Variables Associated With Human Papillomavirus (HPV) Vaccine Acceptance by Men

Methods

Results

Of approximately 650 men who were asked to volunteer, complete data were available for 571 men. Insufficient time to complete the survey and general lack of interest were the most common reasons for nonparticipation. Detailed demographic data have been previously published.¹⁸ However, in summary, most men were white (61.0%) with at least a high school education (96.5%) and younger than 30 years old (69.2%). Approximately half (52.1%) had a family income of less than $50,000 per year and the majority (86.6%) had some type of medical insurance. Almost two-thirds (64.2%) were of the Protestant faith. Most men (63.6%) were single and 94.9% claimed to be heterosexual. Nearly three-quarters (74.4%) were sexually active and 83.1% had initiated sexual activity by the age of 18. Only 2.3% had a history of genital warts.

Of the 571 subjects, 33% wanted to be vaccinated against HPV, 27% did not, and 40% were undecided.¹⁸ We compared demographic data with HPV vaccine preference to determine correlates of vaccine acceptance among men (Table 1). Differences in wanting to get the HPV vaccine were found for various demographic variables, including age, race, education, martial status, wearing a seatbelt, and using tobacco. A greater percentage of men who did not want to get the vaccine were older (P = .0009), black (P = .0003), and had a lower education level (P < .001). Men who were undecided about receiving the vaccine were more likely to be younger and white. Being a college graduate or Hispanic were positive correlates for vaccine acceptance. Men who were undecided about receiving the vaccine were more likely to be single and men who did not want the vaccine were most likely to be living with a partner (P = .02). Men who want the vaccine were more like to wear their seatbelt most of the time (P = .018). Regular use of tobacco correlated positively with vaccine acceptance (P = .001).

We also compared men's sexual history with HPV vaccine preferences (Table 2). Other differences for wanting to receive the HPV vaccine were seen for the variables of being sexually active, lifetime number of female sexual partners, oral sex, and frequency of sex. Men who wanted to be vaccinated were more likely to not be currently sexually active and men who were undecided about vaccination were most likely to be virgins (P = .0008). Men with the greatest lifetime number of female sexual partners were most likely to want the vaccine (P = .0004). Not engaging in oral sex was a positive correlate of vaccine acceptance (P = .045). Virgin men were most likely to be undecided about receiving the vaccine (P = .028). No significant correlates for vaccine acceptance were found for the type of contraception or protection used or a history of genital warts.

Men's feelings and knowledge about HPV and the HPV vaccine were analyzed as correlates of HPV vaccine acceptance (Table 3). Five variables were found to be significant correlates of vaccine acceptance, worry about vaccine side effects, concern about vaccine safety, the importance of getting vaccines, familiarity with the HPV vaccine, and the importance of getting the HPV vaccine. Men desiring vaccination were more likely to be extremely worried about vaccine side effects (P < .0001) and less likely to be not concerned at all about vaccine safety (P < .0001). Those men not worried about vaccine side effects or vaccine safety were most likely to be undecided about being vaccinated. Men who feel it is extremely important to get vaccines were also more likely to want the vaccine (P < .0001). Greater familiarity with HPV positively correlated with vaccine acceptance (<.0001). Similarly, feeling it is extremely important to get the HPV vaccine positively correlated with desire to be vaccinated (P < .0001).

Factors that may affect men's willingness to receive the HPV vaccine were also examined (Table 4). Men were more willing to be vaccinated if their doctor recommended it (56.0%), if it was free (51.4%), and if research proved the vaccine will be helpful for men (50.7%). Other reasons are listed in Table 4.

Discussion

Men's correlates of HPV vaccine acceptance have not been previously determined. Some may argue that men do not need the HPV vaccine. These people may appreciate the burden of HPV disease in women but fail to understand the magnitude of HPV-related disease in men. However, there are several reasons why vaccinating boys and men against HPV can be beneficial. First, the vaccine can prevent many HPV-related conditions, including penile, anal, and head-and-neck neoplasias; genital warts; and recurrent respiratory papillomatosis. By preventing these potentially life-threatening diseases and infections that produce significant morbidity, boys and men can live healthier lives.¹⁹ Prophylactic vaccination may also reduce health care costs for men. Moreover, by vaccinating boys and men in addition to girls and women, society and individuals benefit from herd immunity. A gender-neutral vaccination program to prevent HPV makes good sense.

With respect to age, younger men were more likely to be undecided about receiving the HPV vaccine and older men were more likely to not want the HPV vaccine. Education about HPV and the HPV vaccine will be critically important for young men, those at greatest risk, to accept vaccination. Women are probably more familiar with HPV because of their frequent screening examinations for cervical cancer and the recent media publicity about the quadrivalent HPV vaccine. Like with older mid-adult women, more older men see no need for vaccination.¹⁶

In general, more white men were undecided about vaccination and a greater percentage of black men were opposed to vaccination. However, compared with white men a greater percentage of black men wanted to receive the vaccine. We cannot honestly explain these findings so must leave the rationale to speculation.

A greater amount of education correlated positively with a desire to receive the HPV vaccine. Men with a higher level of formal education were perhaps better able to understand their risk of infection and the importance of a prophylactic intervention. Although future HPV vaccine education should target all men, an emphasis on those without a college degree may be particularly beneficial.

