As the human papillomavirus (HPV) vaccine is now recommended for males, a reliable, comprehensive HPV knowledge measurement tool which addresses issues relevant to males is needed. We aimed to replicate, validate and test the comprehensiveness of an existing general HPV and an HPV vaccination knowledge scale in English and French. We also measured parental HPV knowledge and changes over time. An online questionnaire was administered in February (Time 1; T1) and November 2014 (Time 2; T2) to a nationally representative sample of Canadian parents of boys. Dimensionality, internal consistency and model fit were evaluated at both time points and separately in English and French sub-samples. Differences in knowledge scores were measured. Analyses were performed on 3117 participants at T1 and 1427 at T2. The 25-item HPV general knowledge and an 11-item HPV vaccination scale were unidimensional, showed high internal consistency (α>0.87, α>0.73) and had good model fit. Both general HPV and vaccine-specific knowledge significantly increased over time in both languages, but remained low at T2, with only about half of the items being answered correctly. Correct responses at T2 are best explained by correct responses at T1, with some small changes from 'Don't know' at T1 to correct at T2. The extended general and vaccine-specific knowledge scales are valid, reliable and comprehensive, and could be used among parents of boys, in both English and French. Educational interventions could target specific knowledge gaps and focus on providing information rather than correcting misconceptions.

Objective: The study's objective was to examine parents' reasons for their decision to vaccinate their 9–16‐year‐old sons with the human papillomavirus (HPV) vaccine.Methods: Using the precaution adoption process model (PAPM), parents were classified according to one of six stages of decision making: unaware, unengaged, undecided, decided not to vaccinate, decided to vaccinate, or vaccinated. Parents responded to an open‐ended question: ‘What would influence your decision to have your son vaccinated or not against HPV?’Results: Three thousand one hundred and seventeen parents provided 2,874 interpretable narrative responses that were coded using thematic content analyses. The majority of parents were in the earlier precaution adoption process model stages, that is, unaware that the HPV vaccine could be given to boys (57.0%), unengaged (20.9%), or undecided (9.1%). Needing more information, vaccine cost, risks associated with vaccination, and wanting a doctor's recommendation influenced these earlier‐staged parents' decisions. Parents who decided not to vaccinate their sons (6.8%) reported their decision was due to the risks, insufficient research, lack of confidence in vaccines, and/or no need for the vaccine (as their sons are not sexually active and/or too young). Parents who had decided to vaccinate their sons (5.0%) or who had vaccinated their sons (1.1%) reported that their decisions were based on protecting their sons' health and preventing disease.Conclusion: There are important differences in the factors that influence parents' decision depending on where they are along the decision‐making trajectory. Assuring that parents are well informed about the importance of male vaccination, reducing vaccine cost, accurately communicating vaccine safety, and improving patient–provider communication may augment vaccine coverage and prevent HPV‐associated cancers in Canada. Copyright © 2015 John Wiley & Sons, Ltd.

Background: Achieving optimal human papillomavirus (HPV) vaccine uptake can be delayed by parents’ HPV vaccine hesitancy, which is as a multi-stage intention process rather than a dichotomous (vaccinated/not vaccinated) outcome. Our objective was to longitudinally explore HPV related attitudes, beliefs and knowledge and to estimate the effect of psychosocial factors on HPV vaccine acceptability in HPV vaccine hesitant parents of boys and girls. Methods: We used an online survey to collect data from a nationally representative sample of Canadian parents of 9–16 years old boys and girls in September 2016 and July 2017. Informed by the Precaution Adoption Process Model, we categorized HPV vaccine hesitant parents into unengaged/undecided and decided not. Measures included sociodemographics, health behaviors and validated scales for HPV and HPV vaccine related attitudes, beliefs and knowledge. Predictors of HPV vaccine acceptability were assessed with binomial logistic regression. Results: Parents of boys and girls categorized as “flexible” hesitant (i.e., unengaged/undecided) changed over time their HPV related attitudes, behaviors, knowledge and intentions to vaccinate compared to “rigid” hesitant (i.e., decided not) who remained largely unchanged. In “flexible” hesitant, greater social influence to vaccinate (e.g., from family), increased HPV knowledge, higher family income, white ethnicity and lower perception of harms (e.g., vaccine safety), were associated with higher HPV vaccine acceptability. Conclusions: HPV vaccine hesitant parents are not a homogenous group. We have identified significant predictors of HPV vaccine acceptability in “flexible” hesitant parents. Further research is needed to estimate associations between psychosocial factors and vaccine acceptability in “rigid” hesitant parents.

Background: High COVID-19 vaccine uptake is crucial to containing the pandemic and reducing hospitalizations and deaths. Younger adults (aged 20-39 years) have demonstrated lower levels of vaccine uptake compared to older adults, while being more likely to transmit the virus due to a higher number of social contacts. Consequently, this age group has been identified by public health authorities as a key target for vaccine uptake. Previous research has demonstrated that altruistic messaging and motivation is associated with vaccine acceptance. Objective: This study had 2 objectives: (1) to evaluate the within-group efficacy of an altruism-eliciting short, animated video intervention in increasing COVID-19 vaccination intentions amongst unvaccinated Canadian younger adults and (2) to examine the video’s efficacy compared to a text-based intervention focused exclusively on non-vaccine-related COVID-19 preventive health measures. Methods: Using a web-based survey in a pre-post randomized control trial (RCT) design, we recruited Canadians aged 20-39 years who were not yet vaccinated against COVID-19 and randomized them in a 1:1 ratio to receive either the video intervention or an active text control. The video intervention was developed by our team in collaboration with a digital media company. The measurement of COVID-19 vaccination intentions before and after completing their assigned intervention was informed by the multistage Precaution Adoption Process Model (PAPM). The McNemar chi-square test was performed to evaluate within-group changes of vaccine intentions. Exact tests of symmetry using pairwise McNemar tests were applied to evaluate changes in multistaged intentions. Between-group vaccine intentions were assessed using the Pearson chi-square test postintervention. Results: Analyses were performed on 1373 participants (n=686, 50%, in the video arm, n=687, 50%, in the text arm). Within-group results for the video intervention arm showed that there was a significant change in the intention to receive the vaccine (χ21=20.55, P<.001). The between-group difference in postintervention intentions (χ23=1.70, P=.64) was not significant. When administered the video intervention, we found that participants who had not thought about or were undecided about receiving a COVID-19 vaccine were more amenable to change than participants who had already decided not to vaccinate. Conclusions: Although the video intervention was limited in its effect on those who had firmly decided not to vaccinate, our study demonstrates that prosocial and altruistic messages could increase COVID-19 vaccine uptake, especially when targeted to younger adults who are undecided or unengaged regarding vaccination. This might indicate that altruistic messaging provides a “push” for those who are tentative toward, or removed from, the decision to receive the vaccine. The results of our study could also be applied to more current COVID-19 vaccination recommendations (eg, booster shots) and for other vaccine-preventable diseases. Trial Registration: ClinicalTrials.gov NCT04960228; https://clinicaltrials.gov/ct2/show/NCT04960228