Human Papillomavirus Vaccination for Men

Advancing Policy and Practice

Peter A Newman; Ashley Lacombe-Duncan

Disclosures

Future Virology. 2014;9(12):1033-1047. 

In This Article

Future Perspective

The future of HPV vaccination for boys and young men may be productively approached through an analysis of considerations and evidence at multiple levels that will advance policy and decision-making. We believe that the analyses presented make it clear that one cannot meaningfully respond to the multiple and complex considerations involved in decisions to provide public funding of HPV vaccination only for girls and not for boys through a reductionist perspective informed predominantly by cost–effectiveness models. This does not imply that all reasonable decisions must therefore result in the inclusion of boys in publicly funded HPV vaccination programs; it does mean, however, that a failure to consider the breadth of evidence beyond reference to published cost–effectiveness models of fixed price HPV4 vaccination regimens contributes to decisions based on incomplete evidence and inaccurate assumptions.

Perhaps most importantly, on a policy level, ongoing monitoring and evaluation of evolving population health evidence from Australia, and other countries and localities that have moved to public funding of gender neutral HPV vaccination programs, will provide evidence to guide policy in other countries. Although considerations of cost–effectiveness, including various parameters used in modeling, as well as programmatic and health equity decisions, vary substantially across countries, population level evidence will substantially improve modeling predictions of health impacts of gender-neutral HPV vaccination programs.

In the case of both publicly financed HPV4 vaccination for boys and mere availability of the vaccine for boys, addressing systemic barriers to HPV4 uptake among boys and young men is a key consideration. Although population-level evidence with the recent rollout of publicly funded HPV vaccination for boys is evolving, compelling evidence exists for the influence of HCP and parents in HPV vaccine acceptability for boys and young men.[33] Similarly, healthcare system barriers beyond public funding of vaccination are both pervasive and modifiable.[33] Importantly, several school-based vaccine delivery programs, which obviate many barriers in healthcare system delivery, have resulted in high levels of HPV vaccine uptake among girls; the addition of boys, who could be vaccinated on the same day, seems unlikely to incur substantial increases in the administrative costs of vaccination.

Evidence to date in the context of healthcare system delivery suggests the importance of training HCP on the health benefits of HPV4 for boys and young men. In addition, education for HCP should address the unintended consequences of imposition of their own biases in reinforcing or generating nonacceptance of vaccination among young men and their parents, for instance, by inaccurately approaching HPV4 as a women's vaccine. Although the percentage of parents reporting that a HCP recommended HPV vaccination for their children increased in the USA from 2012 to 2013, the rate of recommendation was 50% higher for girls (64.4%) than for boys (41.6%).[32] Interventions to increase HCP competency and comfort in conducting comprehensive sexual health assessments also may promote HPV vaccine acceptability among males. More generally, closing the gap in missed opportunities for offering HPV vaccination during routine health visits and in conjunction with administration of other adolescent vaccines will support increased HPV vaccine coverage.[32] It is nonetheless important to maintain awareness of the powerful constraints on HCP posed by the high costs of HPV4 vaccine in the case of lack of public funding for universal vaccination of boys, which pervades all other HCP-related barriers to vaccination.

Systemic interventions are also necessary to support completion of the three-dose HPV vaccine series, as indicated by CDC data.[32] Interventions suggested to enhance series completion include offering the vaccine in pharmacies and retail health clinics, implementing reminder and recall systems, text message reminders and electronic medical records.[35] Clinical trials to evaluate the efficacy of HPV vaccination at younger ages, within existing pediatric vaccination schedules, also may support increased coverage as well as mitigate concerns about HPV vaccination impacting adolescent sexual behavior.[90] Importantly, to the extent two-dose HPV vaccine regimens are found to be noninferior to the three-dose regimen, this is likely to simplify uptake and significantly lower the cost of the vaccine series, thereby contributing to increased cost–effectiveness in boys and reducing logistical barriers across the board.

While many investigations have focused on enhancing HPV vaccine uptake within the context of healthcare system delivery, school-based vaccination programs have demonstrated substantial success, with high levels of uptake among girls. For example, in Scotland, a school-based vaccination program for girls aged 12–13 years, with a catch-up program for girls aged 13–17 years, was associated with three-dose uptake of 91.4% and 90.1%, respectively, in 2009 and 2010.[62,63,91,92] Among girls who had left school, 50% initiated and 30% completed vaccination within a year.[62] The program was associated with a significant reduction in HPV-16 and HPV-18 prevalence from 29.8% to 13.6% among young women attending cervical screening at age 20 years.[93]

Documented barriers at the level of public attitudes and beliefs also represent an important domain for evidence informed interventions.[35] One priority is the delinking of HPV exclusively from cervical cancer, decreasing the perception of HPV as a women's vaccine, and developing targeted interventions to enhance acceptability and uptake among men. An earlier review by Liddon et al.[34] identified the belief that the HPV4 vaccine would not directly benefit men as the primary reason why adult men, parents and HCP would not support HPV vaccination.

