The association of initiating HPV vaccination at ages 9-10 years and up-to-date status among adolescents ages 13-17 years, 2016-2020

Recent guidelines from the American Cancer Society stress HPV vaccination series initiation at the youngest opportunity, i.e., age 9 years. There are limited data on the association between initiating HPV vaccination at ages 9-10 years and up-to-date (UTD) status. In this study, we compare nationally representative UTD HPV vaccination rates between adolescents who initiated the series younger (ages 9-10 years) vs. older (≥ age 11 years). Five years of pooled data (2016-2020) from National Immunization Survey-Teen were used to estimate the UTD HPV vaccination prevalence among younger vs. older initiating 13-17-year-olds. Adjusted logistic regression models estimated prevalence ratios (aPRs), differences (aDs), and difference in differences (aDDs) in prevalence of being UTD to assess the overall association of age at initiation with being UTD and differences in sociodemographic predictors of being UTD among younger vs. older initiators. UTD prevalence for younger initiators was 93% compared with 72% among older initiators (aPR: 1.27,95%CI: 1.24,1.31). Among older initiators, UTD prevalence was significantly different by sex, insurance status, and current age; no such differences were observed among younger initiators. Results indicate that younger initiation is associated with a 27% higher UTD prevalence, highlighting the importance of promoting younger initiation, particularly among those with health-care barriers.

Trends in Adolescent Human Papillomavirus Vaccination and Parental Hesitancy in the United States

BACKGROUND

Human papillomavirus (HPV) vaccination coverage remains suboptimal in the United States, underscoring the importance of monitoring trends in vaccine hesitancy.

METHODS

Cross-sectional data from the 2011-2020 National Immunization Survey-Teen were used to assess trends in HPV vaccination initiation among 13-17-year-olds, parental intent to initiate vaccination, and primary reasons for parental hesitancy.

RESULTS

Among all sex and race and ethnicity groups, the prevalence of HPV vaccination initiation increased over time, but parental intent to vaccinate against HPV for unvaccinated teens remained consistently low (≤45%). Among hesitant parents, "safety concerns" increased in nearly all demographic groups, with the greatest increases observed for non-Hispanic white female and male teens and no change for non-Hispanic black female teens. In 2019-2020, parents of unvaccinated non-Hispanic white teens were least likely to intend on vaccinating their teens, and the most common reason for hesitancy varied by sex and race and ethnicity (eg, "safety concerns" for white teens and "not necessary" for black female teens).

CONCLUSIONS

Although HPV vaccination initiation increased over time, a substantial fraction of parents remain hesitant, and trends in their reason varied by sex and race and ethnicity. Health campaigns and clinicians should address vaccine safety and necessity.

Human papillomavirus vaccine uptake among teens before and during the COVID-19 pandemic in the United States

It is unclear how the COVID-19 pandemic impacted human papillomavirus (HPV) vaccine uptake and which sociodemographic groups may have been most impacted. We aimed to assess differences in HPV vaccine uptake (initiation and completion) before and during the pandemic in the United States. We conducted a cross-sectional study using data from the 2019 to 2020 National Immunization Surveys - Teen (NIS-Teen), comparing vaccine initiation and completion rates in 2019 vs. 2020, based on confirmed reports by a healthcare provider. Weighted logistic regression analysis estimated odds of vaccine initiation and completion for both adolescent and parental characteristics. There were 18,788 adolescents in 2019 and 20,162 in 2020. There was 3.6% increase in HPV vaccine initiation (71.5% vs. 75.1%) and a 4.4% in completion (54.2% vs. 58.6%) rates from 2019 to 2020. In 2020, Non-Hispanic White teens were significantly less likely to initiate (aOR = 0.62, 95% CI: 0.49, 0.79) and complete (aOR = 0.71, 95% CI: 0.58, 0.86) vaccine uptake compared with non-Hispanic Black teens. Additionally, teens who lived above the poverty line were also less likely to initiate HPV vaccination (aOR = 0.63, 95% CI: 0.49, 0.80) or complete them (aOR = 0.73, 95% CI: 0.60, 0.90), compared to those who lived below the poverty line. During the COVID-19 pandemic in 2020, some historically advantaged socioeconomic groups such as those living above the poverty line were less likely to receive HPV vaccine. The impact of the pandemic on HPV vaccine uptake may transcend traditional access to care factors.

