What influences parents to vaccinate (or not) their sons with the Human Papillomavirus (HPV) vaccine: an examination of HPV vaccine decision-making changes over time : Journal of Psychosocial Oncology Research and Practice

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Original Article

What influences parents to vaccinate (or not) their sons with the Human Papillomavirus (HPV) vaccine: an examination of HPV vaccine decision-making changes over time

Zhu, Patricia∗,†,∗; Perez, Samara†,‡,§; Griffin-Mathieu, Gabrielle; Tatar, Ovidiu†,¶; Rosberger, Zeev∗,†,§,||

Author Information
Journal of Psychosocial Oncology Research and Practice: January-March 2022 - Volume 4 - Issue 1 - p e068
doi: 10.1097/OR9.0000000000000068
  • Open


1 Introduction

The Human Papillomavirus (HPV) is the most common sexually transmitted infection (STI),[1] and is responsible for 29% of all infection-related cancers and 4.5% of all cancers worldwide.[2–4] Importantly, HPV-related cancers affect both men and women. Cancers attributable to HPV include cervical, vaginal/vulvar, anal, penile, and oropharyngeal.[2] HPV can also cause genital warts, which can negatively impact an individual's quality of life.[5] In Canada, 3800 Canadians are diagnosed with an HPV-related cancer each year, and this number is expected to increase to 6600 by 2042.[6]

HPV vaccines have significantly impacted the prevention of pre-cancerous lesions and genital warts,[4,7–12] garnering the endorsement and recommendation from public health institutions both in Canada and worldwide for HPV vaccination for females and males.[13–15] These vaccines are most effective when given prior to sexual debut, which can be defined as any partnered sexual activity involving genital contact. In Canada, HPV school-based programs begun for girls in grades 4 to 7 in 2007 and were extended to boys in the same grades five years later in 2012. It is only since 2018 that all provinces and territories have implemented school vaccinations for boys in grades 4 to 7. Because vaccination programs are provincially organized, Canada does not have national data on the overall uptake of the HPV vaccine. Recent provincial data from 2017 to 2018 and 2018 to 2019 show that the HPV vaccine uptake rate for boys ranged from 57% to 82%, and the uptake rate for girls ranged from 62% to 86% depending on the province.[16] These rates are still well below the target rate of 90% set by Canadian public health authorities. Further, the HPV vaccine was initially recommended for females to prevent cervical cancer,[17] resulting in many parents being unaware that the HPV vaccine is also recommended for males.[18] This has prompted research to understand the barriers to HPV vaccination among boys.

Because the vaccine is administered at a young age, parents play a crucial role in the HPV vaccination decision-making process. Previous research examining the factors for HPV vaccine acceptance or refusal in parents of boys have found that the perceived risk of acquiring HPV, perceived benefits of the HPV vaccine, social norms/influence of others, and frequent/open parent-child communication are associated with vaccine acceptance.[19,20] In contrast, perceived barriers (eg, fear of side effects, concerns about vaccine safety), lack of HPV and HPV vaccine knowledge, general anti-vaccination attitudes, religious/cultural beliefs, young age of one's son, and concerns that the HPV vaccine may result in risky health behaviors (eg, early onset of sexual activity, promiscuity) were associated with vaccine refusal.[19] Additionally, qualitative studies have found that stigma (eg, believing that it is a girl's vaccine, negative connotations of STIs), conflicting messaging about HPV vaccines (eg, availability of the vaccine for boys, age of vaccination), and health care system barriers (eg, missed work/school for multiple doses, out-of-pocket costs) have contributed to parents’ reluctance to vaccinate their sons against HPV.[21] Trusting health care providers (HCPs) and receiving a strong recommendation, protection against cancer and genital warts, and altruistic motivations promoted parents to accept the HPV vaccine for their son.[21]

The Precaution Adaption Process Model (PAPM) is a multistage theory model that is used to quantify individuals’ decision-making process. To our knowledge, there have been no qualitative studies that investigated reasons for why parents changed their decision over time about getting the HPV vaccine (or not) for their sons.