Barriers and facilitators of HPV4 vaccine acceptability and rollout also must be assessed in the context of broader challenges from extremist antivaccination movements. The latter have fueled vaccine hesitancy, whereby parents choose to forgo vaccination against severely debilitating childhood diseases believing discredited junk science that is pedaled over the Internet and in the media. Despite overwhelming scientific evidence, for example, that the measles, mumps and rubella vaccine does not cause autism, many people continue to cling to misinformation.[94] As a result of vaccine refusal, cases of measles have recently reached a 20-year high in the USA.[95] Substantial gains in infant immunization coverage, even in developing countries, are poorly reflected in adult HPV screening and treatment strategies.[96]

Thus interventions to promote HPV vaccine uptake among males must also address broader challenges and mistaken beliefs about vaccination in general, which might, for example, result in parents' discomfort in accepting all three doses of the vaccine series or of accepting HPV4 vaccination at the same time as other vaccines. Investigations of mental models of vaccines, and HPV vaccines in particular, among parents and young men, may help to reveal systematic misconceptions in the architecture of beliefs that fuel vaccine hesitancy. Mental models are simplified cognitive representations of complex external realities that, while incomplete, are useful in guiding decision-making and behavior; nevertheless, they also may support misconceptions and misinformation.[97,98] In the case of HPV vaccination, an understanding of mental models may provide evidence to support targeted educational interventions to dispel unwarranted fears and promote uptake.

Limited empirical research has assessed the effectiveness of interventions to increase HPV vaccine acceptability. A recent systematic review of educational interventions suggests that adolescents and young adults were more influenced than parents by these interventions.[99] However, the overarching conclusion was that there is a need for better designed studies adequately powered to evaluate the effectiveness of interventions using HPV vaccine uptake as the outcome. Additionally, most studies were conducted in the circumscribed realm of university students, revealing the need to design and assess interventions for medically underserved populations, including culturally tailored interventions for populations at disproportionate risk for HPV infection. None of the studies reviewed focused on educational interventions to increase uptake among boys,[99] an important domain for future research. It will be challenging to amend communication strategies to address HPV-driven cancers of noncervical origin given the substantial efforts to link HPV vaccination with cervical cancer prevention; however, evaluating the effectiveness of newly developed strategies can support the development of evidence-informed approaches to increasing HPV vaccine uptake among boys and men.

An interesting direction for interventions to increase HPV vaccine uptake is exploring the role of altruism, that is, being vaccinated to benefit others as well as oneself. A systematic review of parental immunization intentions and behavior indicated that while only 1%–6% of parents ranked benefit to others as their primary reason to vaccinate their children, 37% ranked benefit to others as the second most important factor in decision-making. Quadri-Sheriff et al.[100] conclude that qualitative studies are needed to explore how HCP and public health initiatives can present the idea of childhood vaccination as a benefit to others, without suggesting that parents place the well being of others above that of their own children. In two earlier studies, HPV vaccine acceptability did not differ between intervention conditions that emphasized the self-protective benefits of the HPV vaccine, partner protection, or both self-protection and partner protection, suggesting the importance of further exploring the role of altruism in HPV vaccine uptake.[101,102] In the context of vaccine hesitancy, greater understanding of altruistic vaccination may help to leverage support for vaccination by directly promoting the benefits of herd immunity.

Finally, a recent study suggests the importance of considering the nature of evidence presented in educational interventions for parents and youth in terms of its transparency and honesty. Wegwarth et al.[103] found that while actual uptake of HPV vaccine did not differ between two groups, one exposed to balanced (e.g., including the fact that most HPV types are not oncogenic) and the other unbalanced risk communication (e.g., reporting percentage reductions in cancer without presenting base rates for the incidence of various cancers), vaccination intention reliably predicted actual vaccine uptake only among those who received balanced information. Thus providing accurate and transparent information about the risks of HPV, in contrast to exaggerating the risks, does not compromise uptake and may be effective in supporting uptake through educational interventions.

A comprehensive approach, including evaluation of emerging evidence from countries that have implemented publicly financed, gender-neutral HPV vaccination programs and school-based vaccine delivery, and consideration of health equity and the benefits of universal approaches to vaccination, in addition to cost–effectiveness, will support more balanced decision-making for HPV vaccine programs and policy.

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