Around 37,000 new cases of cancer annually in the United States can be linked to human papillomavirus (HPV), particularly types 16 and 18 (1–3). The most common HPV-associated cancers seen in females and males are cervical and oropharyngeal cancer, respectively (1). While the onset of HPV-associated cancers is prevalent, a disproportionate burden is carried by certain populations, such as those from historically-underserved and minority backgrounds. Rates of cervical cancer are highest among Latine and American Indian/Alaska Native women, and lowest among white women (4). Furthermore, Black women face high mortality from cervical cancer–at almost double the rate of white women (5). This disparity has been associated with low follow-up cancer screening rates (i.e. Pap testing) and delays to care (6). Socioeconomic divides also increase HPV-associated cancer disparities, with cervical and penile cancers being strongly linked to living in poverty (7). Yet, these outcomes are largely preventable: through vaccination and controllable with adequate resources for cancer screening and follow-up.

The quadrivalent HPV vaccine, 4vHPV, that was approved in 2006 for females aged 9-26 resulted in an 88% decrease in cervical cancer among vaccinated females below the age of 17 over the span of two decades (8, 9). Currently, the nine-valent (9vHPV) vaccine, which was recommended for females and males aged 9-26 in February 2015, is the only HPV vaccine available in the United States (10, 11). In June 2019, the Advisory Committee on Immunization Practices (ACIP) updated its recommendation such that those aged 27-45 years can receive the vaccine following a “shared clinical decision-making” model with their healthcare provider (12, 13). Health insurance plans cover the cost of HPV vaccines; the federally-supported Vaccines for Children program offering additional financial coverage for those who qualify. In the United States, the HPV vaccine is generally available without cost to eligible individuals under certain circumstances. Most private health insurance plans are required by the Affordable Care Act to cover the vaccine as part of preventive care, without any copayment or deductible, when administered by an in-network provider. For individuals who are un- or underinsured, the vaccine is often made available through programs such as Medicaid for people under the age of 21, and the Vaccines for Children program for those who meet criteria. Additionally, adults aged 19-45 years who lack insurance and meet income eligibility requirements can access the vaccine without cost through the vaccine manufacturer’s patient assistance program (14, 15).

Despite the existence of a vaccine for nearly two decades, full protection against HPV by way of a complete vaccination dose remains unacceptably low in the United States: only about 61% of males and 65% of female adolescents aged 13-17 completed a vaccination series in 2022 (the most recent date for which data are available) (16). In accordance with ACIP guidelines, it is recommended that children aged 14 and younger complete a two-dose HPV vaccination schedule, while those aged 15 and older are advised to receive a three-dose series to ensure optimal protection against HPV-related diseases (12). These include some forms of cancer that are eligible for screening by way of a pap smear, such as cervical cancer. In other countries with similar gross domestic product and human development levels to the United States, rates of HPV vaccine completion for females (for example) vary based on program: Germany (51%), Canada (86%), Singapore (89%), and Australia (80%). In Canada, it is believed that strong school-based vaccination efforts have partly led to its success. In Singapore, HPV vaccination rates are thought to be high due to this country’s well-resourced public health initiatives (including public health education), and its healthcare infrastructure (17).

Numerous barriers to HPV vaccination continue to be reported, however–many of which are suspected to be rooted in social determinants of health. This terminology refers to a full spectrum of economic, environmental, and other factors (such as conditions into which people are born) (18). Examples include unsafe housing and neighborhoods, inadequate public transportation, racism, discrimination and violence, lack of education and job opportunities, and polluted air and water. Healthcare accessibility and affordability may further shape families’ health outcomes. This may be typified by the divide between rural and urban communities. Adolescents in rural areas have vaccination rates at least 10 percentage points less than those in more urban areas (19). Conversely, in a study by Ramphul and colleagues, they reported that HPV vaccination differs by community income levels, such that lower-income areas have higher vaccination (20). This “reverse disparity” has been reported previously as well (21). Social determinants that deter vaccination among young adult women include having lower levels of formal education and being less proficient in English. For men, lacking accessible primary care is commonly cited (22). Uninsured status and not seeing a healthcare provider in the past six months also decreases vaccination–underscoring the impact that systemic healthcare barriers play in HPV vaccination, and the need for expanded coverage (22).