Being single correlated positively with indecision about receiving the vaccine. Although marital status is somewhat irrelevant to all other vaccination programs, we detected some hesitancy by unmarried men. Reluctance at the present time is justified given the lack of clinical trial data and approval by the FDA. A global vaccination policy for all boys, combined with ample education for men, may adequately address this current problem of indecision.

Health behaviors were also examined as correlates for vaccine acceptance. Use of a seat belt most of the time correlated positively with a desire for vaccination. Interestingly, men who wore seat belts all the time were more likely to be undecided about vaccination. Perhaps those most cautious about automobile safety were equally cautious about accepting a vaccine before reviewing safety and efficacy data in men. Men who used tobacco products regularly were more likely to want the vaccine. This group response is particularly encouraging because tobacco use has an adverse effect on the immune system's response to HPV infection.²⁰ Smokers are less likely to clear HPV infection and have an increased risk for cervical neoplasia.^21,22

Interesting correlates of vaccine acceptance were also seen when men's sexual history was examined. Men who were not currently sexually active were more likely to want the HPV vaccine. However, male virgins were more likely to be undecided about vaccination. In the former case, nonvirgins not currently sexually active perhaps were aware of potential risks and saw a window of opportunity to be protected. Unfortunately, male virgins did not fully comprehend the ideal time to be vaccinated was before initiating a sexual relationship. Although this may not pose difficulties for sexually naïve young boys receiving the HPV vaccine, it identifies a special educational challenge for vaccinating a catch-up population of male virgins. Men with a history of more than 10 female sexual partners were also more likely to want the HPV vaccine. Although this risk profile for potential existing HPV infection minimizes the possible attributes of the vaccine, these higher-risk men clearly appreciated the need for vaccination. Although not statistically significant, the same trend was noted for men who have sex with men. Men reporting 5 or fewer sexual partners were more likely to be undecided about receiving the vaccine. Once again, much education will be necessary for this population because vaccination would be more beneficial in this lower-risk group of men. Men who had oral sex were more likely to be undecided about vaccination, but men who had not had oral sex were more likely to want the HPV vaccine. No significant correlates were noted for a history of vaginal and anal sex. The implications for these types of sexual activity and desire to be vaccinated are not completely understood. With respect to sexual frequency, men who never had sex were more likely to be undecided about vaccination. Again, the virgins perhaps did not appreciate the same urgency for vaccination as sexually experienced men.

Several feelings toward all vaccines and the HPV vaccine and knowledge of HPV were found to correlate positively with HPV vaccine acceptance. Men who were extremely worried about vaccine side effects or extremely concerned about vaccine safety were more likely to want the HPV vaccine. These same men may have been extremely concerned or worried about the risks of HPV infection and, therefore, for them vaccination is preferable. Men who were not worried about the vaccine side effects nor concerned about vaccine safety were more likely to be undecided about receiving the HPV vaccine. These aloof men could also benefit from special education about receiving the HPV vaccine. Men who felt it extremely important to get vaccines, in general, also were most likely to want the HPV vaccine. This expected positive correlation helps to validate our survey. Those who felt it was unimportant to get vaccines were most likely to be undecided about HPV vaccination. Familiarity with HPV also correlated significantly with HPV vaccine acceptance. Men very familiar with HPV were most likely to want the HPV vaccine. Similarly, those men not familiar with HPV were more likely to be undecided about HPV vaccination. These data underscore the importance of educating men about HPV to insure a successful vaccine implementation program for men. As anticipated, men who felt it was extremely important to get the HPV vaccine were most likely to want to receive the HPV vaccine. Thus, educational efforts must convey the importance of receiving the HPV vaccine.

When asked which factors would most influence men to receive the HPV vaccine, more than half of the men stated they would be more inclined to receive the vaccine if recommended by a doctor. Parents of adolescents also indicated that a positive recommendation by their health care providers was the single most important factor in influencing them to vaccinate their children.²³ Half of the men stated they would be more inclined to be vaccinated if research proved the vaccine to be helpful in men. With the absence of safety and efficacy data in men, availability of these data will be crucial to overall vaccine acceptance. Almost half of the men stated that they would be more likely to receive the vaccine if it were covered by insurance. The provision of this preventive health care measure by the insurance industry will also help successful implementation of the HPV vaccine among boys and men. In descending order of importance, men were clearly making their decision at this time based on expert opinion, research-based safety and efficacy, and financial cost. Cost, as in all medical decisions, plays a role in the decision process. We assume the cost for vaccinating men would be the same as the current expense of vaccinating women. Whether payers embrace HPV vaccination for men as readily as they have financial support for women is to be determined.

This study was limited by perhaps several underrepresented populations of men, including older men, Asians and Hispanics, men without medical insurance, and non-high school graduates. Men of certain faiths, homosexual men, and divorced men were also underrepresented. Other studies of these groups of men would be of value.

Our trial found many interesting correlates for HPV vaccination acceptance, refusal, and indecision. Men with greater general education, high-risk health behaviors, and knowledge about HPV are more likely to want the HPV vaccine. Because of the rather high rate of uncertainty among men, the availability of clinical research findings and a focused lay educational program should facilitate even wider HPV vaccine acceptance by men.