Single-dose HPV vaccine immunity: is there a role for non-neutralizing antibodies?

A single dose of human papillomavirus (HPV) vaccine against HPV infection (prerequisite for cervical cancer) appears to be as efficacious as two or three doses, despite inducing lower antibody titers. Neutralizing antibodies are thought to be the primary mediator of protection, but the threshold for protection is unknown. Antibody functions beyond neutralization have not been explored for HPV vaccines. Here, we discuss the immune mechanisms of HPV vaccines, with a focus on non-neutralizing antibody effector functions. In the context of single-dose HPV vaccination where antibody is limiting, we propose that non-neutralizing antibody functions may contribute to preventing HPV infection. Understanding the immunological basis of protection for single-dose HPV vaccination will provide a rationale for implementing single-dose HPV vaccine regimens.

Stories to Prevent Cancer: A Pilot Study Using Cancer Survivor Narratives to Increase Human Papillomavirus Vaccine Intentions.

INTRODUCTION: Human papillomavirus (HPV) vaccination rates are lower than other recommended adolescent vaccines. Cancer survivor narratives are used to promote cancer prevention and control, but little is known about their impact on adolescent HPV vaccination. OBJECTIVE: This pilot study explored the feasibility and effects of a video education intervention using a cancer survivor narrative to improve parents' attitudes toward and intentions to get the HPV vaccine. METHODS: This study utilized a one-group design; participants completed a pre-intervention survey, watched the video before attending their sons' wellness visits, and completed a post-intervention survey within one week of their appointment. Using the narrative persuasion framework, we developed a 4-minute video of a local HPV-related cancer survivor to promote the HPV vaccine as cancer prevention. We recruited 37 participants between June and October 2020. Participants were parents of males ages 9-17 who had not yet initiated HPV vaccination. RESULTS: After the video, more parents agreed that HPV vaccination is safe (pre: 66% vs. post: 82%; P = .045) and that their child's chances of getting HPV-related cancer in the future are high (pre: 24% vs. post: 46%; P = .014). Overall, 91% of parents felt the cancer survivor story helped them understand the risks of HPV cancers, and 52% said the story influenced their decision to start HPV vaccination for their child. CONCLUSIONS: Our findings suggest that cancer survivor narratives influence parents' vaccine opinions and understanding of their child's risk of HPV infection, leading to increased parental intent to get the HPV vaccine for their adolescent males.

Inequities in human papillomavirus vaccination among children aged 9-14 years old under constrained vaccine supply in China.

BACKGROUND: Inequities in access to human papillomavirus (HPV) vaccine are becoming a growing critical issue globally. Few studies investigate the factors determining HPV vaccine uptake disparities when vaccine supply is constrained, especially in low- and middle-income countries. The aim of this study was to investigate inequities of HPV vaccination and related factors under the constrained vaccine supply in China. METHODS: A cross-sectional survey was conducted in a developed eastern coastal province and a developing western one in China between November and December 2022. Employing multistage stratified cluster random sampling, the study collected data from parents of children aged 9-14. Mixed-effects logistic regression models with school units as random effects were used for analysis. RESULTS: From 4,127 eligible parents (as vaccine decision makers for girls), 1,346 (32.6%) intended to vaccinate their daughters against HPV, of which 836 (62.1%) attempted to schedule a vaccination appointment. Only 16.4% succeeded in booking an appointment. More than half of the intended parents expected the imported 9-valent HPV vaccine. There were significant disparities in HPV vaccine awareness, intention, and vaccination behavior across educational, income, geographic, ethnic, gender, and health literacy levels. Vaccine awareness and intentions were higher among parents with higher socioeconomic status; however, girls from lower socioeconomic families were more likely to receive the HPV vaccine and had a higher domestically produced vaccination rate. Significant disparities exist in vaccination intentions and actual vaccination behaviors, primarily due to large supply constraints of the HPV vaccine. CONCLUSIONS: Sustained health education campaigns are needed to raise awareness of the HPV vaccine, improve health literacy, and decrease over-preference for the 9-valent HPV vaccine. A mother's HPV vaccination behavior was positively associated with increased intention and actual vaccination behavior for her daughter. This study advocates for complementary cervical cancer prevention programs targeting both mothers and daughters.

Does HPV vaccination during periconceptional or gestational period increase the risk of adverse pregnancy outcomes?-An updated systematic review and meta-analysis based on timing of vaccination.

