Effectiveness and Cost-Effectiveness of Human Papillomavirus Vaccination Through Age 45 Years in the United States

HPV vaccines - A game changer for preventing HPV-related cancers

INTRODUCTION

Human papillomaviruses (HPV) cause almost all cervical cancer cases globally, with the high-risk genotypes 16/18 causing at least 70 % of cancers, of which most cases occur in low-to-middle-income countries. Prophylactic vaccination plays a major role in the prevention of cervical cancer, which could effectively prevent the incidence of HPV infection. The L1 protein, which, when assembled into virus-like particles, induces HPV-type-specific neutralizing antibodies, which form the basis of all currently licensed HPV vaccines. There are six approved prophylactic HPV vaccines. All these vaccines are designed to prevent HPV 16 and 18-associated cervical precancers, thereby preventing approximately 70 % of the cancers. This review looks at the current HPV prophylactic vaccines, their mechanism of action, vaccination schedules, and the cost of different vaccines.

Utilization and outcomes of serial cervical cancer screening in a National Breast and Cervical Cancer Early Detection Program (NBCCEDP) in a non-Medicaid expansion state

PURPOSE

Since 1990, the Centers for Disease Control and Prevention's National Breast and Cervical Cancer Early Detection Program (NBCCEDP) has offered free cervical cancer screening to low-income, uninsured patients, increasing single time point screening and early detection rates. Little is known about NBCCEDP's longitudinal effectiveness. The objective of this study was to assess utilization of Kansas's NBCCEDP, early detection works (EDW) for one-time versus serial screening and compare rates of cervical dysplasia between groups.

METHODS

A retrospective cohort study was conducted among patients who received cervical cancer screening through EDW from 2001 to 2021. Demographic factors, Papanicolaou (Pap) test, and human papillomavirus (HPV) results were compared between patients with one screening versus multiple. Descriptive statistics were performed.

RESULTS

From 2014 to 2021, 3.71-7.06% of eligible patients completed screening through EDW annually. 17.4% of 58,582 eligible patients were up-to-date with screening in 2020. Rural patients and those under age forty were less likely to have EDW screening. Of 43,916 ever-screened patients, 14,638 (33.3%) received multiple screenings. 77% of patients did not have HPV testing; rates were lower in serially screened patients. Cervical dysplasia rates differed minimally between groups.

CONCLUSION

Despite screening 24,017 patients over 7 years, EDW maintains up-to-date screening for under one-fourth of eligible Kansans. Young and rural patients less frequently access EDW. HPV testing is underutilized, which limits the negative predictive value of screening. Serial screening is largely used by low-risk patients currently. Identification and prioritization of serial screening in high risk could increase program impact.

Improving HPV Vaccine Coverage in Tennessee: Addressing Barriers and Expanding Access for Mid-Adults

Human papillomavirus (HPV) is the most common sexually transmitted infection in the US and the world. Infection with high-risk oncogenic HPV strains has been shown to induce cellular transformation leading to anogenital and oropharyngeal cancers. The HPV vaccine, first developed in 2006 for females aged 9-26 years, has been demonstrated to be safe and effective in preventing 90% of all HPV-associated cancers. However, vaccine hesitancy, misinformation, and barriers to vaccine access has resulted in suboptimal vaccination rates among adolescent populations, especially in rural communities in the South. HPV vaccine coverage in Tennessee is currently below the national average and below the Healthy People 2030 goal of an 80% vaccination rate for individuals 13-17 years old based on recommendation guidelines for up-to-date HPV vaccination status as of 2022. HPV vaccination rates for Tennesseans with private insurance in 2022 were 68% and 38% for those that were uninsured. Up-to-date HPV vaccination rates in 2022 for Tennesseans were 58% and 46% for those living in urban communities and rural communities, respectively. Overall, HPV-associated cancers rates are higher in Tennessee, at 12.9/100,000 compared to the overall rate in the US of 11.8/100,000 persons in 2022. Interventions to improve HPV vaccine awareness, education, and access could improve vaccine confidence and uptake, especially among rural and uninsured populations in Tennessee. Most recently, the Advisory Committee on Immunization Practices (ACIP) expanded recommendations for HPV vaccinations for some individuals aged 27-45 years who were not vaccinated at a younger age, with shared clinical decision making. Further research is needed to evaluate the impact of this recommendation on HPV vaccination rates and cancer prevention in Tennessee.

[Human papillomavirus and systemic lupus erythematosus: A systematic review]

BACKGROUND

Human papillomavirus (HPV) infections cause cancer of the cervix, vagina, vulva, anus, penis and upper respiratory tract. The prevention of HPV-induced cancers is a public health issue. Patients with systemic lupus are at increased risk of persistent HPV infection and cervical cancer due to treatment-induced immunosuppression. HPV vaccination and screening for precancerous lesions are two effective means of preventing cervical cancer. Despite the demonstrated safety and efficacy of the HPV vaccine, coverage of HPV vaccination in SLE adults remains low. Screening for cervical cancer is only carried out as recommended in one lupus patient in two. Catch-up HPV vaccination, therapeutic vaccination and vaginal self-sampling are innovative prevention strategies adapted to patients at risk of HPV-induced cancer.