Our research team surveyed a nationally representative sample of Canadian parents of boys aged 9 to 16 and the PAPM to examine the psychosocial predictors associated with parents’ specific decision-making stages. At both time points (February and November 2014), perceiving a higher influence of others and a higher risk of HPV increased the odds of being in the decided to vaccinate, whereas a higher perception of harms of the vaccine increased the odds of being in the decided not to vaccinate group.[20] Using the first time-point data, we also examined parents’ reasons for their decision regarding HPV vaccination using thematic content analysis and found that risks associated with the vaccine, lack of research on the vaccine, and no need for the vaccine were the most commonly cited reasons by parents of boys who decided not to vaccinate their sons.[18] For parents who decided to vaccinate or vaccinated their sons, protection for their son and doctor's recommendation were the most commonly cited reasons for vaccine acceptance.[18]

Using qualitative methods, the primary aim of this study is to provide a more comprehensive and nuanced interpretation of our quantitative results by analyzing responses provided by parents to open-ended questions related to the motives that influence a change in their decision-making with respect to HPV vaccination for their sons over time. This method allows us to understand parents’ own unique reasonings and perspectives underlying the change in their decision. Additionally, this study examines psychosocial factors (socio-demographics, knowledge, attitudes, and beliefs) associated with parents who moved to decided not to vaccinate and those who moved to decided to vaccinate or vaccinated over time. This offers an additional quantitative perspective to compare with the responses that participants provided for the open-ended questions, allowing us to identify any similarities or inconsistencies between the 2 perspectives.

2 Methods

2.1 Sample and participant recruitment

The study sample consisted of Canadian parents of at least one son aged 9 to 16 years living in their household (hereafter referred to as parents). A detailed study protocol and methodology can be found elsewhere.[22] To summarize, Leger, a polling and market research firm with a national panel of 400,000 Canadians across 10 provinces, was used to collect online survey data from 3784 parents at baseline (Time 1, T1, February 2014), and 1608 parents at the 9 months’ follow-up (Time 2, T2, October–November 2014). To evaluate the national representativeness of our sample, sociodemographic factors (eg, province, education, religion) were compared with census data from Statistics Canada 2011. The response rate (calculated based on the completion by parents who initiated the questionnaire, n = 5733 at T1 and n = 1999 at T2) was 66.0% at T1 and 80.4% at T2. After data cleaning, we analyzed 3117 responses at T1 and 1427 responses at T2. At the time of data collection, Prince Edward Island was the only province that had school-based HPV vaccination program available for boys.

2.2 Measures

The main measures used in the present study were 2 open-ended items to identify parents’ reasons for changing their decision. These 2 items are described in detail below. In addition, we assessed parents’ sociodemographics, PAPM stage at T1 and T2, and HPV and HPV vaccine knowledge at T2, and administered the Human papillomavirus Attitudes and Beliefs Scale (HABS) at T2.

2.2.1 Sociodemographics

Parents answered items about their sex, language, marital status, household income, education, religion, nationality, ethnicity, their age, and the age of their son.

2.2.2 PAPM stage

The PAPM is a theoretical framework used to identify individuals’ nominal stages of decision-making regarding health behaviors. In the context of HPV vaccination, parents can be classified into 1 of 6 PAPM stages: unaware (stage 1—unaware that the vaccine can be given to boys), unengaged (stage 2—aware that the vaccine can be given to boys but have not considered it), undecided (stage 3—considered vaccinating their son but are undecided), decided not to (stage 4—decided not to vaccinate), decided to (stage 5—decided to vaccinate), vaccinated (stage 6—their son has already received the vaccine). Although PAPM is a stage theory, people can skip stages if certain factors influence them to take action sooner. For example, a parent who was unaware at T1 could become vaccinated at T2 if they get the vaccine for their son following a doctor's recommendation.

Parents’ self-reported PAPM stages were measured by asking: “Which of the following best describes your thoughts about the HPV vaccine concerning your son?” Six response options were provided based on the categories of the PAPM. Since we are interested in the reasons and factors that are associated with parents who moved stages, the analyses for this study focused on parent's data from Time 2, specifically those who moved from Time 1 to decided to, decided not to, and vaccinated.