INTRODUCTION: The human papillomavirus (HPV) vaccine is crucial in preventing cervical cancer, and a significant number of women in 135 countries worldwide may have unknowingly received the vaccine during peri-pregnancy or pregnancy due to a lack of regular pregnancy testing. Previous studies on the safety of pregnancy outcomes with vaccination before and after pregnancy have not reached definitive conclusions. Thus, we subdivided the vaccination time frame and conducted an updated study to further examine whether exposure to the HPV vaccine during pregnancy or the periconceptional period increases the likelihood of adverse pregnancy outcomes. MATERIAL AND METHODS: The clinical trials and cohort studies published before August 1, 2023, were retrieved from PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials. The Newcastle-Ottawa Scale and Cochrane risk of bias assessment tool were adopted to evaluate the risk of bias in the included studies. In addition, the quality assessment was carried out using the Review Manager 5.4 Software, and a meta-analysis was conducted using the Stata 16 Software. RESULTS: Eleven studies were located. The results showed that receiving 4vHPV during the periconceptional or gestational period had no relationship with an increased risk of spontaneous abortion, stillbirth, preterm birth, birth defects, small for gestational age, and ectopic pregnancy. Neither receiving 2vHPV nor 9vHPV was associated with a higher risk of stillbirth, preterm birth, birth defects, small for gestational age, and ectopic pregnancy; however, receiving 2vHPV during the period from 45 days before last menstrual period (LMP) to LMP and 9vHPV during the period from 90 days before LMP to 45 days after LMP seemed to be related to an increased risk of spontaneous abortion (RR = 1.59, 95% CI: 1.04-2.45, RR = 2.04, 95% CI: 1.28-3.24). CONCLUSIONS: In conclusion, the likelihood of an elevated risk of spontaneous abortion caused by HPV vaccination during the periconceptional or gestational period could not be completely ruled out. Given the lack of evidence, further research is needed to examine the effect of HPV vaccination on spontaneous abortion.

Expanding vaccination competencies to community pharmacists: modelling the organizational and economic impacts of new human papilloma virus (HPV) vaccine pathways in France.

BACKGROUND: The vaccine coverage rate (VCR) for human papillomavirus (HPV) in France is one of the lowest in Europe, well below the target of 80% announced in the French Cancer Plan 2021-2030. The extension of vaccination competencies (prescription and administration) to new health care providers, such as community pharmacists (CPs), was a decisive step by the French Health Authority (HAS) in 2022 to simplify access to vaccination and improve the VCR. This research assessed the economic and organizational impacts (OIs) of the extension of vaccination competencies in France. METHODS: A model was developed in Excel® to compare the current HPV vaccination pathway focused on general practitioners (GPs) to a mix of pathways (new and current) that extends pharmacists' competencies (prescription and/or injection). The simulated population corresponded to girls and boys targeted by the French recommendations. The model was run from 2023 to 2030. HAS guidelines were used to identify OIs related to these new pathways. Model inputs were collected from national data sources and an acceptability study. The results focused on three OIs (HPV vaccination ability [defined as the number of adolescents who could be vaccinated in each pathway], the VCR projection, and flows of activity between health care professionals]). The economic impact was evaluated from the National Health Insurance (NHI) perspective in 2022. RESULTS: With a mix of vaccination pathways, including an increasing role of pharmacists, the target of an 80% VCR could be reached in 2030 (versus 2032 with the current pathway) with lower investment than the current situation, resulting in cost savings for the NHI of €212 million. Expanding vaccination competencies will provide pharmacists with additional revenue (an average of €755,000/month for all vaccinating pharmacies) and will free up medical time for GPs (average of 603,000 consultations/year for all GPs). CONCLUSIONS: Expanding vaccination competencies to pharmacists has a positive impact on the entire ecosystem. From a public health perspective, the national VCR target can be achieved and better access to care can be provided, freeing up medical time. From an economic perspective, this approach can provide savings for the NHI and additional revenue for pharmacists.

Real-world effectiveness of HPV vaccination against cervical neoplasia among birth cohorts ineligible for routine vaccination.

Human papillomavirus (HPV) vaccine effectiveness may differ between settings. Here we present the first real-world effectiveness study of HPV vaccination on high-grade cervical lesions from Norway, among women who received HPV vaccine outside the routine program. We performed an observational study of all Norwegian women born 1975 to 1996 and retrieved individual data from nationwide registries on HPV vaccination status and incidence of histologically verified high-grade cervical neoplasia during 2006 to 2016. We estimated the incidence rate ratio (IRR) and 95% confidence intervals (CI) for vaccination vs no vaccination by Poisson regression stratified by age at vaccination <20 years and ≥20 years. The cohort consisted of 832 732 women, of which 46 381 (5.6%) received at least one dose of HPV vaccine by the end of 2016. The incidence rate of cervical intraepithelial neoplasia grade 2 or worse (CIN2+) increased with age regardless of vaccination status and was highest at age 25 to 29, at 637/100 000 among unvaccinated women, 487/100 000 among women vaccinated before age 20 and 831/100 000 among women vaccinated at age 20 or older. The adjusted IRR of CIN2+ between vaccinated and unvaccinated women was 0.62 (95% CI: 0.46-0.84) for women vaccinated below age 20, and 1.22 (95% CI: 1.03-1.43) for women vaccinated at age 20 or older. These findings indicate that HPV vaccination among women too old to be eligible for routine HPV vaccination is effective among women who are vaccinated below age 20 but may not have the desired impact among women who are vaccinated at age 20 or older.

