OBJECTIVES

We sought to identify trends in the main reasons United States parents of unvaccinated children gave for not intending to vaccinate their adolescent children against HPV from 2010 to 2020. As interventions designed to increase vaccine uptake have been implemented across the United States, we predicted that reasons for hesitancy have changed over this period.

METHODS

We analyzed data from the 2010 to 2020 National Immunization Survey-Teen, which included 119 695 adolescents aged 13 to 17 years. Joinpoint regression estimated yearly changes in the top five cited reasons for not intending to vaccinate using annual percentage changes.

RESULTS

The five most frequently cited reasons for not intending to vaccinate included “not necessary,” “safety concerns,” “lack of recommendation,” “lack of knowledge,” and “not sexually active.” Overall, parental HPV vaccine hesitancy decreased by 5.5% annually between 2010 and 2012 and then remained stable for the 9-year period of 2012 through 2020. The proportion of parents citing “safety or side effects” as a reason for vaccine hesitancy increased significantly by 15.6% annually from 2010 to 2018. The proportion of parents citing “not recommended,” “lack of knowledge,” or “child not sexually active” as reasons for vaccine hesitancy decreased significantly by 6.8%, 9.9%, and 5.9% respectively per year between 2013 and 2020. No significant changes were observed for parents citing “not necessary.”

CONCLUSIONS

Parents who cited vaccine safety as a reason for not intending to vaccinate their adolescent children against HPV increased over time. Findings support efforts to address parental safety concerns surrounding HPV vaccination.

What’s Known on This Subject:

Despite the proven safety and effectiveness of HPV vaccination, coverage falls below the Healthy People 2020 target of attaining an 80% vaccination rate. HPV vaccine hesitancy is one key factor contributing to low HPV vaccine uptake.

What This Study Adds:

We identify trends in the five most frequently endorsed reasons for HPV vaccine hesitancy among parents with unvaccinated adolescents from 2010 to 2020. Findings support efforts to enhance confidence in HPV vaccination and develop strategies for addressing HPV vaccine hesitancy.

Human papillomavirus (HPV) is the most common sexually transmitted infection in the United States,1  with an estimated 14 million new cases each year.2  Oncogenic HPV infections contribute to virtually all cases of cervical, 90% of anal, 69% of vaginal, 60% of oropharyngeal, 51% of vulvar, and 40% of penile cancers1  and second primary cancers.1,37  HPV accounts for ∼44 000 HPV-associated cancers per year: ∼25 000 among women and ∼19 000 among men.8  Although overall cancer incidence has been decreasing in the United States, HPV-associated oropharyngeal and anal cancers are some of the few cancers with increasing incidence rates.9,10  To reduce HPV-associated infections and cancer burden, the Advisory Committee on Immunization Practices recommends routine HPV vaccination for adolescents between 11 and 12 years of age; however, it is also appropriate for children aged 9 to 10 to receive the vaccination.11,12  Catch-up vaccination is recommended for males and females aged 13 to 26 years.11,12  It is estimated that the HPV vaccine could prevent >90% of HPV-attributable cancers.8  Despite the proven safety and effectiveness of the HPV vaccine, vaccination coverage remains low and falls short of the Healthy People 2030 goal of 80% completion among adolescents aged 13 to 15 years old.13  As of 2020, only 75.1% of adolescents aged 13 to 17 years had received at least 1 dose of the HPV vaccine and 58.6% had completed the series, either 2 or 3 doses based on the age of initiation.14 

One of the main reasons for suboptimal HPV vaccination coverage is parental vaccine hesitancy.15,16  Vaccine hesitancy was identified as a significant public health challenge by the World Health Organization’s Strategic Advisory Group of Experts on Immunization in 2014 and one of the top 10 health threats in the world.16  The World Health Organization’s Strategic Advisory Group of Experts on Immunization defines vaccine hesitancy as “the reluctance or refusal to vaccinate despite the availability of vaccines,” which may “reverse the progress made in tackling vaccine-preventable diseases.”16  Adolescent vaccination practices are primarily driven by their parent/guardian’s decision-making, thus understanding the reasons for parental/guardian HPV vaccine hesitancy may inform interventions to improve overall vaccination uptake.17  In the years after the release of the HPV vaccine, primary barriers to HPV vaccination voiced by parents included lack of provider recommendation and lack of knowledge along with concerns about cost, the newness of the vaccine, and potential effects on child sexual behavior.18  More recent studies suggest reasons for parental HPV vaccine hesitancy may be changing.17,1921  For example, a study examining reasons parents did not intend to vaccinate their adolescent for HPV over the 9-year period from 2008 to 2016 revealed an increase in safety concerns and lack of school entry requirements, but a decrease in lack of provider recommendation, lack of knowledge, and statements about their child not being sexually active.22 

As provider- and community-based interventions to increase HPV vaccination coverage have been implemented across the United States,2325  it is possible that parents’ primary reasons for HPV vaccine hesitancy have changed over the years, especially after 2016. Nevertheless, little research has investigated this possibility. Therefore, the current study examined whether US parents’ top five reasons for not intending to vaccinate their adolescent children against HPV changed from 2010 to 2020. Findings from this study could be critical to developing tailored and targeted interventions to address parents’ concerns and increase HPV vaccine uptake.