2.2.3 Reasons for a PAPM stage transition

Parents who moved from any initial stage at Time 1 to decided not to vaccinate, decided to vaccinate, and vaccinated at Time 2 were asked 2 open-ended questions to identify their reasons for changing their decision: “What factors influenced your decision to have your son vaccinated or not against HPV?” and “What occurred since February that changed your opinion concerning the HPV vaccine for your son?”

2.2.4 HPV and HPV vaccine knowledge

Parents’ general knowledge (GK) of HPV and the HPV vaccine knowledge (VK) were measured using a validated scale.[23] For each item, parents could answer “True,” “False,” or “Don’t know.” GK and VK scores were calculated by assigning one point for the correct answer and zero points for incorrect or “Don’t know” answers. A total score for each parent was then computed ranging from 0 to 23.

2.2.5 HABS

This validated scale consists of a total of 46 items about attitudes and beliefs toward HPV grouped into 9 factors: benefits (10 items), threat (3 items), influence (8 items), harms (6 items), risk (3 items), affordability (3 items), communication (5 items), accessibility (4 items), and general vaccination attitudes (4 items).[24] Each item within a factor was evaluated using a 7-point Likert scale where 1 = strongly disagree, 4 = neutral, and 7 = strongly agree. A mean score for each factor was calculated for each parent.

2.3 Qualitative analysis

In the process of content analysis, 3 of the authors (PZ, SP, GGM) individually coded the responses first. Coding discrepancies were resolved via conference call discussions and by consulting with the senior researcher (ZR). These responses were deductively analyzed based on factors (categories) from the HABS (eg, benefits, harms, risk, among others). However, as not all responses could not be categorized using the deductive approach, we created new categories inductively through an iterative process of reading the qualitative data multiple times. The new categories were discussed with the research team (OT, ZR) to ensure comprehensiveness and clarity. Responses to the 2 open-ended questions were combined. We summarized the data numerically by counting the responses in each category and reported frequencies for each category. Fleiss kappa was used to assess inter-rater reliability between the 3 coders for the open-ended questions.[25]

2.4 Quantitative analyses

We used the Pearson χ2 test of independence to determine the relationship between categorical sociodemographic factors in parents who moved to decided not to vaccinate, or decided to vaccinate. For statistically significant relationships (P < .05), Cramer V effect sizes were reported. For tests with degrees of freedom (DF) equal to 1, we interpreted V = .1 as a small effect, V = .3 as a medium effect, and V = .5 as a large effect.[26] For tests with DF equal to 2, we interpreted = .07 as a small effect, V = .21 as a medium effect, and V = .35 as a large effect.[26] Independent sample t-tests were performed for ages of the son and parent, knowledge (GK and VK) and each of the 9 HABS factors between parents who moved to decided not to vaccinate and parents who moved to decided to vaccinate. Bonferroni corrections were made to modify the P values for the HABS factor comparisons (P < .05/9 = .006; corrected for 9 pairwise comparisons). For statistically significant differences between the two groups (P < .006), Cohen d effect sizes were reported. We interpreted d ≤.2 as small, d = .5 as medium, and d ≥.8 as a large difference.[27]

3 Results

Of the 1427 parents who completed the survey both at T1 and T2, 118 parents moved to decided not to vaccinate, 125 moved to decided to vaccinate, and 9 moved to vaccinated. As parents who moved to vaccinated were a small group (n < 10), they were combined with parents who decided to vaccinate in the subsequent analyses and will be referred to as the decided to vaccinate group (n = 134). There were no parents who decided not to vaccinate at T1 that moved to decided to vaccinate or vaccinated at T2, and 15 parents who decided to vaccinate at T1 moved to decided not to vaccinate at T2 (see Table 1 for full results).