CONCLUSIONS

Measures to prevent HPV-induced cancers are insufficiently implemented in patients managed for systemic lupus. Healthcare professionals and patients need to be made aware of the importance of HPV preventing vaccination.

Modelling epidemiological and economics processes - the case of cervical cancer

Different types of mathematical models can be used to forecast the development of diseases as well as associated costs and analyse the cost-effectiveness of interventions. The set of models available to assess these parameters, reach from simple independent equations to highly complex agent-based simulations. For many diseases, it is simple to distinguish between infectious diseases and chronic-degenerative diseases. For infectious diseases, dynamic models are most appropriate because they allow for feedback from the number of infected to the number of new infections, while for the latter Markov models are more appropriate since this feedback is not required. However, for some diseases, the aforementioned distinction is not as clear. Cervical cancer, for instance, is caused by a sexually transmitted virus, and therefore falls under the definition of an infectious disease. However, once infected, the condition can progress to a chronic disease. Consequently, cervical cancer could be considered an infectious or a chronic-degenerative disease, depending on the stage of infection. In this paper, we will analyse the applicability of different mathematical models for epidemiological and economic processes focusing on cervical cancer. For this purpose, we will present the basic structure of different models. We will then conduct a literature analysis of the mathematical models used to predict the spread of cervical cancer. Based on these findings we will draw conclusions about which models can be used for which purpose and which disease. We conclude that each type of model has its advantages and disadvantages, but the choice of model type often seems arbitrary. In the case of cervical cancer, homogenous Markov models seem appropriate if a cohort of newly infected is followed for a shorter period, for instance, to assess the impact of screening programs. For long-term consequences, such as the impact of a vaccination program, a feedback loop from former infections to the future likelihood of infections is required. This can be done using system dynamics or inhomogeneous Markov models. Discrete event or agent-based simulations can be used in the case of cervical cancer when small cohorts or specific characteristics of individuals are required. However, these models require more effort than Markov or System Dynamics models.

Roles of human papillomavirus in cancers: oncogenic mechanisms and clinical use

Human papillomaviruses, particularly high-risk human papillomaviruses, have been universally considered to be associated with the oncogenesis and progression of various cancers. The genome of human papillomaviruses is circular, double-stranded DNA that encodes early and late proteins. Each of the proteins is of crucial significance in infecting the epithelium of host cells persistently and supporting viral genome integrating into host cells. Notably, E6 and E7 proteins, classified as oncoproteins, trigger the incidence of cancers by fostering cell proliferation, hindering apoptosis, evading immune surveillance, promoting cell invasion, and disrupting the balance of cellular metabolism. Therefore, targeting human papillomaviruses and decoding molecular mechanisms by which human papillomaviruses drive carcinogenesis are of great necessity to better treat human papillomaviruses-related cancers. Human papillomaviruses have been applied clinically to different facets of human papillomavirus-related cancers, including prevention, screening, diagnosis, treatment, and prognosis. Several types of prophylactic vaccines have been publicly utilized worldwide and have greatly decreased the occurrence of human papillomavirus-related cancers, which have benefited numerous people. Although various therapeutic vaccines have been developed and tested clinically, none of them have been officially approved to date. Enhancing the efficacy of vaccines and searching for innovative technologies targeting human papillomaviruses remain critical challenges that warrant continuous research and attention in the future.

Cervical cancer screening by cotesting method for Vietnamese women 25-55 years old: a cost-effectiveness analysis

BACKGROUND

Cervical cancer (CC) is preventable through regular screening and vaccination against human papillomavirus (HPV). However, CC remains a significant public health issue in low-income and middle-income countries (LMICs) like Vietnam, where financial constraints hinder the widespread implementation of HPV vaccination and screening programmes. Currently, Vietnam lacks both a national CC screening intervention and an HPV vaccination programme for women and girls. To date, cost-effectiveness studies evaluating CC screening methods in Vietnam remain limited.

OBJECTIVES

To evaluate the cost-effectiveness of two CC screening strategies for Vietnamese women aged 25-55 years: (1) cotesting combining cytology and HPV testing conducted three times at 5 year intervals (intervention) and (2) cytology-based screening conducted five times at 2 year intervals (comparator). The objective is to provide evidence to inform policy and clinical practice in Vietnam.

DESIGN

Cost-effectiveness analysis using a Markov model with 1 year cycles to simulate the natural progression of CC.

SETTING

The Vietnamese healthcare system, modelled from the provider's perspective, with parameters adapted to the local context through expert consultations.

