ASK THE EXPERT

Question: I recently heard about HPV vaccinations for males. Is this an evidence-based practice? What are the considerations for vaccinating boys and men?

Tami Thomas and Samuel Snell, Honor Student, respond: The prevalence of human papillomavirus (HPV) infection is increasing in the United States in both low-risk and high-risk groups of men; so, it is imperative that pediatric nurses educate and encourage HPV vaccination for boys (Smith, Gilbert, Melendy, Rana, & Pimenta, 2011). HPV is estimated to currently infect young men 20 years of age and older at rates between 65% and 93% in high-risk populations, and up to 45% among lower risk populations. Despite the usefulness of the vaccine in preventing HPV-related cancers in men, barriers to HPV vaccination still persist (Smith, Gilbert, Melendy, Rana, & Pimenta, 2011). The benefit of the HPV vaccine in boys is often over-looked by the initial focus and marketing of the HPV vaccine as a means to prevent cervical cancer. There is also a lack of knowledge about the virus, such as the fact that more than 130 HPV genotypes exist, and that they are classified as low-risk and high-risk types (Frazer, 2010). Low-risk types (i.e., types 6 and 11) cause genital warts, while high-risk types (i.e., types 16 and 18) can cause cancers of the cervix, anus, oropharynx, penis, vagina, and vulva (Marklund & Hammarstedt, 2011). Current data indicate that HPV infection may be associated with 96–99% of cervical cancers, 90–93% of anal cancers, 12–63% of oropharyngeal cancers, 36–40% of penile cancers, 40% of vaginal cancers, and 40–51% of vulvar cancers (Hernandez et al., 2008; Kroger, Atkinson, Marcuse, & Pickering, 2006; Marklund & Hammarstedt, 2011; Parkin & Bray, 2006; Watson et al., 2008). Vaccinating boys and men ages 9–26 years can prevent more than 5 million cases of genital warts and 40,000 cancer-related deaths over the next century, while saving $25,700 per quality-adjusted life year (Schiller, Day, & Kines, 2010).

HPV INFECTION AND TRANSMISSION

HPV exhibits a unique mechanism of infection, leading to the development of cancer in high-risk types 16 and 18 (Schiller et al., 2010). Papillomaviruses are the only known viruses to initiate infection and then invade cells by interacting with a surface of the cell to invade it (Schiller et al., 2010). Once HPV has invaded a basal cell, it takes approximately 24 hr for HPV’s genetic material to be integrated with the basal cell’s nuclear DNA (Schiller et al., 2010). Transcription and translation of HPV’s genetic material in the basal cells results in the production of several viral proteins that affect the disease process (Schiller et al., 2010). High-risk HPV types express two proteins that are not consistently expressed in low-risk HPV types (Münger & Howley, 2002). These two proteins, L1 and L2, are directly linked to oncogenesis or the production of cancerous cells (Francis, Schmid, & Howley, 2000) and to the promotion of growth of the invaded skin cell (Münger & Howley, 2002), which is another critical step in HPV’s transmission cycle (Conway et al., 2009). L1 and L2 promote the binding of HPV’s capsid or “outer cap/layer” to the basal membrane and basal cells of future hosts, such as cervical cells, cells on the base of the tongue, and the oral pharynx (Schiller et al., 2010).

VACCINE-INDUCED PROTECTION AGAINST HPV

Early evidence showed that natural immune antibodies to HPV targeted the L1 protein; thus, Cervarix (GlaxoSmithKline, Research Triangle Park, NC, USA) and Gardasil (Merck Pharmaceuticals, Whitehouse Station, NJ, USA) vaccines were developed to induce recognition of and antibody protection against the L1 capsid protein. However, L1’s expression is varied, and so there is limited protection because of the diminishing amount of cross-type protection or protection for HPV types other than the specific HPV types induced by vaccines (Day et al., 2010). Consequently, the Cervarix vaccine only induces immunity against HPV types 16 and 18 (the two most common DNA types that cause cancer), and Gardasil only induces immunity against HPV types 6, 11, 16, and 18 (Centers for Disease Control and Prevention [CDC], 2011). Vaccination generates an antibody response that plateaus 12 to 18 days after vaccination and then declines until the subsequent vaccinations (second and third shots) in the HPV vaccination series are completed (Frazer, 2010). Statistical modeling of the immune system’s response to L1 protein antibodies predicts sufficient immune memory to recognize and respond to future HPV challenges for 32 years in 50% of a population receiving a three-dose vaccine regimen, so the HPV vaccine may save boys and men from HPV-related cancer for many years after they receive the completed HPV vaccine series (Fraser et al., 2007). Current evidence confirms that vaccine-induced immune memory of the L1 protein remains strong enough at 7 years to respond reliably to a new HPV infection (Moscicki et al., 2012).