To examine trends in reasons for parents of unvaccinated children gave for not intending to vaccinate their adolescent children against HPV, we used data from the 2010 to 2020 National Immunization Survey-Teen (NIS-Teen). The NIS-Teen is a nationally representative random-dial-digit telephone survey of parents or guardians of adolescents aged 13 to 17 years in their household and of their primary care professionals conducted by the Centers for Disease Control and Prevention (CDC). Vaccination coverage is based on a provider-reported vaccination history; however, the provider-reported vaccination data are not verified by NIS-Teen. Details of NIS-Teen survey sampling, data collection, and weighting operations have been described previously.26  The NIS-Teen study was approved by the National Center for Health Statistics research ethics review board and is deidentified and publicly available data; therefore, ethical review and informed consent were not required for this study.

Data for the current study were limited to parents/guardians of unvaccinated adolescents (i.e., adolescents aged 13 to 17 years who had not received any HPV vaccine doses at the time of the survey) who did not intend to vaccinate their child for HPV in the next 12 months. More specifically, parents in the current study selected “not likely at all,” “not too likely,” or “not sure/do not know” in response to the question “How likely is it that [adolescent’s name] will receive HPV shots in the next 12 months?” Thus, when considering the continuum of vaccine hesitancy that ranges from complete refusal to complete acceptance of all vaccines,27  the current sample of parents can be described as “non-intenders” who are “highly hesitant” with respect to HPV vaccination.

The primary outcome was the main reason parents/guardians endorsed to indicate why they were not intending to vaccinate their adolescent child against HPV (also referred to as parental HPV vaccine hesitancy). Parents/guardians of unvaccinated adolescents who were not intending to vaccinate their child (i.e., selected “not at all likely,” “not too likely,” or “not sure/do not know” to the question about whether their child would receive HPV vaccination in the next 12 months) were further asked, “What is the main reason [your teen] will not receive HPV shots in the next 12 months?” Parents/guardians were asked to select the main reason from a total of 28 unique reasons. For the trend analyses, we limited the analysis to the top five most frequently cited reasons between the years 2010 and 2020.

Analyses were weighted to account for the complex survey design used by the NIS-Teen by using SAS survey procedures, which reduced bias owing to nonresponse and noncoverage and allowed the results to be generalized to the US adult population. Descriptive statistics were employed to describe the characteristics of the study sample (both adolescent and parent/guardian), as well as reasons for not intending to vaccinate adolescents against HPV infection. Descriptive statistics were conducted by using SAS, version 9.4 (SAS Institute Inc).

Trends in parental/guardian reasons for vaccine hesitancy were calculated by using joinpoint regression, a variant of log-linear regression.28  This method determines the number of joinpoints that are adequate for assessing significant changes in incidence trends over time. Joinpoint regression models determined the starting and ending years of increases/decreases (joinpoints) and then estimated the annual percentage change (APC) and 95% confidence intervals (CI) on the basis of a regression model between the 2 joinpoint years. The final joinpoint models were based on log-transformed percentages to better ensure the normality of residuals. The permutation test method determined the model with the fewest number of joinpoints necessary to effectively characterize trends with a maximum of 2 joinpoints. Statistical tests were 2-tailed, and P <.05 was considered statistically significant. Joinpoint regression was performed in Joinpoint 4.9.0.1 (National Cancer Institute Statistical Research Applications Branch, Bethesda, MD).

A total of 180 103 unvaccinated adolescents were included in the study, of whom 119 695 (n = 65.7%) parents/guardians were classified as “highly hesitant” with respect to HPV vaccination (i.e., their child had not received any HPV doses and they did not intend to vaccinate in the next 12 months). Adolescent and maternal characteristics are summarized in Table 1. Respondent race/ethnicity was included to describe the study sample characteristics. There was equal distribution among age groups. Most adolescents were male (60.0%), non-Hispanic white race/ethnicity (63.5%), lived above the poverty line (84.2%), and had not received a provider recommendation to get vaccinated for HPV (69.6%). Approximately 71.0% of mothers were married, and 40.4% had a college degree or higher.

TABLE 1

Characteristics of Study Sample: NIS-Teen, 2010 to 2020 (Unweighted n = 119 695)