Lower human papillomavirus vaccine initiation and completion among Asian American adolescents compared to their peers: National Health and Nutritional Examination Survey 2011-2018.

PURPOSE: To compare human papillomavirus (HPV) vaccination initiation and completion between Asian American adolescents and their peers. METHODS: HPV vaccine initiation and completion of adolescents aged 9-17 years old were analyzed using the National Health and Nutritional Examination Survey data from 2011 to 2018. The outcomes were HPV vaccine initiation percentage among all adolescents and completion percentage among initiators. Odds ratios for initiation or completion among Hispanics, Blacks, and Asians (referred to as racial/ethnic minorities) versus Whites were compared using logistic regression, adjusted for adolescent's age, annual family income, parent education, and insurance coverage. RESULTS: From 2011 to 2018, overall initiation was less than 40% among U.S. adolescents. The initiation increased among boys (from 10% in 2011-12 to over 30% in 2017-2018) but not among girls. Compared to White girls, Black and Hispanic girls were more likely, while Asian girls were less likely to initiate vaccination. Although not statistically significant, Asian girls had ORs ranging from 0.65 to 0.99 for initiation compared to White girls in each of the four survey cycles. Black and Hispanic boys were more likely to initiate vaccination compared to White boys. Initiation among Asian boys increased to 39% in the 2017-2018 survey cycle. Racial/ethnic minority girls were less likely to complete the series compared to White girls, while the opposite was seen in Black boys. CONCLUSION: HPV vaccination status varies among racial/ethnic groups. Future efforts should be made to achieve the Healthy People 2020 goal of 80% vaccination among U.S. adolescents and address the gap among Asian American girls.

Spontaneous preterm birth risk among HPV-vaccinated and -unvaccinated women: a nationwide retrospective cohort study of over 240 000 singleton births.

OBJECTIVE: To determine whether prior human papillomavirus (HPV) vaccination contributes to preterm birth risk. DESIGN: Population-based retrospective cohort study. SETTING: Denmark. POPULATION: A cohort of 243 136 primiparous females born in the period 1961-2004 who had a singleton delivery at >22 weeks of gestation occurring from October 2006 to December 2018. METHODS: High-quality nationwide registries were linked to provide information on demographics, birth outcomes, HPV vaccination status, smoking, body mass index (BMI), and cervical lesions and treatment history. MAIN OUTCOME MEASURES: We assessed the association between HPV vaccination status and spontaneous preterm birth using logistic regression. To address age at vaccination, we performed a stratified analysis by vaccination before and after 17 years of age. RESULTS: In age-adjusted and fully adjusted models, there was a nonsignificant difference in the odds of spontaneous preterm birth between vaccinated and unvaccinated women (OR 1.05 (95% CI 0.99-1.12) and OR 1.04 (95% CI 0.98-1.10), respectively). There was no difference in the odds of spontaneous preterm birth in relation to time between vaccination and pregnancy. In contrast, compared with unvaccinated women, the odds of preterm birth were lower among women vaccinated before the age of 17 years (fully adjusted OR 0.87, 95% CI 0.75-1.00). This association was not present for women vaccinated at ≥17 years of age. CONCLUSIONS: In this large, population-based cohort, we found reduced odds of spontaneous preterm birth among women vaccinated against HPV at an early age compared with women who were unvaccinated. It seems conceivable that HPV vaccination may not only reduce the incidence of cervical cancer and severe precursors, but also reduce the risk of preterm birth related to HPV infection.

Sexual Behaviors and Human Papillomavirus Vaccination in a Heterosexually Active Adult Population at Increased Risk for HIV Infection.