Estimating the number of US children susceptible to measles resulting from COVID-19-related vaccination coverage declines

Measles elimination hinges on vaccination coverage remaining above 95% to retain sufficient community protection. Recent declines in routine measles vaccinations due to the COVID-19 pandemic coupled with prior models indicating the country was close to the 92% herd immunity benchmark are a cause for concern. We evaluated population-level measles susceptibility in the US, including sensitivity analyses accounting for pandemic-related impacts on immunization. We estimated the number of children aged 0–18 currently susceptible to measles and modeled susceptibility proportions in decreased vaccination scenarios. Participants were respondents to the NIS-Teen survey between 2008 and 2017 that also had provider-verified vaccination documentation. The exposure of interest was vaccination with a measles-containing vaccine (MCV), and the age at which they were vaccinated for all doses given. Using age at vaccination, we estimated age-based probabilities of vaccination and modeled population levels of MCV immunization and immunity vs. susceptibility. Currently, 9,145,026 children (13.1%) are estimated to be susceptible to measles. With pandemic level vaccination rates, 15,165,221 children (21.7%) will be susceptible to measles if no attempt at catch-up is made, or 9,454,436 children (13.5%) if catch-up vaccinations mitigate the decline by 2–3%. Models based on increased vaccine hesitancy also show increased susceptibility at national levels, with a 10% increase in hesitancy nationally resulting in 14,925,481 children (21.37%) susceptible to measles, irrespective of pandemic vaccination levels. Current levels of measles immunity remain below herd immunity thresholds. If pandemic-era reductions in childhood immunization are not rectified, population-level immunity to measles is likely to decline further.

Factors Associated With Receipt of Meningococcal B Vaccine Among United States Adolescents, National Immunization Survey-Teen, 2017-2018

PURPOSE

In this study, we evaluated factors associated with receipt of meningococcal serogroup B (MenB) vaccine among adolescents in the United States.

METHODS

We used public use data files from the National Immunization Survey-Teen from 2017 to 2018. Logistic regression was used to model associations among sociodemographic, healthcare, and vaccination variables of interest and MenB vaccine receipt (≥1 vs. 0 dose). To explore associations between state-level meningococcal vaccination requirements and MenB vaccine uptake, we performed a secondary analysis stratified by presence of a quadrivalent meningococcal (MenACWY) vaccination requirement for secondary school attendance in the adolescent's state of residence (no requirement vs. a one- or two-dose requirement).

RESULTS

Among 7,288 adolescents, MenB vaccine receipt was significantly associated with up-to-date human papillomavirus (adjusted odds ratio [aOR] 1.74, 95% confidence interval [CI] 1.29-2.35) and MenACWY (aOR 5.81, 95% CI 4.14-8.13) vaccination status in multivariable analysis. Adolescents with private insurance were less likely to be vaccinated (aOR .61, 95% CI .46-.79) compared to adolescents with other health insurance types. In secondary analyses, health insurance was no longer significantly associated with MenB vaccine uptake among adolescents in states with a MenACWY requirement.

CONCLUSIONS

We found that MenB vaccination is associated with receipt of other vaccines recommended for use in adolescents. Adolescents with private health insurance were less likely to be vaccinated against MenB, although state MenACWY requirements appeared to modify the effect of insurance on MenB vaccine receipt. Further work to understand how these factors may influence delivery and acceptance of MenB vaccine can inform interventions and strategies to improve uptake.

A Mixed-Methods Analysis of Barriers to and Facilitators of Human Papillomavirus Vaccination Among Adolescents in Montana

OBJECTIVES

Human papillomavirus (HPV) vaccination rates among adolescents are lower in rural areas than in urban areas of the United States. The objective of this study was to identify barriers to and facilitators of adolescent HPV vaccination in Montana, a large, primarily rural state.

METHODS

Using a mixed-methods design, we integrated quantitative analyses of Montana's National Immunization Survey-Teen (NIS-Teen) data from 2013-2017 with qualitative data collected at a statewide meeting in October 2018 and from stakeholder interviews conducted from October 2018 through June 2019. Using NIS-Teen data, we identified trends and estimated adjusted prevalence ratios (aPRs) to identify factors associated with vaccine uptake. Using directed content analysis of qualitative data, we identified themes related to vaccine uptake.

RESULTS

In Montana, initiation of the HPV vaccine series among adolescents aged 13-17 increased from 34.4% in 2013 to 65.5% in 2017. We identified 6 themes related to HPV vaccination from qualitative analyses, including medical providers' recommendation style as a facilitator of vaccination and parental vaccine hesitancy as a barrier to vaccination. In NIS-Teen 2017 data (n = 326 adolescents), receiving a medical provider recommendation was significantly associated with series initiation (aPR = 2.3; 95% CI, 1.5-3.6). Among parents who did not intend to initiate the vaccine series for their adolescent within 12 months (n = 71), vaccine safety was the top concern (aPR = 24.5%; 95% CI, 12.1%-36.9%).

CONCLUSIONS

HPV vaccination rates have increased in Montana but remain lower than rates for other adolescent vaccines. Future work should focus on reducing missed opportunities, increasing parents' knowledge of and confidence in vaccination, and training medical providers on addressing common vaccine concerns.