Unweighted Frequency (Weighted %)
Adolescent  
 Age, y  
  13 24 716 (20.5) 
  14 24 575 (20.4) 
  15 23 661 (19.7) 
  16 24 106 (19.9) 
  17 22 637 (19.3) 
 Sex  
  Female 46 570 (39.0) 
  Male 73 125 (60.0) 
 Race/ethnicity  
  Non-Hispanic white 83 869 (63.5) 
  Non-Hispanic Black 10 375 (12.1) 
  Hispanic 14 404 (16.0) 
  Non-Hispanic other 11 047 (8.4) 
 Poverty status  
  Above poverty 99 339 (84.2) 
  Below poverty 12 478 (15.7) 
 Number of doctor’s visits in the past 12 mo  
  ≥4 20 612 (16.9) 
  2–3 39 268 (32.6) 
  1 36 928 (31.0) 
  None 22 125 (19.4) 
 Census region  
  Northeast 19 288 (15.4) 
  Midwest 27 012 (23.7) 
  South 45 902 (38.9) 
  West 27 493 (22.0) 
 Provider recommendation  
  Yes 36 080 (30.4) 
  No 79 234 (69.6) 
Mother  
 Age, y  
  ≤34 8053 (7.4) 
  35–44 51 517 (44.7) 
  ≥45 60 125 (47.8) 
 Marital status  
  Married 91 905 (71.0) 
  Not married 27 790 (29.0) 
 Education  
  College graduate or higher 54 912 (40.4) 
  Some college 35 962 (27.9) 
  High school graduate 20 561 (23.0) 
  Less than high school 8260 (8.7) 
 No of children aged <18 y in household  
  1 47 596 (32.8) 
  2–3 59 293 (54.2) 
  ≥4 12 806 (13.0) 
Unweighted Frequency (Weighted %)
Adolescent  
 Age, y  
  13 24 716 (20.5) 
  14 24 575 (20.4) 
  15 23 661 (19.7) 
  16 24 106 (19.9) 
  17 22 637 (19.3) 
 Sex  
  Female 46 570 (39.0) 
  Male 73 125 (60.0) 
 Race/ethnicity  
  Non-Hispanic white 83 869 (63.5) 
  Non-Hispanic Black 10 375 (12.1) 
  Hispanic 14 404 (16.0) 
  Non-Hispanic other 11 047 (8.4) 
 Poverty status  
  Above poverty 99 339 (84.2) 
  Below poverty 12 478 (15.7) 
 Number of doctor’s visits in the past 12 mo  
  ≥4 20 612 (16.9) 
  2–3 39 268 (32.6) 
  1 36 928 (31.0) 
  None 22 125 (19.4) 
 Census region  
  Northeast 19 288 (15.4) 
  Midwest 27 012 (23.7) 
  South 45 902 (38.9) 
  West 27 493 (22.0) 
 Provider recommendation  
  Yes 36 080 (30.4) 
  No 79 234 (69.6) 
Mother  
 Age, y  
  ≤34 8053 (7.4) 
  35–44 51 517 (44.7) 
  ≥45 60 125 (47.8) 
 Marital status  
  Married 91 905 (71.0) 
  Not married 27 790 (29.0) 
 Education  
  College graduate or higher 54 912 (40.4) 
  Some college 35 962 (27.9) 
  High school graduate 20 561 (23.0) 
  Less than high school 8260 (8.7) 
 No of children aged <18 y in household  
  1 47 596 (32.8) 
  2–3 59 293 (54.2) 
  ≥4 12 806 (13.0) 

Table 2 provides frequencies and proportions for all 28 reasons parents/guardians endorsed for not vaccinating their adolescents against HPV infection. The five most frequently endorsed reasons for HPV vaccine hesitancy over the entire 11-year period included “not necessary” (20.3%), “safety/side effects” (15.3%), “not recommended” (14.4%), “lack of knowledge” (12.4%), and “not sexually active” (10.3%). After the fifth most common reason, the next most frequent reason was “not appropriate age,” endorsed by 4799 parents (4.2%). The five most common reasons given by hesitant parents/guardians for not vaccinating their adolescent against HPV infection stratified by year are presented in Table 3. The results are similar to the trends from the joinpoint analyses reported below. The proportion of hesitant parents/guardians endorsing safety or side effect concerns increased over the 11-year period from 8.9% in 2010% to 25.1% in 2020. The remaining 4 reasons remained relatively stable or decreased over the 11-year period. For example, the proportion of hesitant parents/guardians endorsing “not sexually active” decreased from 14.6% in 2010% to 7.4% in 2020.

TABLE 2

Reasons Given by Parents/Guardians for Not Intending to Vaccinate Adolescent Against HPV Infection, National Immunization Survey-Teen, 2010 to 2020 (n = 119 695)

Unweighted Frequency (Weighted %)
Not necessary 22 987 (20.3) 
Safety/side effects 18 057 (15.3) 
Not recommended 15 825 (14.4) 
Lack of knowledge 13 398 (12.4) 
Not sexually active 11 803 (10.3) 
Not appropriate age 4799 (4.2) 
Parental decision 3869 (3.4) 
Child is male 3620 (3.3) 
Not required for school 2805 (2.5) 
Already up to date 2890 (2.4) 
Need more information 2445 (2.1) 
Other reason 1682 (1.5) 
Cost 1315 (1.3) 
Child fearful 1344 (1.2) 
Do not believe in vaccines 1258 (1.1) 
Child should make the decision 1155 (1.1) 
Special needs/illness 906 (0.7) 
No doctor visit scheduled 761 (0.6) 
Religion 751 (0.6) 
Increased sexual activity concern 722 (0.5) 
Effectiveness concerns 347 (0.3) 
Intend to complete but not planned 213 (0.2) 
Not available 147 (0.1) 
Time 133 (0.1) 
Transportation/appointment difficulty 117 (0.1) 
College shot 76 (0.1) 
Already sexually active 32 (0.0) 
No OB/GYN 10 (0.0) 
Unweighted Frequency (Weighted %)
Not necessary 22 987 (20.3) 
Safety/side effects 18 057 (15.3) 
Not recommended 15 825 (14.4) 
Lack of knowledge 13 398 (12.4) 
Not sexually active 11 803 (10.3) 
Not appropriate age 4799 (4.2) 
Parental decision 3869 (3.4) 
Child is male 3620 (3.3) 
Not required for school 2805 (2.5) 
Already up to date 2890 (2.4) 
Need more information 2445 (2.1) 
Other reason 1682 (1.5) 
Cost 1315 (1.3) 
Child fearful 1344 (1.2) 
Do not believe in vaccines 1258 (1.1) 
Child should make the decision 1155 (1.1) 
Special needs/illness 906 (0.7) 
No doctor visit scheduled 761 (0.6) 
Religion 751 (0.6) 
Increased sexual activity concern 722 (0.5) 
Effectiveness concerns 347 (0.3) 
Intend to complete but not planned 213 (0.2) 
Not available 147 (0.1) 
Time 133 (0.1) 
Transportation/appointment difficulty 117 (0.1) 
College shot 76 (0.1) 
Already sexually active 32 (0.0) 
No OB/GYN 10 (0.0) 
TABLE 3

