4.1. HPV Vaccine Uptake and Perceptions
Those aged 21–24 years old have the highest rate of infection with human papillomavirus than any other age group [
18]. This age group also has an increased risk of infection due to the risk associated with sexual activity. Therefore, understanding these risk factors and how HPV infection is perceived byby university students is important, as this group is the ideal target for HPV vaccination catch-up, which can occur up to 26 years of age.
Females (
p < 0.001), health-science students (
p = 0.007), those who had sex (
p = 0.019), and those who had received their COVID-19 (
p < 0.001) or annual influenza (
p < 0.001) vaccines were more likely to be vaccinated for HPV, as seen in this study. The overall uptake of the HPV vaccine was found to be 82% in the student population, which is higher than the average vaccination rates in Iowa and in similar studies of university students. In a 2022 study of HPV vaccination rates in states, Iowa had the fourth highest uptake among states, with 74.9% of adolescents aged 13–17 years having received the HPV vaccine [
19]. In a 2023 study of 417 Mid-South college students aged 18–26 years, 48.7% of students had been vaccinated for HPV, and 53% of females had received at least one dose of the vaccine [
13]. The increased rate of vaccination of students surveyed in this study may be explained by Iowa having a higher uptake of the vaccine than many other states; however, the surveyed students had a higher vaccination rate than the Iowa average as well. It is postulated that this may be due to an increase in vaccination knowledge and a push for vaccination that has been occurring in the US recently. This higher rate may also be explained by the higher number of females, as well as health-science students who responded to the survey, as it is expected that health-science students may have higher vaccination rates overall.
Female, vaccinated, and health-science students were more knowledgeable about HPV infection than other groups based on responses to HPV knowledge questions. A 2009 study showed that 93.6% of participants had heard of HPV, which is similar to the 94% found in this survey [
20]. Other studies have also shown that females know about HPV significantly more than men, which was shown in this survey [
21,
22]. This difference may be because many females will receive cervical cancer screening in their lifetime, so discussions around HPV-associated cervical cancer may happen more frequently in healthcare or personal settings for females. Vaccinated students selected HPV vaccination as the best method for HPV prevention significantly more than unvaccinated students (
p = 0.005). The correctness of response is similar to a study of students at Villanova, in which vaccinated students answered the HPV knowledge questions correctly more frequently than unvaccinated students with a near-marginal significance (
p = 0.12) [
14]. Vaccination was selected by 66% of health-science students as the best method to prevent HPV, compared to 58% of College of Liberal Arts students, and this difference was statistically significant (
p = 0.005).
In assessing the level of knowledge of HPV, the survey responses to the question “which of the following diseases does HPV not cause” showed that there may have been confusion regarding the response options given to the participants, regardless of vaccination status. With 41% of students selecting the correct answer of “breast cancer”, it can be extrapolated that 59% of students did not know that HPV was associated with some of the other listed diseases. The next most selected disease was respiratory infection at 34%. The high response rate for respiratory infection is likely explained by what the students view as respiratory infections. The survey was designed for respiratory infection to imply respiratory papillomatosis, which is a known HPV-associated disease, without explicitly stating respiratory papillomatosis. This wording could have led to confusionamong students if they viewed respiratory infection as the colloquially used definition of upper or lower respiratory infection, such as a common cold, influenza, or pneumonia. With 37% of students enrolled in a healthcare college choosing respiratory infection, it is likely that the use of “respiratory infection” caused confusion.
Understanding why individuals were not vaccinated is important in the young adult population, as increased education may increase vaccination. In those who were not vaccinated, the most common reasons as to why they were not vaccinated were parental preference, they did not know about the vaccine, or the vaccine was never offered to them. Parental preference can be addressed by educating college students at their yearly healthcare visits now that they are able to make their own decisions on healthcare. It is also important to continue to offer HPV vaccines up to age 26, which may address the knowledge gap or lack of access to the vaccine. Unvaccinated males also did not know about the vaccine, at a rate of 29% compared to 14% of unvaccinated females. Education should also be targeted toward males, as males were vaccinated later than females and were offered the vaccine at a lower rate than females. Unvaccinated males also did not know about the vaccine more frequently than unvaccinated females. With males being part of the recommended group to be vaccinated, increasing education and opportunities to become vaccinated is necessary to increase overall uptake.
Twelve percent of unvaccinated students reportedly did not receive the vaccine because they were not sexually active; however, 0% of unvaccinated students were concerned about the vaccine promoting sexual activity. This is important, as the people who are not sexually active yet are the ideal population to vaccinate for HPV. In a 2024 study by Palmer et al. in Scotland, if the HPV vaccine was given to 12–13-year-old girls prior to sexual debut, the vaccine was found to prevent cervical cancer at a rate of 100% [
23]. There was strong evidence to support the idea that vaccination rates were higher in students prior to sexual debut (
p < 0.0001) than those after sexual debut. This finding is reflected in the fact that the median age of vaccination in the student population was 14, and the average age of sexual debut was 17. University of Iowa students are being protected from HPV infection and subsequent disease by being vaccinated prior to their sexual debut. Therefore, it is necessary to increase education for those who are unvaccinated, particularly those who have not been sexually active, as these students have the greatest potential for the benefits associated with vaccination.
A secondary association found in this study was that healthcare is being used at a significantly higher rate byby those who were vaccinated compared to those who were not vaccinated. Males were more likely to have not utilized healthcare in the last year than females (
p = 0.004). A study in Brazilon HPV knowledge showed that young adult females were more likely to have visited primary care in the last year [
24]. Engaging in healthcare at a higher rate also could increase knowledge of and access to HPV vaccinations, which may explain why females were vaccinated at a higher rate than males.