Table 1 - Number of parents in each PAPM stage at T1 and T2 in the subsample of those who moved to decided not to vaccinate, decided to vaccinate, or vaccinated at T2.
PAPM stage No. of parents at T1 No. of parents at T2
Unaware 129 0
Unengaged 62 0
Undecided 46 0
Decided not to vaccinate 0 118
Decided to vaccinate 15 125
Vaccinated 0 9

3.1 Socio-demographics

At T2, 67.8% of the parents were female and 32.2% were male; 21.1% completed elementary or school and 79.1% completed college or university; 17.7% were single or separated/divorced and 82.2% were married or common law; 40.7% had a household income of <$79,999 and 48.8% had a household income of >$80,000; 66.9% were religious and 31.1% were not religious; 88.% were born in Canada and 11.5% were not born in Canada; and 89.7% were White and 9.3% were other ethnicities. T1 and T2 samples had no significant differences except for the number of parents from 2 provinces and language. At T2, there were significantly more parents from Quebec and fewer parents from Saskatchewan, and there were fewer English-speaking parents and more French-speaking parents; however, the effect sizes for both differences were small. Comparing T1 and the Statistics Canada samples, there were 14 statistically significant differences; however, none had a large effect size. A more detailed description of the study population can be found elsewhere.[22]

Among those who moved to decided to vaccinate (n = 134), there was a higher proportion of English speakers (71.6%) than French speakers (22.4%), χ2 = 22.18, P < .05, V = .297. Among those who moved to decided not to vaccinate, there was a higher proportion of parents who completed college/university (75.4%) than parents who completed elementary/high school (24.6%), χ2 = 7.02, P < .05, V = 0.167. While these results are significant, the effect sizes remain small (V < .3). There were no other significant differences in sociodemographics between the 2 groups (Table 2).

Table 2 - Sociodemographics variables for parents who moved to decided not to vaccinate and decided to vaccinate.
Decided not to vaccinate (n = 118)n (%) Decided to vaccinate (n = 134)n (%) P
 Female 94 (79.7) 93 (69.4)
 Male 24 (20.3) 41 (30.6)
Language .000
 English 53 (44.9) 96 (71.6)
 French 60 (50.8) 30 (22.4)
 Other 54 (4.2) 8 (6.0)
Marital status .399
 Single 24 (20.3) 22 (16.4)
 In a relationship§ 93 (78.8) 112 (83.6)
Household Income (before taxes) .299
 <$79,999 59 (50.0) 54 (40.3)
 ≥$80,000 48 (40.7) 66 (49.3)
Education .008
 Elementary or high school 29 (24.6) 54 (40.3)
 College/university 89 (75.4) 80 (59.7)
Religion .334
 Religious 85 (72.0) 86 (64.2)
 No faith 32 (27.1) 45 (33.6)
Nationality .843
 Born in Canada 104 (88.1) 117 (87.3)
 Not born in Canada 14 (11.9) 17 (12.7)
Ethnicity .469
 White 109 (92.4) 119 (88.8)
 Other 9 (7.6) 14 (10.4)
Mean SD Mean SD
Son's age 12.4 2.3 12.6 2.2 .55
Parent's age 43.8 6.6 45.2 6.6 .09
Not all sums add up to 100% because parents were given the option “I prefer not to answer” on some questions.
English includes a small subsample of parents who self-reported a combination of English and other language (3.2%).
“Single” includes parents who self-reported as single (9.9%), separated but still legally married (1.6%), divorced (6.3%), or widowed (0.4%).
§“In a relationship” includes parents who self-reported as married (65.5%) or in a common law relationship for over a year but are not legally married (15.9%).
Other ethnicities include Aboriginal (0.4%), Black (1.6%), East Asian (5.2%), Latin/Central American (0.4%), South Asian (1.2%).Bolded P values indicate a significant difference between the decided not to vaccinate and decided to vaccinate groups.