Most Commonly Reasons Given by Parents/Guardians for Not Intending to Vaccinate Adolescent Against HPV Infection Stratified by Year, National Immunization Survey-Teen, 2010 to 2020 (n = 119 695)

YearNot NecessaryNot RecommendedSafety/Side Effect ConcernsLack of KnowledgeNot Sexually ActiveAll Other Reasons Combined
2010 3525 (20.9) 2427 (15.1) 1482 (8.9) 2184 (13.6) 2549 (14.6) 4618 (27.0) 
2011 2093 (22.5) 1301 (14.3) 784 (8.8) 1008 (11.7) 1391 (14.9) 2525 (27.3) 
2012 2598 (21.8) 2234 (19.1) 1114 (9.1) 1860 (15.9) 1182 (10.1) 2775 (24.1) 
2013 2045 (19.2) 1935 (19.1) 1071 (11.0) 1501 (15.9) 1018 (9.3) 2744 (25.6) 
2014 2474 (22.3) 1453 (13.0) 1387 (12.7) 1436 (13.9) 1134 (10.5) 3054 (27.6) 
2015 2608 (24.0) 1522 (13.6) 1542 (13.0) 1477 (13.2) 1233 (11.1) 2883 (25.1) 
2016 2307 (22.7) 1229 (12.6) 2065 (19.3) 1172 (12.2) 976 (9.1) 2470 (24.1) 
2017 1518 (15.3) 1131 (12.8) 2169 (22.1) 942 (10.6) 757 (7.4) 3094 (31.8) 
2018 1289 (17.0) 968 (11.5) 2013 (23.4) 745 (8.3) 665 (7.8) 2576 (32.0) 
2019 1201 (15.6) 945 (11.7) 1973 (26.2) 685 (8.9) 597 (6.8) 2352 (30.8) 
2020 1170 (15.6) 839 (11.4) 1882 (25.1) 606 (8.1) 557 (7.4) 2407 (32.5) 
YearNot NecessaryNot RecommendedSafety/Side Effect ConcernsLack of KnowledgeNot Sexually ActiveAll Other Reasons Combined
2010 3525 (20.9) 2427 (15.1) 1482 (8.9) 2184 (13.6) 2549 (14.6) 4618 (27.0) 
2011 2093 (22.5) 1301 (14.3) 784 (8.8) 1008 (11.7) 1391 (14.9) 2525 (27.3) 
2012 2598 (21.8) 2234 (19.1) 1114 (9.1) 1860 (15.9) 1182 (10.1) 2775 (24.1) 
2013 2045 (19.2) 1935 (19.1) 1071 (11.0) 1501 (15.9) 1018 (9.3) 2744 (25.6) 
2014 2474 (22.3) 1453 (13.0) 1387 (12.7) 1436 (13.9) 1134 (10.5) 3054 (27.6) 
2015 2608 (24.0) 1522 (13.6) 1542 (13.0) 1477 (13.2) 1233 (11.1) 2883 (25.1) 
2016 2307 (22.7) 1229 (12.6) 2065 (19.3) 1172 (12.2) 976 (9.1) 2470 (24.1) 
2017 1518 (15.3) 1131 (12.8) 2169 (22.1) 942 (10.6) 757 (7.4) 3094 (31.8) 
2018 1289 (17.0) 968 (11.5) 2013 (23.4) 745 (8.3) 665 (7.8) 2576 (32.0) 
2019 1201 (15.6) 945 (11.7) 1973 (26.2) 685 (8.9) 597 (6.8) 2352 (30.8) 
2020 1170 (15.6) 839 (11.4) 1882 (25.1) 606 (8.1) 557 (7.4) 2407 (32.5) 

Figures 1A and 1B show the trends in parental/guardian HPV vaccine hesitancy and reasons for HPV vaccine hesitancy, respectively, and Table 4 details the corresponding APC. Overall, parental/guardian HPV vaccine hesitancy decreased by 5.5% annually between 2010 and 2012 (APC, −5.5; 95% CI, −8.5 to −2.3; P = .006) and then remained stable for the 9-year period of 2012 through 2020 (Fig 1A and Table 4). The proportion of parents/guardians citing “safety or side effects” as the main reason for vaccine hesitancy increased significantly by 15.6% annually from 2010 to 2018 (APC, 15.6; 95% CI, 10.5% to 20.8%; P ≤.001) and has remained stable from 2018 to 2020. The proportion of parents/guardians citing “not recommended” as the main reason for vaccine hesitancy remained stable from 2010 to 2013 but decreased by 6.8% per year between 2013 and 2020 (APC, −6.8%; 95% CI, −11.0% to −2.4%; P = .010). Similarly, parents/guardians citing “lack of knowledge” as the main reason for vaccine hesitancy remained stable from 2010 to 2013 but then decreased by 9.9% annually from 2013 to 2020 (APC, −9.9%; 95% CI, −14.4% to −5.1%; P = .003). Finally, parents/guardians citing “child not sexually active” as the main reason for vaccine hesitancy remained stable from 2010 to 2012 and then decreased by 5.9% per year from 2012 to 2020 (APC, −5.9%; 95% CI, −10.4% to −1.2%; P = .022). No significant changes were observed for parents citing “not necessary” over the reporting period.

