HPV vaccination of young girls has been implemented in many countries to prevent cervical cancer.
There is now increasing, albeit as yet indirect evidence, that it may also be effective in preventing HPV infection in the mouth.
There is also some evidence to suggest that boys are also protected by “herd immunity” in countries where there is high vaccine coverage in girls (over 85%).
Taken together, this may hopefully lead in a few decades to the reduction of oropharyngeal cancer.
That is well and good from a public health point of view, but only if coverage among girls is high - over 85%, and only if one remains within the covered “herd”.
It does not, however, guarantee protection at an individual level – and especially in this age of international travel – if, for example, someone has sex with someone from a country with low coverage.
It certainly does not afford protection in countries where vaccine coverage of girls is low, for example, the US where only 54.3% of adolescents aged 13 to 15 years had received two or three HPV vaccination doses in 2020.
Boys should have the HPV vaccine too
This has led several countries, including the UK, Australia and the US, to extend their national recommendations for HPV vaccination to include young boys - called a gender-neutral vaccination policy.
But having a universal vaccination policy does not guarantee coverage. There is a significant proportion of some populations who are opposed to HPV vaccination due to concerns about safety, necessity, or, less commonly, due to concerns about encouraging promiscuity.
Paradoxically, there is some evidence from population studies that, possibly in an effort to abstain from penetrative intercourse, young adults may practise oral intimacy instead, at least initially.
The coronavirus pandemic has brought its own challenges, too. First, reaching young people at schools was not possible for a period of time.
Second, there has been an increasing trend in general vaccine hesitancy, or “anti-vax” attitudes, in many countries, which may also contribute to a reduction in vaccine uptake.
As always when dealing with populations and behaviour, nothing is simple or straightforward.
Hisham Mehanna, Professor, Institute of Cancer and Genomic Sciences, University of Birmingham
This article is republished from The Conversation under a Creative Commons license.
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