Racial/Ethnic Disparities in Influenza Vaccination Coverage Among US Adolescents, 2010-2016

OBJECTIVE

Although research suggests racial/ethnic disparities in influenza vaccination and mortality rates, few studies have examined racial/ethnic trends among US adolescents. We used national cross-sectional data to determine (1) trends in influenza vaccination rates among non-Hispanic white (hereinafter, white), non-Hispanic black (hereinafter, black), and Hispanic adolescents over time and (2) whether influenza vaccination rates among adolescents varied by race/ethnicity.

METHODS

We analyzed provider-reported vaccination histories for 2010-2016 from the National Immunization Survey-Teen. We used binary logistic regression models to determine trends in influenza vaccination rates by race/ethnicity for 117 273 adolescents, adjusted for sex, age, health insurance, physician visit in the previous 12 months, vaccination facility type, poverty status, maternal education level, children in the household, maternal marital status, maternal age, and census region of residence. We calculated adjusted probabilities for influenza vaccination for each racial/ethnic group, adjusted for the same demographic characteristics.

RESULTS

Compared with white adolescents, Hispanic adolescents had higher odds (adjusted odds ratio [aOR] = 1.11; 95% confidence interval [CI], 1.06-1.16) and black adolescents had lower odds (aOR = 0.95; 95% CI, 0.90-1.00) of vaccination. Compared with white adolescents, Hispanic adolescents had significantly higher adjusted probabilities of vaccination for 2011-2013 (2011: 0.22, P < .001; 2012: 0.23, P < .001; 2013: 0.26, P < .001). Compared with white adolescents, black adolescents had significantly lower probabilities of vaccination for 2016 (2016: 0.21, P < .001).

CONCLUSIONS

Targeted interventions are needed to improve adolescent influenza vaccination rates and reduce racial/ethnic disparities in adolescent vaccination coverage.

Reasons for Lack of HPV Vaccine Initiation in NIS-Teen Over Time: Shifting the Focus From Gender and Sexuality to Necessity and Safety

PURPOSE

To describe changes in parents' reasons for lack of HPV vaccine initiation in American male and female adolescents from 2010 to 2016.

METHODS

Log binomial regression was used to examine prevalence and trends across time in reasons parents do not intend to vaccinate from the National Immunization Survey - Teen (NIS-Teen).

RESULTS

In females, safety concerns were the most common reasons in 2010 (23%) and 2016 (22%). Lack of necessity (21% vs. 20%), knowledge (14% vs. 13%), and recommendation (9% vs. 10.0%) remained stable, whereas child's lack of sexual activity decreased from 19% to 10% (p<.01). For males, lack of necessity (24% vs. 22%), recommendation (22% vs. 17%), and knowledge (16% vs. 14%), and child's lack of sexual activity (16% vs. 9%) and gender (13% vs. 2%) decreased from 2010 to 2016 (p<.05). Safety concerns increased (5% vs. 14%) (p<.01).

CONCLUSIONS

Vaccine messages should reflect current trends and focus on persistent concerns about knowledge, safety, and necessity, rather than sexuality and gender.

What explains the different rates of human papillomavirus vaccination among adolescent males and females in the United States?

PURPOSE

To identify factors that explain differences in HPV vaccination rates for male and female adolescents and to determine self-reported barriers by parents affecting vaccination decisions.

METHODS

The sample included adolescents 13-17 years old with a vaccination record documented in the 2012 and 2013 National Immunization Survey-Teen dataset. A logistic regression model was developed with 13 socio-demographic factors and survey year, along with significant interaction pairs with gender.

RESULTS

Subjects included 20,355 and 18,350 adolescent boys and girls, respectively. About half of the females (56%) received at least one dose of HPV vaccine, compared to 28% of males. Several factors differed between males and females, including higher vaccination rates among non-Hispanic Black males and lower vaccination rates for non-Hispanic Black females compared to Whites; and a stronger association with health care provider recommendation among males. The most common parental reasons for not vaccinating their children included 'not recommended by a health care provider' for males (24%), and 'unnecessary' for females (18%).

CONCLUSION

We found a significant gender interaction with several socio-demographic variables in predicting vaccination uptake. These gender differences may be partially an artifact of timing, because male vaccination became routine approximately five years after female vaccination.

HPV vaccination initiation after the routine-recommended ages of 11-12 in the United States

BACKGROUND

Since 2006, routine HPV vaccination has been recommended for females aged 11-12 in the US. However not much is known about the extent of and factors associated with HPV vaccination after the ages of 11-12.

METHODS

Provider-verified data on 8,710 females aged 13-17 were analyzed from the 2013 NIS-Teen survey. 2013 data was utilized since it was the first year one can fully evaluate the age at vaccination through age 17 for females who could receive the HPV vaccine at age 11.