PARTICIPANTS

A simulated cohort of Vietnamese women aged 25-55 years.

INTERVENTIONS

The intervention involved cotesting (cytology and HPV testing) three times at 5 year intervals. The comparator was cytology-based screening conducted five times at 2 year intervals.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome measure was quality-adjusted life years (QALYs). Costs and cost-effectiveness ratios were assessed using Vietnam's gross domestic product (GDP) per capita as the cost-effectiveness threshold (1-3 times GDP per capita). Sensitivity analyses (one-way deterministic and probabilistic) were conducted to account for uncertainties.

RESULTS

The cotesting strategy was less effective and more costly than cytology-based screening across all age groups. Cotesting resulted in higher costs and fewer QALYs than the comparator. Probabilistic sensitivity analyses confirmed that cotesting was not cost-effective under current conditions in Vietnam.

CONCLUSIONS

Cytology-based screening conducted five times at 2 year intervals is a more cost-effective option for CC screening in Vietnamese women aged 25-55 years. The cotesting strategy cannot be recommended due to its higher cost and lower effectiveness.

Cost-Effectiveness of Extending Human Papillomavirus Vaccination to Population Subgroups Older Than 26 Years Who Are at Higher Risk for Human Papillomavirus Infection in the United States

BACKGROUND

In June 2019, the U.S. Advisory Committee on Immunization Practices recommended shared clinical decision making regarding potential human papillomavirus (HPV) vaccination of men and women aged 27 to 45 years ("mid-adults").

OBJECTIVE

To examine the incremental cost-effectiveness ratios (ICERs) and number needed to vaccinate (NNV) to prevent 1 HPV-related cancer case of expanding HPV vaccination to subgroups of mid-adults at increased risk for HPV-related diseases in the United States.

DESIGN

Individual-based transmission dynamic modeling of HPV transmission and associated diseases using HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation).

DATA SOURCES

Published data.

TARGET POPULATION

All U.S. mid-adults and higher-risk subgroups within this population.

TIME HORIZON

100 years.

PERSPECTIVE

Health care sector.

INTERVENTION

Expanding 9-valent HPV vaccination to mid-adults and higher-risk subgroups.

OUTCOME MEASURES

ICERs and NNVs.

RESULTS OF BASE-CASE ANALYSIS

Expanding 9-valent HPV vaccination to all mid-adults, those with more lifetime partners, and those who have just separated was projected to cost an additional $2 005 000, $763 000, and $1 164 000 per quality-adjusted life-year (QALY) gained, respectively. The NNVs to prevent 1 additional HPV-related cancer case were 7670, 3190, and 5150, respectively, compared with 223 for vaccination of persons aged 9 to 26 years (vs. no vaccination).

RESULTS OF SENSITIVITY ANALYSIS

The mid-adult strategy with the lowest ICER and NNV was vaccinating infrequently screened mid-adult women who have just separated and have a higher number of lifetime sex partners (ICER, $86 000 per QALY gained; NNV, 470).

LIMITATION

Uncertainty about rate of new sex partners and natural history of HPV among mid-adults.

CONCLUSION

Vaccination of mid-adults against HPV is substantially less cost-effective and produces higher NNVs than vaccination of persons younger than 26 years under all scenarios investigated. However, cost-effectiveness and NNV are projected to improve when higher-risk mid-adult subgroups are vaccinated, such as mid-adults with more sex partners and who have recently separated, and women who are underscreened.

PRIMARY FUNDING SOURCE

Centers for Disease Control and Prevention.

Factors associated with HPV vaccine hesitancy among college students: A cross-sectional survey based on 3Cs and structural equation model in China

Despite the high effectiveness of HPV vaccines in preventing infection, vaccine hesitancy remains a concern, particularly in China. This study aimed to explore college students' attitudes toward HPV vaccination and identify associated factors. Data was collected through a cross-sectional survey using self-administered questionnaires in four cities from May to June 2022. Chi-square tests and logistic regression analyses were conducted to identify factors. Additionally, an integrated structural equation model (SEM) based on the 3Cs (confidence, convenience, complacency) was developed to understand underlying factors contributing to hesitancy. The results from 2261 valid questionnaires were enlightening. A significant 89.47% (59.4% for females) considered HPV vaccination necessary, with 9.82% remaining neutral and only 0.71% deeming it unnecessary. Factors like higher education, being a medical student, residing in urban areas, having medical insurance, more extraordinary living expenses, a family history of tumors, and a solid understanding of HPV played a role in perceiving the vaccine as necessary. Among the 1438 female respondents, 84.36% had no hesitancy toward HPV vaccination, 13.53% expressed hesitancy, and 2.11% refused vaccination. Factors like age, understanding of HPV, medical staff recommendations, living expenses, and family history influenced hesitancy levels. SEM revealed that the 3Cs significantly affected vaccine hesitancy. Factors like price, booking process, vaccination times, trust in vaccines, medical staff recommendations, efficiency, and risk perception collectively influenced hesitancy. In conclusion, this study found high acceptance of HPV vaccination but acknowledged the complexity of hesitancy factors. It recommends medical staff disseminate scientific knowledge, offer recommendations, simplify booking procedures, and expand vaccination sites to address vaccine hesitancy effectively.