3.2 Reasons for a change in PAPM stage

There were a total of 504 responses to the open-ended questions. A total of 58 responses were coded as uninterpretable or gave no reason for the change, for example, blank or wrote nothing/none, and were excluded from subsequent analyses. Some responses were multifaceted and coded into more than one category. There were a total of 301 codes assigned to the responses of parents who moved to decided not to vaccinate, and 293 codes assigned to the responses of parents who moved to decided to vaccinate (Table 3). The initial inter-rater reliability was high, with Fleiss kappa = .806.

Table 3 - Frequency of assignment of categories in the qualitative responses of participants who moved to decided not to vaccinate compared to parents who moved to decided to vaccinate.
Categories Decided not to vaccinate Decided to vaccinate
Benefits 0 74
Threat 20 15
Influence 19 9
Harms 90 0
Risk 0 23
Affordability 11 10
Communication 7 1
Accessibility 2 15
General vaccination attitudes 34 10
Knowledge 60 86
HCP's opinion 10 37
Age of son 17 7
Lifestyle, religion, and morality 12 0
Child's decision 11 2
Other 8 4
Total 301 293

Using deductive analysis based on the HABS, nine categories that were coded were benefits, threat, influence, harms, risk, affordability, communication, accessibility, and general vaccination attitudes. Inductive analyses revealed five new categories: knowledge, HCP's opinion, age of the child, child's decision, lifestyle/religion/morality. There was also an “other” category, which included responses that could not be captured by any of the 14 other categories, but were still valid and can further contribute to the understanding of HPV vaccine decision-making process. A full list of illustrative quotes from both parents who decided not to vaccinate and decided to vaccinate can be found in Table 4.

Table 4 - Illustrative quotes.
Decided not to vaccinate Decided to vaccinate
 Benefits NONE “I want to give [my son] the best medical care possible and if this helps him and his future sexual partners then I am all for it”“I believe that it is each individuals’ responsibility to take steps to protect their health and those of others. Vaccination is the responsible thing to do”
 Threat “I am not convinced of the importance of vaccination for this disease”“The vaccine is mainly for girls” “I do not want my son to ever suffer from warts or cancer”“My wife has HPV and had a cancer scare”
 Influence “If the government doesn’t pay for it that means that it is not necessary”“I have 3 friends who have suffered and continue to suffer from the HPV vaccine. One of which was an athlete and had a stroke and is now wheelchair bound” “His school suggested it would be a good idea”“Awareness of HPV cancer in family friends”
 Harms “Vaccine is too new, we don’t know the long term side effects.”“I am afraid that it is only a pharmaceutical lobby to make money. If the government and independent scientists approve it, I will do it.” NONE
 Risk “Most people have HPV at some time in their lives and I don’t know anyone who ever got cancer from it.” “Decreasing the risk of hi[m] developing HPV related cancers”
 Affordability “The price of the vaccine with RAMQ” “Hope government will pay”
 Communication “I spoke with him and he doesn’t want” “Discussions between his father, me, and [my son]”
 Accessibility “Multiple doses to be received”“Being too busy” “[My son's] school is offering the shot”
 General vaccination attitudes “[I] don’t believe in it at all, pharmaceuticals just trying to shove more drugs in our kids”“I do not have confidence in any vaccine” “My daughters are vaccinated”“I believe in vaccinations and if there is one that can potentially save lives then I’m all for it. The pros outweigh the cons!”
New categories
 Knowledge “I did some further research”“Bad publicity” “Public information pamphlets”
 HCP's opinion “Doctor is still very much on the fence as well”“The opinion of some physicians who think that the vaccine is too new and caused very serious problems in some young girls” “It was recommended by his doctor”“Friend who is a doctor who advised strongly in favour of it”
 Age of son “He is not sexually active and probably won’t be in the foreseeable future”“We are waiting until he is older and his body can handle it” “He is getting to an age when he may become sexually active”“My son is getting older so these questions become more important”
 Lifestyle, Religion, and Morality “The type of cancer that HPV prevents is not hereditary but acquired through lifestyle… We will just be guardians of moral for our children”“I am not for multiple sexual relationships”“Lifestyle, religious beliefs” NONE
 Child's decision “He doesn’t want it. I am not forcing him” “[My son] decided to get himself vaccinated”
 Other “He's afraid of vaccination“[My son] has Asperger” “Court orders … My decision was vetoed”
The influence of HCPs was originally part of the “Influence” category in the HABS. However, to get a more nuanced understanding of the reasons that guide parents’ decision-making regarding HPV vaccination for their sons, HCP's opinion was created as its own category.

