaccine, in those who have received the HPV vaccine.
There is emerging evidence that the HPV vaccine is also effective in reducing the incidence of other cancers attributable to HPV. The results of a global study of over 18,000 HPV-related cancer specimens, suggest that the HPV9 vaccine can prevent 79% of anal, 25% of penile, 21% of oropharynx, 4% of oral cavity, and 3% of larynx cancer cases. As the HPV vaccine protects against the types of HPV that are related to HPV associated cancers and lowers the prevalence of these HPV subtypes, this may indicate a reduced risk of developing HPV associated cancers including oropharyngeal cancer.
However, for non-cervical cancers that are HPV associated, observing a reduction in incidence may take decades due to the older mean age of onset of these cancers.
Unlike cervical cancer precursors, there is no screening test available for oropharyngeal, anal or penile cancers in men. Men face a significant and increasing risk of HPV-associated disease and therefore vaccination is important for their protection.
Vaccinating boys is safe and effective
Similarly to Ireland, many countries now have gender neutral vaccination programmes, vaccinating both boys and girls including US, Australia, Switzerland, Austria, Norway, Sweden, and Canada.
HPV vaccines are similarly effective and have a similar safety and reactogenicity profile in males and females of the same age.
Similar to women, HPV vaccination in males has also been shown to provide long term protection against HPV infection.
Vaccinating boys also provides greater protection to women
A gender-neutral programme reduces spread of HPV and is likely to reduce the overall burden of HPV related malignancy sooner than would a girls only programme.
Vaccinating boys, as part of a gender neutral vaccination programme, helps achieve herd immunity and works towards elimination of vaccine preventable HPV
Randomized controlled trials have shown that gender-neutral vaccination programmes increased protection against HPV, with high coverage in males conveying significant herd effects to unvaccinated females.
One study predicted the elimination of HPV-18, 31, 33 in young adults in 20 years and the eventual elimination of HPV-16, with a high coverage gender-neutral HPV vaccination programme.
Vaccinating boys, as part of a gender-neutral programme, creates a more robust vaccination programme
A gender-neutral programme ensures that the vaccine programme is more robust in relation to potential short‐term fluctuations in uptake.
Vaccinating boys, as part of a gender neutral programme, protects vulnerable groups
Extension of the HPV vaccine programme to include boys will likely greatly improve protection against HPV infection and associated HPV‐attributable disease in vulnerable groups e.g. MSM and migrant groups. The protection of MSM can only be achieved by direct vaccination of males.