While HPV types 16 and 18 are the two most common cancer-causing HPV genotypes, their distribution internationally is substantially varied, accounting for 79% of carcinomas in North America and 68% in Africa (de Sanjose et al., 2010). Consequently, there is a second generation of HPV vaccines that are being developed, which target the L2 capsid protein to provide broad, cross-type immunity, because the L2 capsid protein is more highly conserved across HPV types. Thus, this next generation of HPV vaccines may cover more DNA types than 6, 11, 16, and 18 (Day et al., 2010).

BARRIERS TO HPV VACCINATION IN BOYS: THE RURAL GAP

Current data indicate that HPV vaccine uptake in boys continues to be low, only 10–12% nationally, despite the CDC’s recommendations and the demonstrated efficacy of the vaccine (Giuliano et al., 2011; CDC, 2011).Therefore, understanding how to promote HPV vaccination of boys is a public health priority. Regrettably, the prevalence of HPV in rural areas is particularly problematic as it continues to out-pace rates found in urban and suburban areas, and the rural–urban gap in HPV-related cancers is expanding (Chou, Krill, Horton, Barat, & Trimble, 2011). Research also suggests that HPV vaccine acceptability may be even lower among male adolescents and preadolescents belonging to certain vulnerable populations, such as Latino cultural subgroups and boys living in geographically isolated areas (Thomas, Stephens, Johnson-Mallard, &Higgins, in press; Thomas, Strickland, Diclemente, & Higgins, 2012).

More generally, men’s perceptions of the hassle and cost of vaccination, self-efficacy required to get it, and perceived social and cultural norms are strongly linked to vaccine acceptability and uptake in men (Kim, Andres-Beck, & Goldie, 2007). Preliminary research has demonstrated that these factors contribute to low HPV vaccine acceptability among adolescents; further, adolescent males with less HPV knowledge have been shown to have higher levels of shame and to be less likely to engage in preventive health behaviors such as vaccination (Das et al., 2010; Dorell, Yankey, & Strasser, 2011; Gerend & Magloire, 2008).

To complicate the matter, primary care offices in many underserved areas limit requests for HPV vaccines from the state’s health department because the cost of stocking the vaccine must be offset by the amount of vaccine requested. If parents do not perceive any benefit to HPV vaccination or understand the link between persistent HPV infection and HPV-related cancer, then there will be no demand for the vaccine. This is particularly profound in areas where the rate of parental requests for the HPV vaccine is not high enough or predictable enough to reliably stock a vaccine before it expires. For example, in the rural areas where HPV research has been conducted, boys and young men must travel over an hour to access the HPV vaccine. This certainly discourages vaccination, and it is well beyond the accepted 30-min drive time for establishing reasonable healthcare access (Guagliardo, 2004). Further, while boys in urban areas may be able to use public transportation to access the HPV vaccine, boys in rural areas may not have access to public transportation and may not have a car due to family financial constraints, even if they are of driving age. Consequently, this highlights the pivotal role that both pediatric nurses and parents play in initiating the HPV vaccination, to protect these young boys and men against HPV-related cancers. Positive parental attitudes are central to HPV vaccine uptake in boys because parents are the decision-makers. Research initially implied that parents were influenced by fears that the vaccine instigates or encourages early sexual activity and by parental preference to wait until teens are sexually active (Smith et al., 2011). There is new evidence, however, showing that risk factors for teenagers are not adequate predictors of HPV infection, and sexual risk taking does not increase following HPV vaccination of girls (Liddon, Leichliter, & Markowitz, 2012; Smith et al., 2011).