Human papillomavirus (HPV) is the most common sexually acquired infection in the US. Vaccination is effective against infection with high-risk HPV strains, yet HPV vaccine coverage is lower in the US than the national target. This study aimed to determine the relationship between sexual behaviors and HPV vaccination in a heterosexually active population at increased risk for HIV infection. Data from 380 participants aged 18-45 years obtained from the National HIV Behavioral Surveillance system increased risk heterosexuals cycle 5 (2019) in Houston, Texas, was analyzed. RDS-Analyst was used to generate population-based descriptive statistics. Modified Poisson regression models clustered on recruitment chain were conducted in SAS 9.4 to assess the relationship between sexual behaviors and HPV vaccination. Only 11.5% of participants had received at least one dose of the HPV vaccine. Regarding behaviors within the past 12 months, 44.8% reported having condomless casual sex, 51.3% reported having concurrent sexual partnerships while in their most recent relationship, 14.5% reported exchanging sex, and participants had an average of 4-5 sex partners. Further, those who exchanged sex had a significantly lower prevalence of HPV vaccine uptake when compared to those who did not exchange sex (adjusted prevalence ratio 0.23; confidence interval 0.10-0.52), while all other measures of sexual behavior were not significantly associated with HPV vaccination. More research is needed to understand the relationship between exchange sex and low prevalence of vaccination, specifically in women who bear the highest burden of poor HPV-related morbidity and mortality.

Medical and public health professionals' perceived facilitators and barriers of human papillomavirus (HPV) vaccination among African American adolescents in Shelby County, Tennessee.

Human papillomavirus (HPV) infects nearly 85% of sexually active Americans during their lifetime, causing most cervical and five other cancers. Routine HPV vaccination is recommended for adolescents to prevent HPV-attributable cancers, but HPV vaccination coverage remains low, especially in Tennessee. In 2021, 54.6% of the population in Shelby County, Tennessee was Black or African American, reporting higher rates of new cervical cancer cases than other counties in Tennessee. While medical and public health professionals (HPs) play a critical role in promoting vaccination coverage, little is known about the factors HPs perceive to influence HPV vaccination for this population. This study sought to explore HPs' perceived facilitators and barriers of HPV vaccination among African American adolescents. Qualitative individual interviews with 26 HPs in Shelby County were conducted between October 2019 and February 2020. Interpretive content analysis of the interview data guided by the socio-ecological model revealed several important themes regarding the facilitators and barriers across the individual, interpersonal, and community levels. At the individual level, parental vaccine hesitancy emerged as a leading barrier to HPV vaccination, while appropriate education facilitated the vaccination. At the interpersonal level, a lack of strong provider recommendations impeded HPV vaccination, whereas improved communication skills with patients facilitated the vaccination. Finally, the community-level barriers included a lack of education and social/religious norms; the community-level facilitators included community outreach efforts. HPs should consider development of comprehensive community-based approaches that leverage the facilitators and barriers at multiple levels to increase HPV vaccination among African American adolescents in this region.

Disparities in awareness of the HPV vaccine and HPV-associated cancers among racial/ethnic minority populations: 2018 HINTS.

OBJECTIVES: Human papillomavirus (HPV) is a common virus that currently infects nearly 80 million people in the United States (U.S.) and can lead to cancer. HPV vaccination provides safe, effective, and lasting protection against HPV infections. Nevertheless, vaccination rates remain suboptimal. The purpose of this study was to examine the relationship between sociodemographic characteristics, HPV and HPV vaccine awareness, and knowledge of HPV-associated cancers among U.S. adults. DESIGN: Using responses from 3504 U.S. adults (aged 18 years and older) from the Health Information National Trends Survey 5 Cycle 2 (January-May 2018), we performed descriptive analysis to assess the level of awareness of HPV and HPV vaccines and knowledge of HPV-associated cancer. Multivariable regression analysis (including race, gender, age, level of education, marital status, number of children younger than 18) was conducted with weighted analysis. RESULTS: About 62% of respondents had heard of HPV and HPV vaccine. Asians had a lower level of awareness than non-Hispanic Whites of HPV (36.4% vs. 66.1%) and HPV vaccine (48.7% vs. 67.1%). Multivariable analysis showed that race/ethnicity was associated with outcomes, with Asians being less likely to have heard about HPV (aOR = 0.17, 95% CI: 0.07-0.38) and non-Hispanic Blacks (aOR = 0.57, 95% CI: 0.35-0.91) and Hispanics (aOR = 0.54, 95% CI: 0.36-0.80) being less likely to have heard of the HPV vaccine than non-Hispanic Whites. In addition, gender, age, marital status, and education were associated with awareness of HPV and the HPV vaccine; in particular, individuals who were female, younger (18-45), married, and more highly educated were more likely to have heard of HPV and HPV vaccine. CONCLUSION: Results highlight disparities in HPV and HPV vaccine awareness among racial/ethnic minority populations. Future interventions and legislation should target racial/ethnic minority populations to foster improvements in HPV vaccine uptake and reduce disparities in HPV-associated cancers.