The most commonly assigned category for moving to decided not to vaccinate was perceived harms (30%), followed by knowledge (20%), and anti-vaccination attitudes (11%). See Figure 1 for the proportion of qualitative responses assigned to each category in parents who moved to decided not to vaccinate.

Figure 1:
Proportion of qualitative responses assigned to each category in parents who moved to decided not to vaccinate.

The most commonly assigned category for moving to decided to vaccinate was knowledge (29%), followed by perceived benefits (25%), and HCP's opinion (13%). See Figure 2 for the proportion of qualitative responses assigned to each category in parents who moved to decided to vaccinate.

Figure 2:
Proportion of qualitative responses assigned to each category in parents who moved to decided to vaccinate.

3.3 Differences in knowledge scores

There was a significant difference in mean knowledge scores between the two groups for VK (Table 5). Parents who moved to who decided to vaccinate their sons had higher vaccine knowledge than parents who moved to decided not to vaccinate their sons, with a medium effect size, P < .05, d = .44.

Table 5 - HABS factor score and knowledge score means of parents who moved to decided not to vaccinate and decided to vaccinate.
Decided not to vaccinate Decided to vaccinate

Mean SD Mean SD P
HABS Factors
 Benefits 3.96 1.12 5.87 .75 .000
 Threat 5.65 1.04 6.36 .70 .000
 Influence 3.29 .91 4.95 .96 .000
 Harms 5.20 1.28 2.61 .97 .000
 Risk 3.23 1.18 5.33 1.13 .000
 Affordability 4.15 1.43 4.01 1.64 .464
 Communication 2.42 1.30 2.44 1.24 .916
 Accessibility∗∗ 4.89 1.28 5.35 1.22 .004
 General Vaccination Attitudes 3.92 1.38 6.21 .80 .000
 T2 HPV GK 14.42 4.98 15.62 4.76 .05
 T2 HPV VK∗∗∗ 6.37 2.52 7.39 2.05 .00
Indicates significance P < .006 (Bonferroni corrected) with Cohen d effect size ≥.8.Bolded P values indicate a significant difference between the decided not to vaccinate and decided to vaccinate groups.
∗∗Indicates significance P < .006 (Bonferroni corrected) with Cohen d effect size <.8.
∗∗∗Indicates significance P < 0.05.

3.4 Differences in HPV attitudes and beliefs

All factor score means, except for affordability and communication, were significantly different between the 2 groups, P < .006 (Table 5). For parents who moved to decided to vaccinate, their scores on the following factors were significantly higher than parents who moved to decided not to vaccinate: benefits (d = 2.00), threat (d = .80), influence (d = 1.78), risk (d = 1.81), accessibility (d = 0.36), and general vaccination attitudes (d = 2.04). Conversely, parents who moved to decided not to vaccinate their sons had significantly higher scores on the harms factor (d = 2.28) compared to parents who moved to decided to vaccinate. The effect sizes were large for benefits, threat, influence, risk, and general vaccination attitudes, and were medium for accessibility.

4 Discussion

To our knowledge, this is the first study using qualitative methods that examined within-person changes in parents’ reasoning for transitioning to refusing or accepting the HPV vaccine for their sons.. Using qualitative analysis methods, we found that parents who moved to decided not to vaccinate their sons indicated harms, knowledge, and negative, general anti-vaccination attitudes to be the most common reasons for vaccine refusal. In contrast, those who moved to decided to vaccinate indicated that knowledge, benefits, and HCP's opinion were the most common reasons for vaccine acceptability. Importantly, quantitative comparisons of the HABS factors between the two groups supported these results; benefits and influence scores were higher for parents who moved to decided to vaccinate, whereas the harms score was significantly higher for parents who changed to decided not to vaccinate. On average, we also found that parents who moved to decided to vaccinate scored higher on HPV vaccine knowledge. These results align with subsequent studies of parents of boys in 2016 and 2017 carried out by our research team, demonstrating that perceived vaccine benefits, social influence and harms were significantly associated with HPV vaccine intentions in “flexible” hesitant parents (ie, unengaged or undecided) over time.[28]