FIGURE 1

APC in HPV vaccine hesitancy and reasons given by parents/guardians for not intending to vaccinate adolescent against HPV infection from 2010 to 2020: (A) overall HPV vaccine hesitancy (B) reasons given for HPV vaccine hesitancy.

Data: NIS-Teen

FIGURE 1

APC in HPV vaccine hesitancy and reasons given by parents/guardians for not intending to vaccinate adolescent against HPV infection from 2010 to 2020: (A) overall HPV vaccine hesitancy (B) reasons given for HPV vaccine hesitancy.

Data: NIS-Teen

Close modal
TABLE 4

Annual Percentage Change Over Time in the Parent/Guardian Reasons for Human Papillomavirus Vaccine Hesitancy From 2010 to 2020 (National Immunization Survey-Teen)

BarriersAPCLower CIUpper CIP
Overall     
 2010–2012 −5.5 −8.5 −2.3 .006 
 2012–2020 −0.2 −0.7 0.3 .322 
Safety or side effects     
 2010–2018 15.6 10.5 20.8 <.001 
 2018–2020 3.5 −28.3 49.4 .825 
Not necessary     
 2010–2015 1.5 −5.5 9.0 .628 
 2015–2020 −8.6 −16.9 0.5 .059 
Not recommended     
 2010–2013 11.4 −22.0 59.1 .488 
 2013–2020 −6.8 −11.0 −2.4 .010 
Lack of knowledge     
 2010–2013 6.9 −5.7 21.1 .240 
 2013–2020 −9.9 −14.4 −5.1 .003 
Child not sexually active     
 2010–2012 −13.6 −34.0 13.1 .232 
 2012–2020 −5.9 −10.4 −1.2 .022 
BarriersAPCLower CIUpper CIP
Overall     
 2010–2012 −5.5 −8.5 −2.3 .006 
 2012–2020 −0.2 −0.7 0.3 .322 
Safety or side effects     
 2010–2018 15.6 10.5 20.8 <.001 
 2018–2020 3.5 −28.3 49.4 .825 
Not necessary     
 2010–2015 1.5 −5.5 9.0 .628 
 2015–2020 −8.6 −16.9 0.5 .059 
Not recommended     
 2010–2013 11.4 −22.0 59.1 .488 
 2013–2020 −6.8 −11.0 −2.4 .010 
Lack of knowledge     
 2010–2013 6.9 −5.7 21.1 .240 
 2013–2020 −9.9 −14.4 −5.1 .003 
Child not sexually active     
 2010–2012 −13.6 −34.0 13.1 .232 
 2012–2020 −5.9 −10.4 −1.2 .022 

Although HPV vaccination rates in the United States have steadily improved over the past decade, a sizeable subset of parents remains highly hesitant about administering the vaccine to their adolescent children. In this study, we examined trends in the top five reasons for HPV vaccine hesitancy from 2010 to 2020 among US parents/guardians who had not vaccinated their adolescents for HPV and had no intention to vaccinate them in the next 12 months. During the 11-year period, the most common reasons parents endorsed were “not needed or not necessary,” “safety/side effects concerns,” “not recommended,” “lack of knowledge,” and “child not sexually active.” We also observed important trends in these reasons over time, namely an increase in the percentage of parents/guardians citing safety concerns and a decrease in nearly all other reasons.

Decreases in the percentage of parents/guardians citing lack of provider recommendation, lack of knowledge, and child “not sexually active” as the main reason for HPV vaccine hesitancy during the 11-year period are encouraging and suggest that interventions have been successful in reducing perceived barriers to HPV vaccination. Indeed, these findings are consistent with previous research, including studies that have examined data from NIS-Teen, which revealed similar declines.2022,29,30  To increase the uptake of HPV vaccination, the National Vaccination Advisory Committee has proposed several recommendations that are focused on improving provider recommendation and reducing missed clinical opportunities for vaccination, as well as increasing parental demand for the vaccine.31  Provider recommendation has been shown to be the single best predictor of HPV vaccine uptake and vaccine acceptability.3234  One explanation for the decrease in parents citing these 3 reasons for hesitancy is that provider recommendation for HPV vaccination has increased. For instance, Sonawane et al found that provider recommendation for the HPV vaccine increased from 27.0% in 2012% to 49.3% in 2018.35  Second, the decrease could be attributed to improved educational outreach and evidence that the vaccine is not associated with increased sexual behavior,36,37  as well as interventions addressing lack of knowledge.25  Despite the decrease in these 3 reasons, a substantial group of parents/guardians remain unwilling to vaccinate their children for HPV, which may indicate that provider recommendation or improved knowledge about the vaccine alone may be ineffective in motivating these hesitant parents/guardians to vaccinate.