Population-level impact of switching to 1-dose human papillomavirus vaccination in high-income countries: examining uncertainties using mathematical modeling

BACKGROUND

A concern in high-income countries is that switching to 1-dose human papillomavirus (HPV) vaccination could cause a rebound in HPV infection and cervical cancer if 1-dose efficacy or duration were inferior to 2 doses. Using mathematical modeling and up-to-date trial-based data, we projected the population-level effectiveness of switching from 2-dose to 1-dose vaccination under different vaccine efficacy and duration assumptions in high-income countries.

METHODS

We used HPV-ADVISE (Agent-based Dynamic model for VaccInation and Screening Evaluation), a transmission-dynamic model of HPV infection and cervical cancer, varying key model assumptions to identify those with the greatest impact on projections of HPV-16 and cervical cancer incidence over time: 1) 1-dose vaccine efficacy and vaccine duration, 2) mechanisms of vaccine efficacy and duration over time, 3) midadult (>30 years of age) sexual behavior, 4) progression to cervical cancer among midadults, and 5) vaccination coverage and programs.

RESULTS

In high-income countries, 1-dose vaccination would cause no appreciable rebound in HPV-16 infection, except for a limited rebound under the most pessimistic assumptions of vaccine duration (average, 25 years), because 1) the switch would occur when HPV prevalence is low because of high 2-dose vaccination coverage and 2) individuals would be protected during their peak ages of sexual activity (<35 to 40 years of age). Our model projects a more limited rebound in cervical cancer because of a shift to older age at infection, resulting in fewer life-years left to potentially develop cancer. Projections were robust when varying key model assumptions.

CONCLUSIONS

High protection during peak ages of sexual activity in high-income countries would likely mitigate any potential rebounds in HPV infection and cervical cancer under the most pessimistic assumptions of 1-dose efficacy and duration.

Switching from a 2-dose to a 1-dose program of gender-neutral routine vaccination against human papillomavirus in Canada: a mathematical modelling analysis

BACKGROUND

Worldwide, countries are examining whether to implement 1-dose human papillomavirus (HPV) vaccination instead of using 2 doses. To inform policy, we sought to project the population-level impact and efficiency of switching from 2-dose to 1-dose gender-neutral routine HPV vaccination in Canada.

METHODS

We used HPV-ADVISE, an individual-based transmission-dynamic model of HPV infections and diseases, to mathematically model vaccination programs in 2 provinces, Quebec, a province with high HPV vaccination coverage (around 85%), and Ontario, which has lower coverage (around 65%). We examined non-inferior and pessimistic scenarios of the efficacy (vaccine efficacy of 98% or 90%) and average vaccine duration (lifelong, 30 yr, or 25 yr) of 1 dose compared with 2 doses (98% vaccine efficacy, lifelong vaccine duration). Our main outcomes were the relative reduction in HPV-16 (by sex) and cervical cancers, and the number of doses needed to prevent 1 cervical cancer.

RESULTS

Our model projected that 1-dose HPV vaccination would avert a similar number of cervical cancers as 2 doses in Canada, under various scenarios. Under the most pessimistic scenario (25-yr vaccine duration), 1-dose vaccination would avert fewer cervical cancers than 2 doses, by about 3 percentage points over 100 years. All 1-dose scenarios were projected to lead to elimination of cervical cancer (< 4 cervical cancers/100 000 female-years) and to be a substantially more efficient use of vaccine doses than a 2-dose scenario (1-dose v. no vaccination = 800-1000 doses needed to prevent 1 cervical cancer; incremental doses for 2-dose v. 1-dose vaccination > 10 000 doses needed to prevent 1 additional cervical cancer).

INTERPRETATION

If the average duration of 1-dose protection is longer than 25 years, a 1-dose HPV vaccination program would protect those vaccinated during their peak ages of sexual activity and prevent a similar number of HPV-related cancers as a 2-dose program, while being a more efficient use of vaccine doses.

HPV Infection and Prevention in Patients With Immune-Mediated Inflammatory Diseases: A Scoping Review

BACKGROUND/HISTORICAL PERSPECTIVE

Human papillomavirus (HPV) infections are a significant public health concern as they cause various cancers, including those of the cervix, vulva, vagina, anus, penis, and oropharynx, in both women and men.

SUMMARY INTEGRATING THE CURRENT PUBLISHED LITERATURE

Individuals with immune-mediated inflammatory diseases, particularly systemic lupus erythematosus, have an increased risk of developing persistent HPV infection and subsequent precancerous lesions due to their immunosuppression.

