Despite the availability of safe and effective vaccines against HPV types that cause most cervical and other HPV-related cancers, vaccine uptake in the U.S. is suboptimal [1]. Routine HPV vaccination is recommended at 11–12 years of age, with catch-up vaccination through age 26, yet only 72% of 13–17 year old adolescents had received ≥1 dose and 54% had completed the series as of 2019 [2].

Racial and ethnic minorities face barriers to HPV vaccination such as disparities in knowledge about HPV and HPV vaccines [3], parental awareness [4], and lack of provider recommendation [5]. A recent meta-analysis showed that Black, Hispanic, Asian, and other ethnic minority adolescents combined are 6.1% (95% CI: 3.3–8.8%) more likely to initiate the HPV vaccine series than their White/non-Hispanic counterparts; however, they are 8.6% (95% CI: 5.6–11.7%) less likely to complete the series [6]. Several studies indicate that adolescents whose caregivers are foreign-born are less likely to receive HPV vaccine than adolescents with U.S.-born caregivers [7–9]. HPV vaccination in East African immigrant communities is understudied, but limited data suggest very low uptake and limited vaccine awareness [10, 11].

Interventions targeted to adolescents may increase HPV vaccine uptake by addressing concern about pain [12] or limited HPV-vaccine knowledge [13], and can be adapted for specific communities. Educational interventions developed for adolescents have included video games [14], leaflets [15], and interventions delivered in school-based settings [16], such as activities, magazines and films [17], face-to-face structured information [18], and real-time teleconferencing [19]. While most improved vaccine-related knowledge and/or intentions, impacts on HPV vaccine uptake were variable or not evaluated.

Comic books are another type of educational tool and are especially relevant in adolescent health promotion because the use of visual story with text improves comprehension and retention, while engaging the reader [20, 21]. Comic books have been used successfully to improve health knowledge and behaviors in tobacco cessation and obesity prevention [22, 23]. Previously, Katz et al. developed and piloted a comic book related to HPV vaccines for adolescents in rural Appalachian communities [21]. However, no studies have developed or evaluated the impact of an HPV vaccine comic book for East African-American (EAA) adolescents.

We developed a comic book [24] as a part of a multi-level intervention study targeted to EAA communities in Washington State involving mothers, adolescents, and healthcare providers [25, 26]. This paper describes the impact of the comic book on adolescents’ knowledge of HPV/HPV vaccines, beliefs about and intention to receive HPV vaccination, as well as HPV vaccination uptake within 6-months post-intervention.

We developed a comic book for 14–17 year old EAA adolescents [24]. Between 2017–2018, the comic book was evaluated among adolescents who attended ethno-linguistic-specific community dinners (8 in Somali language for Somali communities and 2 in Amharic language for Ethiopian communities) with their mothers in King County, Washington. The study was approved by the University of Washington (STUDY00000785) and Washington State (2019–047) Institutional Review Boards.

Our analysis included 136 adolescents (belonging to 84 mothers). 64 adolescents were assigned to the pre-test and 72 to the post-test. Overall, about two-thirds (68.4%) were 14–15 years old and most (90.3%) were Somali. Just over half (53.7%) were female and just over half (52.4%) were born outside of the U.S. Most (90.3%) of their mothers identified as Muslim and 59.7% of their mothers reported annual household income <$25,000 (Table 1).

The comic book intervention had a positive impact on EAA adolescents’ HPV and HPV vaccine knowledge and beliefs, social norms around peer and healthcare provider attitudes towards the HPV vaccine, and parental communication. Adolescents surveyed after viewing the comic book were more than twice as likely to say that they were willing and likely to receive the HPV vaccine than those surveyed at baseline.

Comic books have been used to address diverse health promotion topics[21, 33–35]. They have been evaluated as interventions to decrease tobacco use among American Indian and Alaskan Native youth [33], for HIV/STD risk-reduction among South African adolescents [35], and to increase family planning among female Kenyan adolescents [34]. However, most studies have measured acceptability of comic books, but not resulting changes in knowledge or behavior [21, 33]. An exception is the Kenyan study that found that exposure to the comic book intervention was associated with delayed first sex and first pregnancy [34]. The comic book developed by Katz et al. for HPV vaccine uptake in the U.S. included similar constructs as ours but its impact on adolescents’ knowledge and beliefs about HPV vaccine has not been evaluated [21]. Our study demonstrates that a culturally-adapted comic book that integrates parental feedback can improve adolescents’ knowledge, beliefs and intentions to receive HPV vaccine.