The Evaluation of a Digital Health Intervention to Improve Human Papillomavirus Vaccine Recommendation Practices of Medical Students.

We investigated what is being taught about HPV in US medical schools and evaluated a digital health intervention for medical students to increase their intention to provide a high-quality HPV vaccine recommendation. An online survey was emailed to Academic Deans at the 124 accredited US Schools of Medicine and Osteopathic Medicine between February and April 2018. A digital educational module was emailed to medical students in June 2020. A single-subject longitudinal study design was employed. Pre- post-survey administration measured change in knowledge, attitudes, subjective norms, perceived behavioral control, and intention to recommend HPV vaccine. Gaps in medical school curricula were found. Very few schools (~ 9%) reported teaching content on HPV prevention strategies or patient education. For the digital intervention, independent and dependent variables increased positively. Perceived behavioral control improved at significant levels as participants felt more confident addressing parents' concerns about the vaccine (p < 0.001) and more confident recommending the vaccine for patients (p < 0.05) post module. On the pre-survey, only 6% of the sample knew the most effective HPV vaccine communication style and on the post-survey 81% correctly identified it (p < 0.001). The intervention increased HPV and HPV vaccine knowledge, self-efficacy, and intention to provide a high-quality HPV vaccine recommendation to patients.

An Interactive Educational Tool to Improve Human Papillomavirus Vaccine Knowledge and Recommendation Among Nurses.

In United States, only 57% of  women and 53% of men in the recommended age groups have received all recommended doses of the human papillomavirus (HPV) vaccine. Healthcare provider education has been associated with strong vaccine recommendation and vaccination uptake. Our objective was to create a 7-min interactive online educational tool to improve knowledge and willingness to recommend the HPV vaccine among nurses. This is a prospective pre-test/post-test study to evaluate the effectiveness of the educational tool consisting of 10 flashcards in a question-answer format. Oncology nurses at our cancer center were invited to participate by email, which led them to the educational tool (i.e., intervention) along with pre- and post-test questions on HPV-associated cancers, vaccine-eligible age groups, dosing schedules, adverse events, and willingness to recommend. Of the 110 participants (mean age of 41.2 ± 11.4, 98% female, 64% >10 years of practice), there was improvement in knowledge after intervention in HPV-associated cancers (81% to 97%; p = 0.02), percentage of cervical caused by HPV (33% to 64%; p < 0.05), and dosing schedule (47% to 93%; p < 0.05). All participants correctly stated that continued screening is needed after vaccination both pre- and post-intervention. Eighty-five percent strongly agreed that the intervention improved their HPV knowledge, and 77% stated they were more likely to recommend the HPV vaccine after the intervention. While nurses are willing to recommend the vaccine, there remains persistent knowledge gaps. A brief 7-min self-administered online interactive flashcard educational intervention is effective in improving the HPV vaccine knowledge among nurses.

Associations Between Human Papillomavirus Vaccine Decisions and Exposure to Vaccine Information in Social Media.

PURPOSE: Exposure to different types of vaccine information in social media can result in parents making disparate vaccine decisions, including not following national guidelines for human papillomavirus (HPV) vaccination. We sought to characterize parents' exposure to and engagement with information about HPV vaccination in social media, and the associations between exposure to such information and vaccine decisions for their adolescent children. METHODS: In 2019, we conducted a web-based survey with a national sample of 1073 parents of adolescents who use social media. The survey assessed whether parents have seen information in favor, against, or mixed about HPV vaccination. Multivariable logistic regressions assessed correlates of vaccine decisions, including HPV vaccine initiation, delay, and refusal. RESULTS: Sixty-one percent of parents reported that their children have initiated HPV vaccination. Over one-third of parents (37%) reported seeing HPV vaccine information on social media, which was either in favor (20%), against (5%), or a mix (12%). Parents exposed to information in favor were more likely than those who saw no information to have initiated HPV vaccination (OR = 1.74, 95% CI:1.24, 2.44). Parents exposed to information against vaccination were more likely to have delayed (OR = 3.29, 95% CI:1.66, 6.51) or refused (OR = 4.72, 95% CI:2.35, 9.50) HPV vaccination. Exposure to mixed information was also significantly associated with vaccine delay and refusal. DISCUSSION: Our findings suggest that the type of information seen on social media regarding HPV vaccination may influence the decisions parents make about vaccinating their children. Efforts should be sought to increase online information in favor of HPV vaccination and combat vaccine misinformation in social media.