MAJOR CONCLUSIONS

Vaccination and screening for precancerous lesions are 2 central management strategies that must be implemented in patients with immune-mediated inflammatory diseases. Although HPV vaccination has been proven to be safe and effective in these patients, coverage remains low and should be encouraged. Screening for cervical cancer should be more widely implemented in this population, as recommended in guidelines for other immunosuppressed patients.

FUTURE RESEARCH DIRECTIONS

Catch-up vaccination, vaginal self-sampling screening for HPV detection, and therapeutic vaccination are new options that should be considered.

HPV Vaccine Usage Among the U.S. Military Academy Corps of Cadets (2018-2025)

INTRODUCTION

Human papillomavirus (HPV) is a common sexually transmitted virus that infects over 13 million people every year. Over 80% of sexually active adults will acquire HPV at some point in their lives, which is concerning since certain high-risk strains of HPV can cause six types of cancer. Vaccination against HPV is safe and effective, but despite high vaccine efficacy, vaccination rates are low among both service members and civilians.

MATERIALS AND METHODS

We conducted a retrospective, cross-sectional study to identify the percentage of United States Military Academy (USMA) Cadets who had received at least one HPV vaccine and those who completed the vaccine series. Deidentified vaccination and demographic data were retrieved from the Defense Health Agency Military Health System Data Repository (MDR) for all Cadets who were enrolled at USMA between January 2018 and May 2022 (graduating classes of 2018-2025). To identify the population of Cadets for our study and confirm presence of "any" vaccine in the MDR, Tdap vaccination information was also retrieved. The study population was defined as any Cadet who was enrolled at USMA between January 2018 and May 2022 (graduating classes of 2018-2025) and had record of an HPV and/or Tdap vaccine in the MDR. We compared demographic information between the identified population and known demographics of the USMA population to confirm that the retrieved data were consistent with population demographics. Descriptive statistics were performed to identify demographic differences based on vaccinated and unvaccinated Cadets and to determine the percentage of Cadets who received at least one HPV vaccine. Vaccine series completion was defined as the receipt of three HPV vaccine doses among those who reported receiving at least one dose of HPV vaccine or two doses if vaccinated before the age 15.

RESULTS

A total of 9,567 Cadets were assessed for eligibility with 9,433 having Tdap and/or HPV vaccine on record. Of these Cadets, 5,738/9,433 (60.8%) had received at least one HPV vaccine. Of those starting the series, 4,492 completed the two- or three-dose series for a completion rate of 47.6%. We found HPV vaccine completion rate among female Cadets (55.6%) is higher than that of male Cadets (45.2%). More Cadets from minority groups received one vaccine; however, full completion rates were similar for both the groups (48.1%). In contrast, the percentage of Cadets vaccinated against Tdap was 97.2%. Most of those vaccinated received their first vaccine between the ages of 11 and 15 (53.0%) and their final vaccine after they turned 16 (68.9%).

CONCLUSION

Though the vaccination rate among the Corps of Cadets is comparable to the public, it is still less than the 80.0% goal set by the Healthy People 2030 objective. Based on these results, we recommend that the USMA modify its policy on HPV vaccine administration to encourage more vaccine uptake. We also conclude that further studies on the rationale for avoiding the vaccine are necessary to better inform educational campaigns and mitigate stigma.

Recommendations for Adult Immunization by the Korean Society of Infectious Diseases, 2023: Minor Revisions to the 3rd Edition

The Korean Society of Infectious Diseases has been regularly developing guidelines for adult immunization since 2007. In 2023, the guidelines for the following seven vaccines were revised: influenza, herpes zoster, pneumococcal, tetanus-diphtheria-pertussis (Tdap), human papillomavirus (HPV), meningococcal, and rabies vaccines. For the influenza vaccine, a recommendation for enhanced vaccines for the elderly was added. For the herpes zoster vaccine, a recommendation for the recombinant zoster vaccine was added. For the pneumococcal vaccine, the current status of the 15-valent pneumococcal conjugate vaccine and 20-valent PCV was described. For the Tdap vaccine, the possibility of using Tdap instead of tetanus-diphtheria vaccine was described. For the HPV vaccine, the expansion of the eligible age for vaccination was described. For the meningococcal vaccine, a recommendation for the meningococcal B vaccine was added. For the rabies vaccine, the number of pre-exposure prophylaxis doses was changed. This manuscript documents the summary and rationale of the revisions for the seven vaccines. For the vaccines not mentioned in this manuscript, the recommendations in the 3rd edition of the Vaccinations for Adults textbook shall remain in effect.