Populations particularly susceptible to encounter these barriers are those from lower income Black and Latine communities. Vaccination rates are sub-optimal in pediatric primary care environments that serve these populations: only 41% and 20% of female adolescents from under-resourced Black and Latine communities report initiating and completing the vaccination series, respectively (23). While data show that lower income minority teens may be more likely to initiate vaccination relative to those who are white and come from higher-income households, they are less likely to complete the vaccination series (i.e., 2 doses for those under age 15; 3 doses for those older than 15) (24, 25). These levels of nonadherence to a multi-dose regimen are associated with a majority of low-income Black and Latine adolescents not receiving healthcare provider advice to vaccinate as often as other groups (25). Moreover, their providers are less likely to discuss and document sexual activity, exacerbating vaccine non-uptake (23, 25). Apart from provider recommendations, parents of adolescents who are from lower-income backgrounds, and those who are Black and Latine, report lacking information about the HPV vaccine and the importance of having to return for multiple doses (26). Parents who are Black and from lower-income backgrounds are also more likely to consider the HPV vaccine to be “new”, potentially contributing to misinformation and mistrust in the vaccine’s safety and efficacy (26). Among mothers who are Latine with lower socioeconomic backgrounds, less assimilation into United States society is associated with decreased vaccine uptake (27). According to the Centers for Disease Control and Prevention’s 2023 data, the prevalence of a completed HPV vaccine series for males and females (combined) among youth who are Black/African American was 59%, and for Latine was 63.6%, and for those living below the poverty level was 60.7% (28). These data suggest that more attention to cultural differences, and fostering trust in providers in the healthcare system, may be essential in understanding HPV vaccination behaviors among minority populations and offer clues to cancer prevention efficacy.

Due to the preventable nature of this cancer burden, and the vaccination barriers experienced by lower income families who are Black and Latine, our study sought to better describe their experiences with HPV vaccination. We did this by surveying populations in the greater Washington, DC (4.3 million people, 31% Black) and Hackensack, NJ (2.2 million people, 33% Latine) Census Bureau regions, where pronounced cancer disparities are known to exist. Vaccine initiation rates among youth ages 13-17 in the greater DC region is 84.6% in females and 80.8% in males: across the state of NJ, average rates are 73.4% in females and 77.5% in males (28). What is not yet known, however, are HPV vaccination prevalence rates among children and their vaccine-eligible parents who are living in families subsisting below the federal poverty line, and for whom targeted and tailored interventions do not exist. According to the World Health Organization (WHO), individuals living below 60% of the regional median household income are considered to be at heightened risk of health disparities, highlighting the critical need for more focused health initiatives in these communities (29). In the United States, regions with median household incomes of $96,346 in New Jersey and $111,000 in Washington, DC illustrate the financial challenges faced by many communities, which can contribute to barriers in healthcare access and exacerbate health disparities (29). We anticipated that HPV vaccination would be even less among these populations who were lower income and minoritized (i.e., Black and Latine) than state-wide community prevalence estimates suggest, and despite a school vaccination mandate in DC, partly due to numerous social determinants of health and other access burdens that families living in these areas commonly experience. Reported herein are parent-child HPV vaccine initiation rates, factors contributing to its uptake, vaccine hesitancy and medical mistrust, and vaccination intentions, as well as reasons for not vaccinating.

This study, which focused on financially distressed and racially and ethnically diverse communities in DC and NJ, revealed remarkably low HPV vaccination prevalence among both vaccine-eligible parents (20%) and their children (37%). Importantly, and has not often been reported in the prior literature, approximately one-third of adults could not recall their own vaccination status, and about half could not recall their children’s. Reasons for this lack of awareness are unknown. On the one hand, it may reflect low levels of health literacy within this population, a lack of engagement with healthcare and/or healthcare providers, and/or a lack of contextual cues to adequately recall one’s own or one’s child’s vaccination history. On the other hand, it may be reflective of a larger and more systemic phenomena that deserves further study of how to support these parents in understanding their own and their children’s health. Regardless of its cause, the consequences remain the same: parents and children in these communities are underserved from a vaccination perspective, with missed opportunities to educate and inform about HPV vaccination and the delivery of this care to those most in need.

In this study, social determinants of health played a significant role in the findings because parents who identified as non-white, and had unvaccinated children, exhibited the lowest vaccination rates. Moreover, children of these parents who were unvaccinated and whose parents possessed lower levels of formal education, were less likely to have initiated an HPV vaccination series. Parental decisions to forego vaccination on their own and/or their child’s behalf are multifaceted, including: a lack of awareness about HPV and the vaccine (34.5%), uncertainty regarding vaccine safety (15.5%), and the perception that a child’s sexual activity status determines vaccination necessity (13.1%). Child vaccination rates within families from lower-income and minority backgrounds reveal influences of systemic barriers as well. It was expected that the child vaccination rate in these families would be lower than national averages. This likely arises from the presence of social determinants of health barriers, such as financial insecurity or unsafe living environments, that, unfortunately, deter access to high quality healthcare for these individuals (35, 36).