Impact assessment of a provider-targeted national vaccine messaging campaign on human papillomavirus vaccination rates among US adolescent males.

Initial uptake of the cancer-preventative human papillomavirus (HPV) vaccine in the US was slow, especially among adolescent males. To address this, the US Centers for Disease Control and Prevention (CDC) partnered with the Hager Sharp communications development company to launch a national campaign in 2015 to improve physician counseling and rebrand the vaccine as cancer prevention. In this study, we compared HPV vaccination rates among 13-17-year-old males before (2010-2014) and after (2015-2019) the CDC-Hager Sharp campaign using National Immunization Survey-Teen data to determine the potential impact of this campaign on improving vaccine uptake among adolescent males. Employing provider-verified vaccination data available for 49,644 males from 2010 to 2014 and 47,943 males from 2015 to 2019, we found that the adjusted prevalence ratios of 13-17-year-old males who initiated and completed the vaccine series increased approximately 5-fold between the 2010-2014 and 2015-2019 periods. Increases in post-campaign initiation/completion rates were greatest among respondents with mothers who were married or had attended college, respondents who lived in the Northeast or Midwest, and those from households with annual incomes > $75,000. Together, these data suggest that the campaign contributed to the observed increase in HPV vaccine uptake among adolescent males. Although sociodemographic disparities were identified, the greater improvement in vaccination rates observed among individuals with higher socio-demographic status may simply reflect their relatively poorer rates of initial vaccine uptake. Overall, the data suggest that provider-targeted campaigns can be a useful tool to boost vaccinations and should be considered for inclusion in future vaccination campaigns.

A Nationwide Epidemiological Survey of Adolescent Patients With Diverse Symptoms Similar to Those Following Human Papillomavirus Vaccination: Background Prevalence and Incidence for Considering Vaccine Safety in Japan.

BACKGROUND: Since June 2013, Japan has suspended proactive recommendation of human papillomavirus (HPV) vaccination due to self-reported diverse symptoms, including pain and motor dysfunction, as possible serious adverse events following immunization. Although these symptoms may be seen in adolescents without HPV vaccination, their frequency, taking into account disease severity, has not been examined. METHODS: A two-stage, descriptive, nationwide epidemiological survey was conducted in 2016, with a 6-month target period from July 1 to December 31, 2015, to estimate the prevalence and incidence of diverse symptoms among Japanese adolescents without HPV vaccination. Participants were 11,037 medical departments in hospitals selected nationwide by stratified random sampling. Eligible patients had to satisfy four criteria: (1) aged 12-18 years upon visiting hospital; (2) having at least one of four symptoms/disorders (pain or sensory dysfunction, motor dysfunction, autonomic dysfunction, or cognitive impairment); (3) symptoms/disorders persisting for at least 3 months; and (4) both criteria (2) and (3) influence attendance at school or work. We then extracted data of patients with diverse symptoms similar to those after HPV vaccination while considering opinions of doctors in charge. RESULTS: Estimated 6-month period prevalence of diverse symptoms among girls aged 12-18 years without HPV vaccination was 20.2 per 100,000. Annual incidence was estimated to be 7.3 per 100,000. CONCLUSION: Adolescent Japanese girls without HPV vaccination also visited hospitals with diverse symptoms similar to those following HPV vaccination. Our findings predict the medical demands for coincident diverse symptoms, which are temporally associated with but not caused by HPV vaccination of Japanese adolescents.

Human papillomavirus vaccination at the national and provincial levels in China: a cost-effectiveness analysis using the PRIME model.

BACKGROUND: Human papillomavirus (HPV) vaccines have been proven effective against cervical cancer. However, HPV vaccination is not included in the Chinese immunization program. This study aimed to assess the cost-effectiveness of incorporating different HPV vaccines into immunization programs at the Chinese national and provincial levels. METHODS: The Papillomavirus Rapid Interface for Modeling and Economics model was used to estimate the possible cost and social and economic benefits of adopting various HPV vaccination immunization strategies in 31 provinces in Mainland China in 2019. Demographic and regional economic data were obtained from the national and provincial Statistical Yearbook. The cost of vaccines was gathered from the centralized procurement information platform of all Chinese provinces. Treatment costs, epidemiological data, and other model parameters were obtained from published literature. The cost of vaccination, treatment costs saved, net costs, cases and deaths averted, life years saved, disability-adjusted life years (DALYs) prevented, and incremental cost-effectiveness ratios were predicted both provincially and nationally. Deterministic sensitivity analyses were used to explore model uncertainty. RESULTS: The net cost of vaccinating with the domestic bivalent HPV vaccine was the lowest. At the national level, after bivalent or quadrivalent HPV vaccination, the number of cases and deaths averted due to cervical cancer were 12,545 and 5109, respectively, whereas the 9-valent HPV vaccine averted 28,140 cases and 11,459 deaths. HPV vaccines were cost-effective at a national level (maximum cost US$ 18,165 per DALY gained.) compared to the 3 times GDP per capita (US$ 30,837). Bivalent HPV vaccines were cost-effective in all 31 provinces. Imported quadrivalent and 9-valent HPV vaccines were cost-effective in 29 provinces, except Heilongjiang and Gansu. The univariate sensitivity analysis showed that the results were robust when the model parameters were changed, and that the discount rate was the main factor affecting the baseline results. CONCLUSIONS: This study provides evidence that the inclusion of HPV vaccination in the immunization program would be cost-effective at a national level and in most provinces. Provinces with a higher population have more prevented cases, deaths, and DALYs. The economics of HPV vaccination at the provincial level differs from that at the national level, and provinces with an inability to pay should seek help from state subsidies.