Over the 11-year period, we also found a significant increase in the proportion of parents/guardians citing safety/side effect concerns as the main reason for HPV vaccine hesitancy. This increasing trend in safety concerns is consistent with previous research.22,29,30  Our study advances the literature by examining the primary reasons for HPV vaccine hesitancy over a decade-long period and by using data through 2020 versus 2016.22  The observed increase in safety concerns may be due to several reasons. One likely possibility could be related to the widespread distribution of vaccine misinformation on the internet. According to the Pew Research Center, internet use in the United States has increased from 76% in 2010 to 93% in 2021,38  and social media accounts run by antivaccination proponents have increased by 7.8 million since 2019.39  Fear tactics are often used by antivaccine campaigners to dissuade parents from vaccinating their children. There have been several myths propagated about vaccines causing adverse reactions, including diseases like autism, multiple sclerosis, autoimmune diseases, ovarian failure, and even death. Although these myths have been scientifically debunked, they continue to circulate.40,41  Doubts about HPV vaccine safety are exacerbated by misinformation spread through social media and other platforms.42  It has been documented that exposure to or engagement with negative HPV vaccine content is associated with HPV vaccine hesitancy.42,43  Unfortunately, there has been an increase in such content on social media and other platforms over the years, which may, in part, explain the rise in safety concerns we observed.44,45  It should be noted that these data were collected before the coronavirus disease 2019 pandemic and, therefore, it is reasonable to expect that HPV vaccine-related safety concerns may continue to rise because of the plethora of misinformation surrounding coronavirus disease 2019 vaccination.46 

Although parental concerns about the safety of the vaccine have been on the rise, there is no scientific basis underlying the belief that the HPV vaccine is unsafe. In fact, a recent study by Sonawane et al revealed a decreasing trend in nonserious adverse effects (AE) and no change in serious AE reporting trends from 2015 to 2018.30  They reported that, of the 16 621 AEs reported to the Vaccine Adverse Event Reporting System after HPV vaccination, 95.4% were nonserious AEs.30  In addition, the CDC monitors the safety of vaccines and reports that, of the ∼108 million HPV doses administered between June 2006 and December 2017, there has been no association between vaccination and death.47  Moreover, neither the Food and Drug Administration nor the CDC has found any association between HPV vaccination and reproductive issues such as primary ovarian insufficiency or early menopause.47 

Despite several strengths of our study, including using a nationally representative data source, a large sample size, and more than a decade of data to evaluate trends over time, our study is not without limitations. First, reasons underlying HPV vaccine hesitancy may be broader than those represented in this study because NIS-Teen does not ask parents of vaccinated children about hesitancy; thus, parents who overcame their hesitancy to vaccinate their child are not clearly delineated here. Accordingly, the reasons given by the current subset of parents may not be representative of the reasons parents/guardians are hesitant overall. Second, there is a possibility of recall bias on children’s HPV vaccination status, however, the use of provider-verified records should help reduce the bias. The third is nonresponse bias (sampling bias), although the use of weighting potentially reduces this bias. It is possible that vaccine-hesitant parents/guardians who are leery of research and the medical establishment may have refused to respond to the NIS-Teen survey. Thus, these subgroups may not be represented in the current findings. Finally, vaccine decision-making is complex, and the reasons for the lack of intent to vaccinate are likely multifactorial. We were able to report only the primary reason from each parent, whereas interventions may need to address multiple reasons concurrently.

We demonstrated that parents’ reasons for not intending to vaccinate their adolescent son or daughter against HPV infection have changed over time. Although reasons relating to lack of provider recommendation, lack of knowledge, and their child not being sexually active decreased in importance from 2013 to 2020, concerns regarding HPV vaccine safety have increased despite consistent evidence of the vaccine’s favorable safety profile. HPV vaccine uptake has improved over time with >70% of US adolescents estimated to have initiated the series as of 2020. Closing the gap on the remaining 28% will likely require a mix of current and newer approaches to address vaccine hesitancy. Our findings suggest that strategies to combat safety concerns and improve vaccine confidence are urgently warranted. These findings support local, state, and national efforts to inform parents of the benefits of HPV vaccination for cancer prevention and to develop and disseminate strategies for addressing parental concerns about HPV vaccination. It may also be beneficial to tailor interventions to parents’ level of hesitancy and the main reason they are hesitant to vaccinate their children.21  Future studies are needed to identify and implement tailored interventions that address common reasons for parental HPV vaccine hesitancy, particularly increasing safety concerns.

Dr Adjei Boakye conceptualized and designed the study, obtained data, conducted the analyses, drafted the initial manuscript, and critically reviewed and revised the manuscript for important intellectual content; Drs Nair and Abouelella obtained data, conducted the analyses, and drafted the initial manuscript; Drs Joseph, Gerend, and Subramaniam critically reviewed and revised the manuscript for important intellectual content; Dr Osazuwa-Peters conceptualized and designed the study, and critically reviewed and revised the manuscript for important intellectual content; and all authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.

FUNDING: Dr Osazuwa-Peters reported receiving grants from the National Institute of Health/National Institute of Dental and Craniofacial Research (K01DE030916) outside of the submitted work.

CONFLICTS OF INTEREST: Dr Osazuwa-Peters is a scientific advisor to Navigating Cancer. The other coauthors had no conflict to declare.