The intersecting nature of structural barriers and social determinants of health within these communities contributes to a concerning lack of access, exacerbating disparities in healthcare utilization. One consequence of this limited access is a decreased awareness of HPV and a subsequent underutilization of the vaccine as a method of primary cancer prevention. This trend is especially pronounced among populations facing the highest cancer mortality rates, further emphasizing the impact of these forces on their health outcomes (5, 37). The net result of inadequate access extends beyond the immediate implications for HPV vaccination. Notably, diminished awareness of HPV within these populations poses an ongoing public health challenge (38). A lack of knowledge about the virus and preventive measures also hamper efforts to curb the spread of HPV-related cancers that contribute to higher mortality rates within these already vulnerable communities (39).

Encouragingly, most surveyed parents with currently unvaccinated children expressed an intent to vaccinate them within the next year. Even among parents with lower levels of formal education, these data demonstrated how a trusting relationship with a healthcare provider would boost the likelihood that parents were receptive to vaccinating their sons and daughters over time, with a one-unit increase on the provider trust scale correlated with a 0.35 point increase in vaccination intent. This is important because of the well-established relationship between behavioral intention to vaccinate and HPV vaccination behavior that is posited by models of health behavior change (40, 41). The impact that intention to vaccinate has on vaccine uptake suggests that forming trusting relationships holds great potential to reduce cancer-related health disparities. Yet, parents’ formal education level should not determine which vulnerable groups are more equipped with the knowledge necessary to make informed choices about their own and their children’s healthcare.

From a policy perspective, the United States has already established national benchmarks for HPV vaccination as part of its Healthy People initiative (42). Unlike other countries around the world, the United States has maintained a multi-dose regimen of the HPV vaccine which, while providing full coverage, places additional burdens on families least likely to medially adhere to this recommendation (43, 44). Whether or not moving from a multidose to single dose regimen would eradicate HPV-linked cancers in the United States (as trends outside the United States suggest) remains to be seen (45, 46).

HPV vaccination has been marked by hesitancy since its introduction in 2006. Nearly a quarter of parents in the United States still harbor feelings of hesitancy toward the HPV vaccine for their children (47). Our own data suggest multiple barriers that families from under-resourced communities confront when vaccinating their children against HPV. These included how informed families are about HPV and the benefits that come from vaccination, concerns with vaccine safety, and their children’s sexual activity level/perceived ‘need’ to vaccinate. Importantly, our data focus on vulnerable populations—underscoring and magnifying these findings from a cancer prevention perspective (48–50). Although provider recommendation is consistently observed as a driver of children’s vaccination, our analysis revealed that this provider recommendation should be accompanied by a solid foundation of trust with that provider. When communities have been overlooked and marginalized, the cumulative effect of that disenfranchisement on their health and social well-being is especially pronounced. In the current climate of social change taking place across the country, there is a renewed optimism and opportunity to repair broken relationships with families from underrepresented backgrounds, especially families like those included in our study.

This study recognizes the importance of joining with individuals where they are in their readiness to vaccinate to promote health outcomes, especially for those from lower income and minority communities. Tailoring interventions to address the concerns and medical mistrust dynamics within these communities is likely essential for overcoming persistent hesitancy and increasing vaccine acceptance. This multilevel approach involves culturally and developmentally appropriate health communications, community engagement, and educational campaigns. To effect positive change on HPV vaccination rates, it is encouraging to look at successful interventions that have addressed similar challenges. For instance, an intervention involving emailed HPV vaccine reminders in both English and Spanish significantly increased vaccine initiation among Black, Hispanic, and Asian adolescents (51). These successes may provide a blueprint for how tailored interventions can effectively address discrepancies in vaccination rates in the United States. With respect to other countries, including those with health systems that differ from those found in the United States, it would be important to understand how these types of interventions would need to be adapted to not only account for individual influences, but also social and institutional factors affecting HPV vaccination rates in those settings.

Suboptimal prevalence of HPV vaccine uptake was observed among parents and children in lower-income communities and racial/ethnic minority groups in the regions studied. Recognizing these social determinants of health barriers is essential for informing targeted interventions. Strategies should include comprehensive education initiatives and facilitated program access to address disparities and improve vaccine acceptance within these populations to control their cancer burdens.