Facilitators and barriers of healthcare workers' recommendation of HPV vaccine for adolescents in Nigeria: views through the lens of theoretical domains framework.

BACKGROUND: The human Papillomavirus (HPV) vaccine has demonstrated efficacy in the prevention of cervical cancer when given in early adolescence. The recommendation of the vaccine by health care workers (HCW) is crucial to the uptake of the vaccine by adolescents and the process of this recommendation is important as it determines subsequent uptake of the vaccine. Understanding of the facilitators and barriers of recommendation of this vaccine can help in the development of strategies to improve its recommendation rates and uptake. This study therefore explored the facilitators and barriers for the recommendation of HPV vaccine for adolescents by HCW in Ibadan, Nigeria using the Theoretical Domain Framework (TDF). METHODS: Key informant interviews were conducted with 14 purposively selected HCW who were in charge of vaccination. Content analysis was used after deductive coding of the data using the domains of the TDF. Relevant concepts for facilitators and barriers of HPV vaccine recommendation and quotes were then identified. RESULTS: Mean age of the HCW was 47.7 ± 6.5 years and they consisted of eight nurses, four medical doctors, one medical social worker and one health visitor. Ten domains of the TDF were represented among the facilitators and barriers against the recommendation of HPV vaccination by the HCW, except the goals; memory, attention, decision process; emotion; and behavioral regulation domains. The domains with the highest frequency of concepts were: knowledge, skills, social/professional role and identity, beliefs about capabilities, beliefs about consequences, intention and environmental context and resources. Domains with conflicting statements in the concept were: environmental context and resources, and beliefs about consequences. While those with perceived strength of concept were: social influences, reinforcement and optimism. CONCLUSION: All the 10 identified domains of the TDF are potential areas of focus for strategies for improving the recommendation of HPV vaccine for adolescents by health care workers in Nigeria and other countries with similar sociocultural settings.

Willingness to pay for HPV vaccine among female health care workers in a Chinese nationwide survey.

BACKGROUND: Payment methods for human papillomavirus (HPV) vaccine could substantially influence vaccination behavior. In China, HPV vaccination uptake remains currently low. This study aims to determine willingness to pay (WTP) for HPV vaccines among Chinese female health care workers under different payment scenarios. METHODS: This is a nationwide online survey recruiting female health care workers aged 18-45 years from 31 provinces throughout China. We collected the respondents' vaccination status of HPV vaccines and their sociodemographics. Two WTPs were defined and estimated in the study. A general WTP for HPV vaccination was determined using the contingent valuation method with double dichotomous choice bidding. A WTP out-of-pocket was estimated for each HPV vaccine under two scenarios, including partial coverage by governmental subsidy or partial incorporation in basic medical insurance. Accordingly, a multivariable linear regression model was employed to determine the association between sociodemographis and general WTP. Then the maximum WTP out-of-pocket was compared among the respondents' attitude shift towards HPV vaccination, payment scenarios, and levels of vaccine attributes, using non-parametric Kruskal-Wallis test. RESULTS: A total of 15,969 respondents were included in the study. The median general WTP was 2000 CNY (interquartile range, 1000-3200 CNY), positively associated with younger age, unmarried status, higher monthly income, fewer children, more positive vaccination behavior, working in tertiary hospital, higher local GDP and HDI (each P < 0.05). Moreover, the median WTP out-of-pocket was 1250 CNY (540-2000 CNY). It was significantly higher for vaccines partly covered by governmental subsidy (median, 1250 CNY; interquartile range, 560-2000 CNY), imported vaccines (1260 CNY; 630-1960 CNY), and 9-valent vaccines (1400 CNY; 750-2240 CNY) (each P < 0.001). Additionally, majority of respondents did not change their attitude towards HPV vaccination between two payment scenarios; those remaining with more expensive HPV vaccines (51.1%) had higher WTP out-of-pocket (1400 CNY; 560-2250 CNY) than those with cheaper vaccines (39.0%) (1120 CNY; 490-1960 CNY) (P < 0.001). CONCLUSION: Chinese female health care workers have high WTP for HPV vaccines. A direct public funding for HPV vaccination is more preferable. Our findings may facilitate the adjustment of HPV vaccination strategy and payment mechanism in China.

