This meta-analysis reveals a moderate level of HPV vaccine acceptability among men (50.4 on a 100-point scale) across 22 studies totalling 8360 participants, with a wide range of acceptability (8.2–94.0) across studies. In contrast, acceptability was considerably higher (55.0–100.0) in a review of US studies focused on young women,26
although mean acceptability was not reported.
Meta-analysis results across 16 studies (n=5048) indicate the influence of positive HPV vaccine attitudes, HCP recommendation, perceived HPV risk and HPV awareness and knowledge on HPV vaccine acceptability for men. Health promotion messaging that fosters positive attitudes about HPV vaccination benefits for men, accurate HPV risk perceptions, and that enhances awareness and knowledge regarding HPV may increase the acceptability of HPV vaccination for men.
We found no significant difference in HPV vaccine acceptability between gay, bisexual and other MSM, who would benefit most from HPV4 vaccination,7
and heterosexual men. Results from the meta-analysis suggest that in addition to promoting HPV4 vaccination for all boys and young men,23
targeted messaging for young MSM to support perceived HPV vaccine benefits and effectiveness, and accurate perceptions of HPV risk may increase acceptability.
HCP recommendation, the correlate with the second highest impact on HPV vaccine acceptability after perceived HPV vaccine benefits, has been identified as an important factor in HPV vaccine acceptability for girls,26
and patient acceptance of hepatitis B vaccines.58
HCP-identified barriers to hepatitis B vaccination—lack of government reimbursement, patient non-disclosure of risk and inadequate time to assess risk59
—suggest that in addition to promoting HCP recommendation of HPV4 vaccination for boys, it is important to assess systemic and structural barriers that may impede HCP recommendation.
The impact of HPV risk perceptions, awareness and knowledge on HPV vaccine acceptability is notable given evidence of low levels of HPV knowledge and awareness among men.32
Mechanisms to foster accurate HPV risk perceptions and awareness might involve addressing the prevalence of HPV infection and its association with cancers among men, highlighting cancer prevention as a benefit of HPV vaccination for boys48
and challenging false beliefs that HPV vaccines are not relevant for men.25
Notably, out-of-pocket cost, as reported in earlier reviews,22
logistical barriers and the need for a series of injections were negatively associated with acceptability. In meta-analysis these structural barriers had a greater impact than HPV vaccine knowledge (the most often studied correlate) and effect sizes equal to behavioural risk factors. In addition to tailored educational interventions government financing of HPV4 vaccination, and interventions to reduce barriers in access to vaccination may significantly increase HPV4 vaccine acceptance among men.
Finally, further research is needed to explore the negative association between partner thinks one should get the HPV vaccine and HPV vaccine acceptability, based on only two studies.24
Partner endorsement might implicate stigma and the association of HPV as a women's disease.25
Limitations to this meta-analysis include the absence of intervention studies, the relatively small number of studies and exclusion of unpublished studies, with few studies from each of several countries outside the USA. The lack of intervention studies precludes using RevMan 5 for meta-analyses; and some correlates of HPV vaccine acceptability are based on few studies. The limited number of studies in each setting precludes subanalysis by country. Additional studies overall and within each setting will help to identify possible differences in acceptability, including by healthcare systems and culture. Two studies of parental acceptance of HPV vaccines for male adolescents were included in the calculation of mean acceptability though not included in meta-analysis; given different challenges to uptake for adolescents and adults, meta-analysis of parental acceptance of HPV vaccination for boys is indicated.
Another limitation is due to the high risk of bias among the majority of studies included in the meta-analysis; this is indicative of weak study designs (ie, cross-sectional, non-random sampling) and suggests caution in generalising the results. However we used a random effects model that takes into account between-study and within-study variability, which suggests that the effect sizes approximate an appropriate mean of a distribution of effects. This meta-analysis provides a quantitative synthesis of the literature, indicating correlates of HPV vaccine acceptability and the magnitude and direction of these associations among a large sample of men across different studies.
Finally, as most of the studies reviewed were conducted before the US Advisory Committee on Immunisation Practices recommended routine HPV4 vaccination of men, levels and correlates of HPV vaccine acceptability may shift with additional post-2011 studies. However, low HPV vaccine coverage among young women in the USA and Europe since licensure in 200610
suggests the importance of synthesising available evidence on acceptability to guide evolving policy recommendations.
This meta-analysis suggests the importance of future investigations using more rigorous designs, including intervention research, to address factors that promote HPV vaccine acceptability among men. Generally lower levels of support for HPV vaccination among HCP and parents for young boys versus young girls11
and the particular need for HPV4 vaccination in gay/bisexual/MSM, indicate the importance of routinely disaggregating data by sex and sexual orientation in future investigations of HPV vaccine acceptability.
Overall, the moderate level of vaccine acceptability among men in the case of HPV, the most common STI, supports the need for evidence-informed interventions to address widespread gaps between HPV vaccine recommendations and actual use.
- A moderate level of human papillomavirus (HPV) vaccine acceptability (50.4 on a 100-point scale) was reported among 8360 men across 22 studies.
- Perceived HPV vaccine benefits and healthcare provider recommendation were the two most influential correlates of HPV vaccine acceptability among men.
- HPV vaccine cost and logistical barriers may pose significant obstacles to uptake.
- HPV vaccination campaigns targeting men should promote awareness of HPV, HPV-associated cancer risks and HPV vaccine efficacy, and healthcare providers’ recommendation of HPV vaccination for boys.