From our qualitative analysis, knowledge was revealed to be an important reason for facilitating movement to decided not to vaccinate and decided to vaccinate, reflecting our previous study that found HPV general knowledge to be a predictor for being in both groups.[20] However, Radisic et al[19] showed in a systematic review that knowledge about HPV and the HPV vaccine remains low among parents from both groups, which reflects the extant literature that demonstrated parents’ limited knowledge about HPV and the availability of the vaccine. Krawczyk et al[29] found that the perception of having enough knowledge may directly affect vaccination intentions. Combined with low knowledge, this may result in the Dunning-Kruger effect,[30] a bias in which people with limited knowledge overestimate their own knowledge, leading to a false sense of confidence and strong assumptions. One strategy to overcome this bias is to make people aware of their knowledge gap by providing them performance feedback. Therefore, to increase HPV vaccine uptake in boys, it is not only important to bolster parents’ confidence in their ability to make an informed decision,[29] but also to ensure that they use reliable, factual information to do so.

As the decided not to vaccinate group (“rigid hesitant”) is unlikely to change their vaccine intentions spontaneously over time,[28] it is imperative to create targeted interventions for this group in order to increase vaccine uptake. We found that people who moved to decided not to vaccinate often cited perceived harms of the vaccine as the reason for why they refused the vaccine. These findings are consistent with our previous quantitative analyses that found harms to be a predictor of being decided not to vaccinate.[20] In the present study, parents often described negative stories associated with the vaccine that elicit strong negative emotions. These stories are difficult to counteract with objective, scientific evidence[31]; thus, a more effective method of combating these perceived harms may be for provaccination parents to share more personal stories and experiences cancer prevention and successes of the HPV vaccine. It is also important for public health authorities to build trust with the public, as distrust in health authorities can be a serious impediment to vaccine uptake.[32] This can be achieved by monitoring public opinions and addressing fears and misconceptions before they escalate and become widespread. Widespread misinformation can rapidly plummet vaccination rates, as seen in examples from Ireland, Columbia, Japan, Romania, and Denmark.[33–37] In cases like these, it is crucial for public health authorities to act rapidly to minimize the spread of misinformation and to maintain the public's confidence in vaccines. Based on our results, it may be effective for public health authorities to create messages that elicit emotional responses, such as losing someone who developed an HPV-related cancer because they were not vaccinated, to appeal to this group of people who are unlikely to change their minds.

Our qualitative results showed that parents who moved to decided to vaccinate indicated that the lasting benefits of the vaccine, vaccine safety, and vaccine effectiveness (ie, benefits of the vaccine) were important reasons to consider while making a decision, which is consistent with extant literature.[38,39] Similarly, our previous quantitative study found that benefits was associated with lower odds of being decided not to vaccinate.[20] In contrast, benefits (or the lack thereof) was not cited by any parent who moved to decided not to vaccinate. Several past studies have found altruism, that is, the desire to help others without necessarily expecting personal benefit, to be related to intentions to receive a vaccine.[40–44] Therefore, emphasizing the benefits of the HPV vaccine and presenting it as a cancer prevention vaccine for not only the child, but also the child's future partner(s) would be a compelling reason for parents to decide to vaccinate their sons.