Pain, distress, and/or fear about needle procedures is common among adolescents [36]. The HPV vaccine has received negative media attention about reports of high rates of pain and syncope [37]. We did not observe a positive impact on concerns about pain, perhaps because the comic book acknowledged pain as a necessary consequence of vaccination. However, adolescents surveyed after viewing the comic book were more likely to be unconcerned about side effects compared to adolescents surveyed at baseline, indicating the intervention was successful in overcoming an important barrier to vaccination.

The comic book positively impacted social norms related to peer and health care provider attitudes. Notably, only about half of the post-intervention group agreed that their peers think it is a good idea to get vaccinated, compared to 87.5% who answered that their providers would think it is very important to receive the vaccine. Very little information is available as to how adolescents’ peer perception of HPV vaccine affects their own behavior. This is a significant evidence gap, as peer group acceptance becomes increasingly important in adolescence [38], with potential to influence behavioral patterns that may continue into adulthood [39]. In one study, adolescents and their caregivers in rural Alabama identified peer testimonials and recommendations as a potential facilitating strategy to increase HPV vaccine uptake [40]. More research about how adolescents’ peer perceptions affect HPV-related beliefs, stigma and the decision-making process would be important for developing future interventions that specifically act on the mechanism of change to increase adolescent HPV vaccine uptake [41].

Although our study was not designed to evaluate the impact of the comic book on HPV vaccine uptake, only two adolescents were vaccinated in the 6-months post-intervention despite the positive impact on HPV vaccine intentions. There is growing evidence that while interventions based on the Health Belief Model may positively influence vaccine intention, their effects on behavior are inconsistent and minimal [42], and that vaccine intentions are an unreliable predictor of uptake [16]. Evidence suggests that vaccine uptake involves a multi-faceted decision-making process, which requires multi-level and multi-modal interventions [16, 41]. For example, most adolescents rely on their parents or caregivers to access healthcare; therefore, parents’ interest or willingness to have their children vaccinated influences whether or not adolescents receive the HPV vaccine. Netfa et al. found that while many immigrant parents had negative attitudes towards HPV vaccination because of the potential for sexual promiscuity and side effects, the majority of parents had positive attitudes after they were informed about the vaccine [43]. Lott et al. noted parental involvement is likely a facilitator to improved vaccine uptake in some minority populations, while it is a barrier in others [44]. Our findings suggest that when HPV vaccination is approached with cultural sensitivity, it is possible to enhance the level of comfort for the adolescents to have a conversation about HPV vaccines with their parents.

A strength of our study is that the comic book was developed with the EAA communities’ input through a multi-methods process involving focus groups with mothers [27]. Given the heterogeneity within minority groups, it is important to design interventions and studies tailored for the unique intersectionality of the participants’ racial, ethnic and cultural identities [44].

Our study had limitations. First, the quasi-experimental pre-/post-test design could have reduced the validity of the findings. We assigned participants to either a pre- or post-test to reduce testing bias, but allocation was not randomized. Furthermore, we adjusted for select demographic variables to control for confounding, but there may have been residual or unmeasured confounding. Secondly, sampling bias could have occurred, because adolescents were not recruited directly but were brought to the dinner events by their mothers. Therefore, they may have perceived their environment as vaccine-friendly, which could have influenced their intention to receive HPV vaccine. Moreover, mothers who agreed to participate in the study and their children may be different from those who did not, which may limit generalizability of the findings. Participating mothers may be more health conscious or motivated to learn about HPV vaccine than other mothers in their community. Our sample size was small, and it was not possible to look at effect differences by ethnicity because most participants identified as Somali. We found that the impact of the comic book tended to be stronger in males than in females (likely due in part to lower baseline knowledge in males than in females) but did not have sufficient power to test for effect modification. We may not have captured all adolescents vaccinated post-intervention due to possible incompleteness of the WAIIS registry, or mismatches between names of children reported by their mothers and in the registry. Lastly, because the post-test was conducted immediately after the intervention with no follow-up assessments, we were unable to assess knowledge or attitude decay that could have occurred over time.

In conclusion, a culturally targeted comic book for EAA adolescents effectively improved HPV vaccine related knowledge, beliefs, and intentions. The comic book can easily be adapted and replicated in other communities with low HPV vaccine uptake. Additional research in EAA communities on strategies that may act synergistically with adolescent education to increase HPV vaccine uptake (such as reminders [45], referral and/or navigation support for scheduling vaccination appointments [46], or leveraging community-clinical partnerships [47]) is warranted.