Global perspectives of determinants influencing HPV vaccine introduction and scale-up in low- and middle-income countries

Achieving WHO cervical cancer elimination goals will necessitate efforts to increase HPV vaccine access and coverage in low-and-middle-income countries (LMICs). Although LMICs account for the majority of cervical cancer cases globally, scale-up of HPV vaccine programs and progress toward coverage targets in LMICs has been largely insufficient. Understanding the barriers and facilitators that stakeholders face in the introduction and scale-up of HPV vaccination programs will be pivotal in ensuring that LMICs are equipped to optimize the implementation of HPV vaccination programs. This qualitative study interviewed 13 global stakeholders categorized as either academic partners or global immunization partners to ascertain perspectives regarding factors affecting the introduction and scale-up of HPV vaccination programs in LMICs. Global stakeholders were selected as their perspectives have not been as readily highlighted within the literature despite their key role in HPV vaccination programming. The results of this investigation identified upstream (e.g., financial considerations, vaccine prioritization, global supply, capacity and delivery, and vaccine accessibility, equity, and ethics) and downstream (e.g., vaccine acceptability and hesitancy, communications, advocacy, and social mobilization) determinants that impact program introduction and scale-up and confirmed that strong political commitment and governance are significant in garnering support for HPV vaccines. As LMICs introduce HPV vaccines into their national immunization programs and develop plans for scaling up vaccination efforts, strategic approaches to communications and advocacy will also be needed to successfully meet coverage targets.

Evaluating the cost-effectiveness of HPV vaccination for adolescent girls in Japan: A comparison of 2-valent, 4-valent, and 9-valent HPV vaccines with consideration of cross-protection

OBJECTIVE

In April 2023, the Japanese Health Ministry panel approved the inclusion of the 9-valent human papillomavirus (9vHPV) vaccine in the National Immunization Program, alongside the 2-valent (2vHPV) and 4-valent HPV (4vHPV) vaccines. In response to this, we evaluated the cost-effectiveness of these three vaccines for routine immunization of girls aged 12-16 in Japan, considering the cross-protection of 2vHPV and 4vHPV vaccines.

METHODS

We constructed an age-structured mathematical model for HPV transmission, aiming to quantify the economic and epidemiological effects of various HPV vaccination strategies over a 70-year period in Japan. We determined incremental costs and quality-adjusted life years (QALYs) for each strategy, applying a 3% annual discount. Univariate and probabilistic sensitivity analyses were conducted to assess the uncertainty of our model results, with all evaluations done in 2023.

RESULTS

Our projections indicate that the HPV vaccination program in Japan will significantly reduce the incidence of HPV-related diseases. All HPV vaccination strategies, using the 2vHPV, 4vHPV, and 9vHPV vaccines, were found to be cost-effective compared to no vaccination, with incremental cost-effectiveness ratios of ¥971,447/QALY, ¥1,237,297/QALY, and ¥742,084/QALY, respectively. Direct comparisons between vaccines demonstrated that the 9vHPV vaccination was more cost-effective than the 2vHPV vaccination, whereas 4vHPV vaccination was dominated by 2vHPV vaccination.

CONCLUSIONS

Our study validates the cost-effectiveness of implementing the 9vHPV vaccine as the primary option over the 2vHPV or 4vHPV vaccine for girls in Japan. These findings underscore the need to improve the acceptance rate and coverage of HPV vaccinations in the country.

Human Papillomavirus Vaccination Status and Correlates Among Mid-Adult Women: Connecticut, USA, 2016-2019

Background: In 2019, the CDC expanded their recommendations for human papillomavirus (HPV) vaccination beyond age 26 years to include shared clinical decision-making (SCDM) among adults aged 27-45 years ("mid-adults"). The purpose of this study was to describe HPV vaccination status among mid-adult women before the implementation of SCDM for HPV vaccination. Methods: A cross-sectional survey was conducted during 2016-2019 in Connecticut, United States, and enrolled women born in 1981 or later (birth cohorts eligible for HPV vaccination). This analysis was restricted to participants aged 27 years and older at the time of the survey. Correlates of vaccination status, sources of vaccine information, and reasons for not receiving the vaccine were examined. Results: Among 298 participants, 64.4% had not received HPV vaccine. Other than age (younger age was associated with being vaccinated), no other demographic or behavioral correlates were associated with vaccination. Compared with unvaccinated women, vaccinated women were more likely to have heard about the HPV vaccine from a doctor (odds ratio [OR] = 3.45, 95% confidence interval [CI]: 2.00-5.88) and less likely to have heard about it from television (OR = 0.23, 95% CI: 0.13-0.41). The main reasons for not being vaccinated were "vaccine not offered" (48%) and "too old" (40%). Conclusions: A majority of mid-adult women in this study were not previously vaccinated against HPV, signaling the large opportunity for SCDM with this population. This may be facilitated by ensuring health care providers and mid-adult women know about the availability and potential benefits of HPV vaccination to inform decision making.