INCREASING HPV VACCINATION OF BOYS: A FAMILY-CENTERED APPROACH

To increase vaccination rates for boys, we recommend nurses use family-centered strategies to increase parents’ knowledge of HPV vaccination, including awareness of the new HPV immunization guidelines from the Advisory Committee on Immunization Practice (ACIP) at the Centers for Disease Control and Prevention (CDC), which recommends three doses (shots) over 6 months, with the second dose given 1–2 months after the first, and the third dose given 6 months after the first dose (CDC, 2011). It is also critical to establish parental awareness of the pathology associated with HPV, including the increasing rates of mouth, head, and neck cancers secondary to HPV infection (Thomas et al., 2012). Additionally, parental misperceptions and misinformation, such as a belief that the HPV vaccine leads to or condones sexual activity or risky behaviors, must be addressed. Of particular concern in our efforts to educate are underserved populations, where geographic, cultural, and economic disparities complicate both a boy’s experience with HPV infection and his parent or caregiver’s decision to initiate his/her son’s HPV vaccination. For example, parents residing in rural areas are frequently suspicious of outsiders and resistant to healthcare innovations like the HPV vaccine (Rosenthal et al., 2008). Therefore, it is important to view parents as members of social networks that are entwined with one another and embedded within their unique cultural milieu.

The role of parental gender and race in the HPV vaccine uptake decisions must also be kept in mind, for example, the embodiment of most African Americans’ extended family model (LeCuyer, Swanson, Cole, & Kitzman, 2011). We recommend that nurses working with African American parents adopt a broad definition of family when designing interventions to promote vaccinating boys with the HPV vaccine, such as inclusion of extended family members and the influence of social networks developed through church attendance. This broad definition of family is particularly pertinent to African Americans in rural areas, where the confluence of low income, low parental education levels, few social supports, and variable work schedules influence child-rearing beliefs and practices that are often based on social experiences outside the extended-family paradigm (Lanza & Taylor, 2010). Vaccinating boys with the HPV vaccine can and should start with fathers or those men considered father figures for young men, because research substantiates that young boys will seek advice from fathers and father figures regarding health and sexual issues (Wilson & Koo, 2010). Father-focused health education interventions should address the perception that administration of the HPV vaccine represents permission to engage in sexual activity. Research findings from Liddon, Leichliter, and Markowitz (2012) clearly show that HPV vaccine administration does not lead to or promote risky sexual-activity behaviors. Further, as young boys turn 18 years of age, they no longer need parental permission for vaccination. But when fathers or father figures are included in healthcare decision-making for their sons, initial discussions should always begin with increasing knowledge about HPV infection and their own vulnerability to HPV infection. It is also important that men, fathers, and father figures understand that HPV infection and related HPV cancers are not just “women’s diseases.” In addition, when parents are involved in education, health promotion can include messages such as, “the HPV vaccine is just as important for the future health of a boy as it is a girl.”

To summarize, when pediatric nurses are discussing HPV vaccination of boys, three important points should be discussed: (a) HPV is spread by skin-to-skin contact; (b) HPV vaccination prevents cancer; and (c) Studies show that HPV vaccination does not promote sexual promiscuity. Nurses can improve the future health for all children, both boys and girls, by educating the general public and increasing awareness that HPV vaccination is for boys.

In the future, specialists in pediatric nursing can build on current research findings that imply a cross-gender gap in HPV knowledge and vaccination intention; that is to say that like race, the gender of the child influences decision-making in vaccination (Thomas, et al., 2012). Likewise, other areas of research interest can focus on parents living in underserved areas who were noted to be more likely to vaccinate their sons than their daughters as a consequence of the influence of cultural norms (Thomas, et al., 2012). The answer to the question, “Vaccinate boys with the HPV vaccine?” is a resounding yes. Nurses who use a comprehensive approach communicating with messages that are culturally specific and account for regional cultural norms of each family can contribute to the health and well-being of all pediatric patients.