Knowledge and willingness of parents towards child girl HPV vaccination in Debre Tabor Town, Ethiopia: a community-based cross-sectional study.

BACKGROUND: Cervical cancer is currently the second-leading cause of cancer death among women in Ethiopia. Vaccination against the human papillomavirus (HPV) is an effective primary prevention strategy for HPV-related illnesses. The knowledge and willingness of parents toward the HPV vaccine are crucial to increasing the uptake of the vaccine. The vaccine's acceptance by children and young adolescents is dependent on parental consent. Therefore, this study aimed to assess knowledge, willingness, and associated factors of the human papillomavirus vaccine among parents of girls aged 9-14 years at Debre Tabor Town. METHOD: A community-based cross-sectional study was conducted among participants from December 10, 2020, to January 15, 2021. A simple random sample technique was used to include 638 participants. A structured face-to-face interviewer-administered questionnaire was used to collect data. The data were entered and analyzed using Epi-Data and SPSS software, respectively. Bivariate and multivariable analyses were used to examine the association. The Odds Ratio (OR), 95% CI, and p-values less than 0.05 were used to determine the statistical association. RESULTS: Thirty-five percent (35.4%, 95% CI = 31.4%, 38.8%) and 44.8% (95% CI = 40.40%, 48.67%) of participants were knowledgeable about HPV vaccination and willing to get it, respectively. Being government employees (AOR = 5.46, 95% CI = 2.42, 9.34), and having a family history of sexually transmitted diseases (STD) (AOR = 1.76, 95% CI = 1.14, 2.72) were significantly associated with knowledge of the human papilloma virus (HPV) vaccine. Participants' age (AOR = 1.43, 95% CI = 1.16, 2.87), secondary education and above (AOR = 1.70, 95% CI = 1.05, 2.74), fear of HPV infection (AOR = 2.29, 95% CI = 1.21, 4.32), and having good knowledge of the HPV vaccine (AOR = 3.30, 95% CI = 2.21, 4.93) were significantly associated with willingness to receive the HPV vaccine. CONCLUSION AND RECOMMENDATION: The knowledge and willingness of parents toward the HPV vaccine were low. Then, health officials should boost HPV vaccination promotion through public media. In schools, churches, mosques, and health facilities, health extension workers and health professionals provide information about the HPV vaccine for the parents. Mixed quantitative and qualitative studies are preferable for future research to address "why" issues.

Infection with the Human Papillomavirus (HPV) causes nearly 99% of cervical cancer cases and more than 20% of breast, neck, and anogenital cancers. The HPV vaccines protect against high-risk types of HPV (types 16 and 18), which account for approximately 70% of cervical cancers. Global coverage of the HPV vaccine was 39.7%, with high-income countries (68%), middle-income countries (28%), and lower-middle-income countries (2.7%). For different reasons, cervical cancer screening is very poor in Ethiopia (below 2%). Cervical cancer is mostly asymptomatic more than 20 years after infection. Primary prevention (enhancing the HPV vaccine) is the best way to protect women from cervical cancer. Adolescents' uptake and acceptance of the vaccine depend on parental consent. Assessing parental knowledge and willingness at a community level is very crucial.A simple random sample technique was used to include 638 participants. A structured and pre-tested face-to-face interviewer-administered questionnaire was used to collect the data. The data were entered and analyzed using Epi-Data, and SPSS software, respectively. Bivariate and multivariable analyses were used to examine the association.Nearly one-third (35.4%) and less than half (44.8%) of participants were knowledgeable and willing to receive the HPV vaccination. The knowledge and willingness of the parents are significantly lower. Being government employees and having a family history of sexually transmitted diseases (STD) were factors affecting the knowledge of parents about the human papillomavirus vaccine. Participants' age, secondary education and above, fear of HPV infection, and having good knowledge of the HPV vaccine were significantly associated with their willingness to use the HPV vaccine. The knowledge and willingness of the parents are significantly lower. Health officials and stakeholders should scale up HPV vaccine promotion through public media.