Development and characterization of a plant-derived norovirus-like particle vaccine

BACKGROUND

Norovirus (NoV) is the most common cause of diarrheal episodes globally. Issues with in vitro cultivation systems, genetic variation, and animal models have hindered vaccine development. Plant-derived virus-like particles (VLPs) may address some of these concerns because they are highly immunogenic, can be administered by different routes, and can be rapidly produced to accommodate emerging viral strains.

METHODS

NoV VLPs (NoVLP) composed of the surface viral protein (VP) 1 of the GI and GII genogroups were produced in Nicotiana benthamiana using an Agrobacterium tumefaciens-based recombinant transient expression system. Leaves from infiltrated plants were harvested and NoVLPs were extracted and purified. The safety and immunogenicity of the GII.4 NoVLP, the genotype currently causing most human disease, were subsequently examined in rabbits and mice.

RESULTS

Fifteen GI and GII NoVLPs were successfully expressed in N. benthamiana and were structurally similar to NoV virions, as determined by cryogenic transmission electron microscopy. The NoVLP was well-tolerated, with no local or systemic signs of toxicity in rabbits. Three intramuscular doses of the GII.4 NoVLP adjuvanted with aluminum hydroxide induced robust IgG titers, IgG-secreting cells, histo-blood group antigen blocking titers, and IFNγ-secreting T cells in mice. In addition to circulating antibodies, oral administration of the NoVLP in mice induced significant IgA levels in feces, indicative of a mucosal response.

CONCLUSIONS

The plant-made NoVLP vaccine was safe and immunogenic in mice and rabbits. Multi-modal vaccination, combining oral and intramuscular administration could be considered for future clinical development to maximize systemic and mucosal immune responses.

Global impact and cost-effectiveness of one-dose versus two-dose human papillomavirus vaccination schedules: a comparative modelling analysis

BACKGROUND

To eliminate cervical cancer as a public health problem, the World Health Organization had recommended routine vaccination of adolescent girls with two doses of the human papillomavirus (HPV) vaccine before sexual initiation. However, many countries have yet to implement HPV vaccination because of financial or logistical barriers to delivering two doses outside the infant immunisation programme.

METHODS

Using three independent HPV transmission models, we estimated the long-term health benefits and cost-effectiveness of one-dose versus two-dose HPV vaccination, in 188 countries, under scenarios in which one dose of the vaccine gives either a shorter duration of full protection (20 or 30 years) or lifelong protection but lower vaccine efficacy (e.g. 80%) compared to two doses. We simulated routine vaccination with the 9-valent HPV vaccine in 10-year-old girls at 80% coverage for the years 2021-2120, with a 1-year catch-up campaign up to age 14 at 80% coverage in the first year of the programme.

RESULTS

Over the years 2021-2120, one-dose vaccination at 80% coverage was projected to avert 115.2 million (range of medians: 85.1-130.4) and 146.8 million (114.1-161.6) cervical cancers assuming one dose of the vaccine confers 20 and 30 years of protection, respectively. Should one dose of the vaccine provide lifelong protection at 80% vaccine efficacy, 147.8 million (140.6-169.7) cervical cancer cases could be prevented. If protection wanes after 20 years, 65 to 889 additional girls would need to be vaccinated with the second dose to prevent one cervical cancer, depending on the epidemiological profiles of the country. Across all income groups, the threshold cost for the second dose was low: from 1.59 (0.14-3.82) USD in low-income countries to 44.83 (3.75-85.64) USD in high-income countries, assuming one dose confers 30-year protection.

CONCLUSIONS

Results were consistent across the three independent models and suggest that one-dose vaccination has similar health benefits to a two-dose programme while simplifying vaccine delivery, reducing costs, and alleviating vaccine supply constraints. The second dose may become cost-effective if there is a shorter duration of protection from one dose, cheaper vaccine and vaccination delivery strategies, and high burden of cervical cancer.

Cervical Cancer Screening: A Review

Importance

Each year in the US, approximately 100 000 people are treated for cervical precancer, 14 000 people are diagnosed with cervical cancer, and 4000 die of cervical cancer.