RESULTS

Among HPV vaccinated females who were 17 in 2013, 47% (95%CI=43%-50%) received their first dose after age 12, and 24% (95%CI=21%-26%) received their first dose after age 14. The HPV vaccine was more likely to be initiated later than the meningococcal and Tdap vaccines (p<0.05), and later HPV vaccine initiation was more common among those having a more highly educated mother and those not receiving a check-up/well visit between the ages of 11 and 12 in adjusted analyses (p-values<0.05). Females initiating the HPV vaccine late were more likely to not receive three doses (RR=1.90, 95%CI=1.76-2.04).

CONCLUSIONS

HPV vaccination is commonly initiated after the age of 12 in the US, which could limit the vaccine's population-level effectiveness.

Disparities in Provider Recommendation of Human Papillomavirus Vaccination for U.S. Adolescents

PURPOSE

To determine the prevalence of and examine factors associated with provider recommendation of human papillomavirus vaccination for U.S. adolescents.

METHODS

Multivariable logistic regression analyses were performed using data from the National Immunization Survey-Teen 2014 on 34,478 adolescents aged 13-17 years.

RESULTS

Overall prevalence of vaccine recommendation was 72.6% for girls and 51.8% for boys. Lower rates were observed among girls aged 13 years, living below poverty line, adolescents of lesser educated mothers, and those residing in the South. Overall, girls had higher odds of vaccine recommendation (odds ratio [OR] = 2.57; 95% confidence interval [CI] = 2.35-2.82). Correlates of higher vaccine recommendation for girls were: older age-17 versus 13 (OR = 1.51; 95% CI = 1.20-1.89), living above versus below poverty line, and residing in Northeast (OR = 1.45; 95% CI = 1.21-1.73) and Midwest (OR = 1.29; 95% CI = 1.11-1.50) versus South. For boys, correlates of higher vaccine recommendation were: non-Hispanic black (OR = 1.30; 95% CI = 1.07-1.58) and Hispanic (OR = 1.24; 95% CI = 1.03-1.48) versus non-Hispanic white race and residing in Northeast (OR = 1.79; 95% CI = 1.54-2.08) and West (OR = 1.41; 95% CI = 1.17-1.70) versus South. Other factors associated with vaccine recommendation were having a college-educated mother and frequent doctor visits in the past 12 months.

CONCLUSIONS

This study highlights significant disparities in provider recommendation of human papillomavirus vaccination for U.S. adolescents. Findings suggest possible areas for tailored interventions to bridge the gap in vaccine recommendation and uptake in high-risk populations.

Factors associated with early adoption of the HPV vaccine in US male adolescents include Hispanic ethnicity and receipt of other vaccines

Adolescent males' HPV vaccine initiation and completion in the United States is far below the Healthy People 2020 goal of 80% 3-dose completion among boys. In 2012, less than 7% of males ages 13-17 years had completed the 3-dose series. The Diffusion of Innovations framework guided this investigation of factors related to early adoption of HPV vaccination among male adolescents. Provider-validated data from the 2012 National Immunization Survey-Teen (NIS-Teen) for male adolescents ages 13-17 years were analyzed via a multivariable Poisson regression to estimate prevalence ratios for factors associated with HPV vaccine initiation and completion. Adolescent males who are Hispanic and those who are up to date on other recommended adolescent vaccinations were most likely to complete the HPV vaccine. Public health interventions are needed to improve low HPV vaccination rates among adolescent males in the United States. Description of early adopters of the HPV vaccine provides historical context of HPV vaccination acceptance that is needed to inform the design of targeted vaccination interventions to prevent negative HPV-associated outcomes.

Geographic variation in human papillomavirus vaccination uptake among 13-17 year old adolescent girls in the United States

Geographic variation in provider-verified human papillomavirus (HPV) vaccine uptake among adolescent girls in the US has not been examined. To investigate this, we analyzed 2011 National Immunization Survey-Teen data. Among 13-17 year old girls (n=11,236), weighted vaccine initiation (48.4%) and completion rates (30.6%) were the lowest in the South when compared to the Northeast (53.4% and 39.9%), Midwest (51.1% and 33.5%) and West (61.6% and 38.7%) (P<.001, both for initiation and completion). Multivariable log-binomial regression analysis indicated that 13-17 year old girls living in the South were less likely to initiate [adjusted prevalence ratio (aPR)=0.86, 95% confidence interval (CI) 0.75-0.97] and complete (aPR=0.83, 95% CI, 0.74-0.93) the HPV vaccine series compared to girls living in the Northeast. Similar differences were observed when the uptake rates in the South were compared to other regions in the US. Intervention programs to increase HPV vaccine uptake and reduce regional disparities are warranted.