It is important to note that HPV has a major impact not only in the US but worldwide. Increasing education in the US and beyond is important. Education should be targeted towards similar groups of people as found in this study, including those not having sex, males, and uneducated individuals. However, education may need to be tailored differently in other countries and should focus on targeting vaccine mistrust, addressing the costs of vaccines, and creating equitable access to vaccines [
25].
4.2. Sexual Activity in College Students
Because HPV is most frequently spread through sexual contact, it is important to understand sexual risk factors. Of the University of Iowa students, 81 out of 100 students have had sex with a median number of two lifetime sexual partners. When sex is defined as vaginal intercourse between opposite-sex partners, 40.5% of females and 38.7% of males aged 15–19 years in the US have ever had sex [
26]. When sex is defined as vaginal, oral, or anal sex, 41% of females and 39% of males aged 15–17 years and 71% of both males and females aged 18–19 years have had sex [
27]. In a 2023 student wellness survey conducted at the University of Iowa, undergraduates had an average of two sexual partners in the last 12 months, while graduate students had 1.5 [
28]. In a study of lifetime partners in secondary school adolescents, the average number of lifetime partners was 1.5 if the sexual debut was within 12 months and 4 if the sexual debut was greater than 35 months prior to the survey [
29]. A College Stats survey of current and graduated college students showed that the average number of sexual partners in collegewas 4.98 in men and 4.90 in women [
30]. This study also noted that the average number of lifetime partners for men was 14.22, and for women, it was 11.41 [
30].
The risk of HPV infection can be related to an increased number of sexual partners and having another STI. A study of women aged 35–60 years found that, for women with five or more lifetime sexual partners, the rate of high-risk HPV infection increased two-fold [
31]. Of students who have had sex, 11% have had a STI. This question was only asked to those who answered yes to having had sex. Almost one-half of the STI incidence in the US is in people aged 15 to 24 years, with 7.1 million having acquired a disease-associated HPV infection in 2018 [
32]. A University of Iowa wellness survey found that 13.5% of undergraduate and 33.4% of graduate students have been tested for HIV in their lifetime [
28]. The Iowa incidence of STIs per year is 457.2 per 100,000 people [
33].
4.3. Advantages, Limitations, and Future Studies
An advantage of completing a survey is that nearly all students had the opportunity to participate, decreasing the sampling bias. Like similar studies before, a survey was used to allow for greater access and ease of completion of the survey. An advantage of this study is that both undergraduate and graduate students were included, allowing for a larger population to be surveyed and an increased inclusion of individuals who fall into the catch-up vaccination age range and may have finished undergraduate studies.
Although the information presented in this survey discusses young adults in a university setting, the recent change in age recommendations for the HPV vaccine is an important point to consider when discussing these results. The HPV vaccine became available in 2006 in the US for females aged 9 to 26 years and was expanded to include males aged 9 to 21 years in 2011 [
34]. However, it was not until 2019 that males up to 26 years of age were recommended for catch-up vaccination. With the median age of the population surveyed being 22, most participants would fall into this recommendation; however, with the age range being 18 to 67 years, vaccination may not have been available to all who responded.
Another point to address is the demographics of those who responded to the survey do not entirely represent the same demographics of the University of Iowa student population. According to the office of Iowa registrar’s office, the spring 2024 enrollment was 29,908 with 55.1% of students identifying as female [
35]. The survey had a higher response rate for females, at 76%. A key differentiating factor is that the survey asked specifically for sex assigned at birth, while the censusreports “sex” without further definition. In comparing colleges, an expected increase in interest from those students in health-science colleges was seen. An example of this can be seen with 15% of Carver College of Medicine students responding to the survey when the medical school makes up only 3% of the student body. However, the college with the largest enrollment is the College of Liberal Arts and Sciences, with 45% of the student population, which was similar to the survey response of 44%. The number of Iowa resident students was 56.6%, which was lower than the survey response of 68%. Students identified as heterosexual at a rate of 73%, which is similar to the 2021 youth survey conducted by the CDC that found 74.2% of youth identified as heterosexual [
36].
The differences seen in the survey and university populations can likely be explained by a few factors. The firstis that the survey had a 4.9% response rate, and it may not be representative of the student body as a whole. Second, students in healthcare fields likely have more interest in the results of the study. Thus, they may have completed the survey at a higher rate. Third, as stated earlier, Iowa is the fourth most vaccinated state in the country. Therefore, Iowa students may have an increased knowledge of or interest in HPV, which may increase the response rate. Finally, the difference in male and female response rates is likely explained by HPV infections being commonly known to cause cervical cancer, which is a disease that affects females. Males can be impacted by HPV-associated disease, but they are not being screened for these diseases regularly like females are with Pap tests. In general, other surveys have also shown that females respond at an increased rate to surveys regarding HPV when compared to males [
20,
24].
Another limitationof this study is that only University of Iowa students were surveyed making these data potentially not generalizable to other institutions. This survey had a mostly female, in-state Iowa resident, Democrat, and straight (heterosexual) student response. It is likely that universities in different geographic locations outside of the Midwest may have different response rates to the questions presented in this survey.
A future research direction would be to initiate operational research studies to reach more university students, with a focus on students considered at high risk for infection and groups with the lowest vaccination rates. The high-risk groups include those who have sex with multiple partners, those who have a combination of oral, anal, and/or vaginal sex, and men who have sex with men, as testing for HPV is not common for men. The lowest vaccination rate groups include males, those who choose not to receive other vaccines, those in colleges other than health sciences, and those who are not having sex. Another group to focus educational efforts on would be the parents of adolescents, as some students reported that they were unvaccinated due to parental preference.