Hearing a HCP's opinion was a commonly assigned category for parents who transitioned to decided to vaccinate. This is consistent with previous quantitative research showing that HCPs’ recommendations are a strong predictor for HPV vaccination.[20,28,45–47] One study found that receiving a high-quality recommendation increased vaccine initiation (receiving at least one dose of the HPV vaccine) by 9-fold, as well as vaccine completion (receiving three doses) by three fold.[48] These findings show that it is especially important for parents to discuss HPV vaccination with their HCPs, and for HCPs to provide strong recommendations for the HPV vaccine. Our qualitative findings revealed that some parents cited HCP's opinion as a reason for moving to decided not to vaccinate their sons. This may be a reflection of low HPV knowledge among HCPs.[49] To increase vaccine uptake, comprehensive knowledge training on HPV and the HPV vaccine for HCPs may be necessary, as well as ensuring HCPs’ comfort with vaccine counseling.

Some parents believed that their son is too young and were not yet sexually active. As a result, they decided not to vaccinate their son. However, ∼ 21% to 39% of Canadian children reported experiencing their first sexual intercourse before 14 years’ old,[50] suggesting that it is around this age (or even earlier) when they begin to experiment sexually. To improve HPV vaccine uptake in boys, one important idea is to educate parents that ages 9 to 12 is the optimal time to receive the vaccine since this is before the start of any sexual activity. In contrast to older results,[51–53] our qualitative study findings do not substantiate parents being concerned about the HPV causing early sexual promiscuity or increased sexual activity, even amongst those who moved to decided not to vaccinate. There is no evidence that HPV vaccination causes riskier behaviors or higher rates of STIs,[54] and our present finding demonstrates that this is not a category expressed by Canadian parents who hesitate or refuse HPV vaccination, as the media had initially reported. Our results should be reassuring to HCPs as they do not need to address this unfounded belief for most parents, and ideas of sexual disinhibition can be put to rest. Instead, HCPs should combat HPV vaccine hesitancy by addressing concerns relating to the harms of the vaccine, while also promoting the vaccines’ benefits for cancer prevention.

The strength of this study includes using a theoretical model that presents different decision-making stages, allowing us to capture a more nuanced picture of the reasons parents considered in changing their decision about getting their son vaccinated or not against HPV. As well, this is the first study to use qualitative methods to analyze parents’ reasons for changing their decision.

There are some limitations to this study. The data were collected when the HPV vaccine was first introduced to boys in Canada; therefore, parents’ attitudes, beliefs, and knowledge on HPV and the HPV vaccine may have evolved since then, particularly amidst the COVID-19 pandemic. Using theoretical stage models, future studies are needed to examine the impact of the COVID-19 pandemic on vaccine hesitancy in general, as well as for specific vaccines such as the HPV vaccine. They use open-ended questions in our survey did not allow us to probe for more information when responses were unclear, thereby limiting the ability to collect more “rich” data and clarify ambiguous responses. For example, in the analyses of the open-ended questions, answers such as “received information” and “need more information” were both coded as “knowledge.” As a result, we cannot conclude if receiving misinformation or requiring more information was their reason for changing their decision. We also do not know if knowledge refers to HPV general knowledge or HPV vaccine knowledge. By discerning which type of knowledge plays a more important role in changing parents’ decisions, targeted messaging or interventions can be developed.

By identifying the reasons that can result in a change in parents’ decisions, our study can inform public health officials in creating more targeted messaging will help parents decide to get their sons vaccinated. Addressing knowledge gaps, highlighting the benefits of the vaccine, appealing to people's emotions, fostering trust in public health authorities, and encouraging HCPs to provide strong recommendations will be critical to achieve high vaccine uptake. Although the vaccine was initially recommended for girls, normalizing HPV vaccination for boys can help increase HPV vaccine uptake in boys and prevent deaths caused by HPV-related cancers, providing an additional method for reaching community immunity.

Conflicts of interest statement

The authors report no conflicts of interest.


The authors warmly thank the many co-investigators and students involved throughout the years. The authors further extend thanks to Christopher A. Brown, Keven Joyal-Desmarais, Leonora King, Anila Naz, and Ben Haward for their time and support.


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attitudes; beliefs; boys; cancer prevention; health decision-making; human papillomavirus; knowledge; parents; precaution adoption process model; vaccination

Copyright © 2022 The Authors. Published by Wolters Kluwer Health Inc., on behalf of the International Psycho-Oncology Society.