AE

adverse effects

APC

annual percentage change

CDC

Centers for Disease Control and Prevention

CI

confidence interval

HPV

human papillomavirus

NIS-Teen

National Immunization Survey-Teen

1
Gillison
ML
,
Chaturvedi
AK
,
Lowy
DR
.
HPV prophylactic vaccines and the potential prevention of noncervical cancers in both men and women
.
Cancer
.
2008
;
113
(
10 Suppl
):
3036
3046
2
Chesson
HW
,
Dunne
EF
,
Hariri
S
, %
Markowitz
LE
.
The estimated lifetime probability of acquiring human papillomavirus in the United States
.
Sex Transm Dis
.
2014
;
41
(
11
):
660
664
3
Centers for Disease Control and Prevention
.
HPV-associated cancer statistics
.
Available at: https://www.cdc.gov/cancer/hpv/statistics/cases.htm. Accessed March 14, 2021
4
Adjei Boakye
E
,
Buchanan
P
,
Hinyard
L
, et al
.
Incidence and risk of second primary malignant neoplasm after a first head and neck squamous cell carcinoma
.
JAMA Otolaryngol Head Neck Surg
.
2018
;
144
(
8
):
727
737
5
Suk
R
,
Mahale
P
,
Sonawane
K
, et al
.
Trends in risks for second primary cancers associated with index human papillomavirus-associated cancers
.
JAMA Netw Open
.
2018
;
1
(
5
):
e181999
e181999
6
Wang
M
,
Sharma
A
,
Osazuwa-Peters
N
, et al
.
Risk of subsequent malignant neoplasms after an index potentially- human papillomavirus (HPV)-associated cancers
.
Cancer Epidemiol
.
2020
;
64
:
101649
7
Adjei Boakye
E
,
Grubb
L
,
Peterson
CE
, et al
.
Risk of second primary cancers among survivors of gynecological cancers
.
Gynecol Oncol
.
2020
;
158
(
3
):
719
726
8
Centers for Disease Control and Prevention
.
Cancers associated with human papillomavirus, United States—2012–2016
.
9
Osazuwa-Peters
N
,
Simpson
MC
,
Massa
ST
, et al
.
40-year incidence trends for oropharyngeal squamous cell carcinoma in the United States
.
Oral Oncol
.
2017
;
74
:
90
97
10
Deshmukh
AA
,
Suk
R
,
Shiels
MS
, et al
.
Recent trends in squamous cell carcinoma of the anus incidence and mortality in the United States, 2001-2015
.
J Natl Cancer Inst
.
2020
;
112
(
8
):
829
838
11
Meites
E
,
Szilagyi
PG
,
Chesson
HW
, et al
.
Human papillomavirus vaccination for adults: updated recommendations of the advisory committee on immunization practices
.
MMWR Morb Mortal Wkly Rep
.
2019
;
68
(
32
):
698
702
12
Petrosky
EY
,
Liu
G
,
Hariri
S
,
Markowitz
LE
.
Human papillomavirus vaccination and age at first sexual activity, National Health and Nutrition Examination Survey
.
Clin Pediatr (Phila)
.
2017
;
56
(
4
):
363
370
13
14
Pingali
C
,
Yankey
D
,
Elam-Evans
LD
, et al
.
National, regional, state, and selected local area vaccination coverage among adolescents aged 13–17 years - United States, 2020
.
MMWR Morb Mortal Wkly Rep
.
2021
;
70
(
35
):
1183
1190
15
Szilagyi
PG
,
Albertin
CS
,
Gurfinkel
D
, et al
.
Prevalence and characteristics of HPV vaccine hesitancy among parents of adolescents across the US
.
Vaccine
.
2020
;
38
(
38
):
6027
6037
16
Hickler
B
,
Guirguis
S
,
Obregon
R
.
Vaccine special issue on vaccine hesitancy
.
Vaccine
.
2015
;
33
(
34
):
4155
4156
17
Sonawane
K
,
Zhu
Y
,
Montealegre
JR
, et al
.
Parental intent to initiate and complete the human papillomavirus vaccine series in the USA: a nationwide, cross-sectional survey
.
Lancet Public Health
.
2020
;
5
(
9
):
e484
e492
18
Holman
DM
,
Benard
V
,
Roland
KB
, et al
.
Barriers to human papillomavirus vaccination among US adolescents: a systematic review of the literature
.
JAMA Pediatr
.
2014
;
168
(
1
):
76
82
19
Gilkey
MB
,
Calo
WA
,
Marciniak
MW
,
Brewer
NT
.
Parents who refuse or delay HPV vaccine: differences in vaccination behavior, beliefs, and clinical communication preferences
.
Hum Vaccin Immunother
.
2017
;
13
(
3
):
680
686
20
Thompson
EL
,
Rosen
BL
,
Vamos
CA
, et al
.
Human papillomavirus vaccination: what are the reasons for nonvaccination among U.S. adolescents?
J Adolesc Health
.
2017
;
61
(
3
):
288
293
21
Rositch
AF
,
Liu
T
,
Chao
C
, et al
.
Levels of parental human papillomavirus vaccine hesitancy and their reasons for not intending to vaccinate: insights from the 2019 National Immunization Survey-Teen
.
J Adolesc Health
.
2022
;
71
(
1
):
39
46
22
Hirth
JM
,
Fuchs
EL
,
Chang
M
, et al
.
Variations in reason for intention not to vaccinate across time, region, and by race/ethnicity, NIS-Teen (2008–2016)
.
Vaccine
.
2019
;
37
(
4
):
595
601
23
Mavundza
EJ
,
Iwu-Jaja
CJ
,
Wiyeh
AB
, et al
.
A systematic review of interventions to improve HPV vaccination coverage
.
Vaccines (Basel)
.
2021
;
9
(
7
):
687
24
Constable
C
,
Ferguson
K
,
Nicholson
J
,
Quinn
GP
.
Clinician communication strategies associated with increased uptake of the human papillomavirus (HPV) vaccine: a systematic review
.
CA Cancer J Clin
.
2022
;
72
(
6
):
561
569
25
Smulian
EA
,
Mitchell
KR
,
Stokley
S
.
Interventions to increase HPV vaccination coverage: a systematic review
.
Hum Vaccin Immunother
.
2016
;
12
(
6
):
1566
1588
26
Center for Disease Control and Prevention
.
National immunization surveys (NIS)
.
Available at: https://www.cdc.gov/vaccines/imz-managers/nis/about.html. Accessed July 28, 2022
27
Dubé
E
,
Laberge
C
,
Guay
M
, et al
.
Vaccine hesitancy: an overview
.
Hum Vaccin Immunother
.
2013
;
9
(
8
):
1763
1773
28
Kim
HJ
,
Fay
MP
,
Feuer
EJ
,
Midthune
DN
.
Permutation tests for joinpoint regression with applications to cancer rates
.
Stat Med
.
2000
;
19
(
3
):
335
351
29
Beavis
A
,
Krakow
M
,
Levinson
K
,
Rositch
AF
.
Reasons for lack of HPV vaccine initiation in NIS-Teen over time: shifting the focus from gender and sexuality to necessity and safety
.
J Adolesc Health
.
2018
;
63
(
5
):
652
656
30
Sonawane
K
,
Lin
YY
,
Damgacioglu
H
, et al
.
Trends in human papillomavirus vaccine safety concerns and adverse event reporting in the United States
.
JAMA Netw Open
.
2021
;
4
(
9
):
e2124502
31
National Vaccine Advisory Committee
.
Overcoming barriers to low HPV vaccine uptake in the United States: recommendations from the National Vaccine Advisory Committee: approved by the National Vaccine Advisory Committee on June 9, 2015
.
Public Health Rep
.
2016
;
131
(
1
):
17
25
32
Mohammed
KA
,
Geneus
CJ
,
Osazuwa- Peters
N
, et al
.
Disparities in provider recommendation of human papillomavirus vaccination for U.S. adolescents
.
J Adolesc Health
.
2016
;
59
(
5
):
592
598
33
Newman
PA
,
Logie
CH
,
Lacombe-Duncan
A
, et al
.
Parents’ uptake of human papillomavirus vaccines for their children: a systematic review and meta-analysis of observational studies
.
BMJ Open
.
2018
;
8
(
4
):
e019206
34
Gargano
LM
,
Herbert
NL
,
Painter
JE
, et al
.
Impact of a physician recommendation and parental immunization attitudes on receipt or intention to receive adolescent vaccines
.
Hum Vaccin Immunother
.
2013
;
9
(
12
):
2627
2633
35
Sonawane
K
,
Zhu
Y
,
Lin
YY
, et al
.
HPV vaccine recommendations and parental intent
.
Pediatrics
.
2021
;
147
(
3
):
e2020026286
36
Rysavy
MB
,
Kresowik
JD
,
Liu
D
, et al
.
Human papillomavirus vaccination and sexual behavior in young women
.
J Pediatr Adolesc Gynecol
.
2014
;
27
(
2
):
67
71
37
Mullins
TL
,
Widdice
LE
,
Rosenthal
SL
, et al
.
Risk perceptions, sexual attitudes, and sexual behavior after HPV vaccination in 11–12-year-old girls
.
Vaccine
.
2015
;
33
(
32
):
3907
3912
38
Pew Research Center
.
Internet/ broadband fact sheet
.
39
Burki
T
.
The online anti-vaccine movement in the age of COVID-19
.
Lancet Digit Health
.
2020
;
2
(
10
):
e504
e505
40
Patel
PR
,
Berenson
AB
.
Sources of HPV vaccine hesitancy in parents
.
Hum Vaccin Immunother
.
2013
;
9
(
12
):
2649
2653
41
Bednarczyk
RA
.
Addressing HPV vaccine myths: practical information for healthcare providers
.
Hum Vaccin Immunother
.
2019
;
15
(
7–8
):
1628
1638
42
Margolis
MA
,
Brewer
NT
,
Shah
PD
, et al
.
Stories about HPV vaccine in social media, traditional media, and conversations
.
Prev Med
.
2019
;
118
:
251
256
43
Argyris
YA
,
Kim
Y
,
Roscizewski
A
,
Song
W
.
The mediating role of vaccine hesitancy between maternal engagement with anti- and pro-vaccine social media posts and adolescent HPV-vaccine uptake rates in the US: the perspective of loss aversion in emotion-laden decision circumstances
.
Soc Sci Med
.
2021
;
282
:
114043
44
Luo
X
,
Zimet
G
,
Shah
S
.
A natural language processing framework to analyse the opinions on HPV vaccination reflected in twitter over 10 years (2008−2017)
.
Hum Vaccin Immunother
.
2019
;
15
(
7-8
):
1496
1504
45
Chin
J
,
Chin
C-L
,
Panday
S
, et al
.
Tracking the human papillomavirus vaccine risk misinformation: an explorative study to examine how the misinformation has spread in user-generated content
.
Proceedings of the International Symposium on Human Factors and Ergonomics in Health Care
.
2020
;
9
(
1
):
312
316
46
Manganello
JA
,
Chiang
SC
,
Cowlin
H
, et al
.
HPV and COVID-19 vaccines: social media use, confidence, and intentions among parents living in different community types in the United States [published online ahead of print June 7, 2022]
.
J Behav Med
.
doi:10.1007/s10865-022-00316-3
47
Center for Disease Control and Prevention
.
Questions about HPV vaccine safety
.