Observations

Essentially all cervical cancers worldwide are caused by persistent infections with one of 13 carcinogenic human papillomavirus (HPV) genotypes: 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, and 68. HPV vaccination at ages 9 through 12 years will likely prevent more than 90% of cervical precancers and cancers. In people with a cervix aged 21 through 65 years, cervical cancer is prevented by screening for and treating cervical precancer, defined as high-grade squamous intraepithelial lesions of the cervix. High-grade lesions can progress to cervical cancer if not treated. Cervicovaginal HPV testing is 90% sensitive for detecting precancer. In the general population, the risk of precancer is less than 0.15% over 5 years following a negative HPV test result. Among people with a positive HPV test result, a combination of HPV genotyping and cervical cytology (Papanicolaou testing) can identify the risk of precancer. For people with current precancer risks of less than 4%, repeat HPV testing is recommended in 1, 3, or 5 years depending on 5-year precancer risk. For people with current precancer risks of 4% through 24%, such as those with low-grade cytology test results (atypical squamous cells of undetermined significance [ASC-US] or low-grade squamous intraepithelial lesion [LSIL]) and a positive HPV test of unknown duration, colposcopy is recommended. For patients with precancer risks of less than 25% (eg, cervical intraepithelial neoplasia grade 1 [CIN1] or histologic LSIL), treatment-related adverse effects, including possible association with preterm labor, can be reduced by repeating colposcopy to monitor for precancer and avoiding excisional treatment. For patients with current precancer risks of 25% through 59% (eg, high-grade cytology results of ASC cannot exclude high-grade lesion [ASC-H] or high-grade squamous intraepithelial lesion [HSIL] with positive HPV test results), management consists of colposcopy with biopsy or excisional treatment. For those with current precancer risks of 60% or more, such as patients with HPV-16-positive HSIL, proceeding directly to excisional treatment is preferred, but performing a colposcopy first to confirm the need for excisional treatment is acceptable. Clinical decision support tools can facilitate correct management.

Conclusions and Relevance

Approximately 100 000 people are treated for cervical precancer each year in the US to prevent cervical cancer. People with a cervix should be screened with HPV testing, and if HPV-positive, genotyping and cytology testing should be performed to assess the risk of cervical precancer and determine the need for colposcopy or treatment. HPV vaccination in adolescence will likely prevent more than 90% of cervical precancers and cancers.

Strategies to eliminate cervical cancer in China

Cervical cancer is a widely distributed disease that is preventable and controllable through early intervention. The World Health Organization has identified three key measures, coverage populations and coverage targets to eliminate cervical cancer. The WHO and several countries have conducted model predictions to determine the optimal strategy and timing of cervical cancer elimination. However, specific implementation strategies need to be developed in the context of local conditions. China has a relatively high disease burden of cervical cancer but a low human papillomavirus vaccination rate and cervical cancer screening population coverage. The purpose of this paper is to review interventions and prediction studies for the elimination of cervical cancer and to analyze the problems, challenges and strategies for the elimination of cervical cancer in China.

Accounting for Adverse Events Following Immunization in Economic Evaluation: Systematic Review of Economic Evaluations of Pediatric Vaccines Against Pneumococcus, Rotavirus, Human Papillomavirus, Meningococcus and Measles-Mumps-Rubella-Varicella

OBJECTIVES

Economic evaluations of vaccines should accurately represent all relevant economic and health consequences of vaccination, including losses due to adverse events following immunization (AEFI). We investigated to what extent economic evaluations of pediatric vaccines account for AEFI, which methods are used to do so and whether inclusion of AEFI is associated with study characteristics and the vaccine's safety profile.

METHODS

A systematic literature search (MEDLINE, EMBASE, Cochrane Systematic Reviews and Trials, Database of the Centre for Reviews and Dissemination of the University of York, EconPapers, Paediatric Economic Database Evaluation, Tufts New England Cost-Effectiveness Analysis Registry, Tufts New England Global Health CEA, International Network of Agencies for Health Technology Assessment Database) was performed for economic evaluations published between 2014 and 29 April 2021 (date of search) pertaining to the five groups of pediatric vaccines licensed in Europe and the United States since 1998: the human papillomavirus (HPV) vaccines, the meningococcal vaccines (MCV), the measles-mumps-rubella-varicella (MMRV) combination vaccines, the pneumococcal conjugate vaccines (PCV) and the rotavirus vaccines (RV). Rates of accounting for AEFI were calculated, stratified by study characteristics (e.g., region, publication year, journal impact factor, level of industry involvement) and triangulated with the vaccine's safety profile (Advisory Committee on Immunization Practices [ACIP] recommendations and information on safety-related product label changes). The studies accounting for AEFI were analyzed in terms of the methods used to account for both cost and effect implications of AEFI.

RESULTS

We identified 112 economic evaluations, of which 28 (25%) accounted for AEFI. This proportion was significantly higher for MMRV (80%, four out of five evaluations), MCV (61%, 11 out of 18 evaluations) and RV (60%, nine out of 15 evaluations) compared to HPV (6%, three out of 53 evaluations) and PCV (5%, one out of 21 evaluations). No other study characteristics were associated with a study's likelihood of accounting for AEFI. Vaccines for which AEFI were more frequently accounted for also had a higher frequency of label changes and a higher level of attention to AEFI in ACIP recommendations. Nine studies accounted for both the cost and health implications of AEFI, 18 studies considered only costs and one only health outcomes. While the cost impact was usually estimated based on routine billing data, the adverse health impact of AEFI was usually estimated based on assumptions.

DISCUSSION

Although (mild) AEFI were demonstrated for all five studied vaccines, only a quarter of reviewed studies accounted for these, mostly in an incomplete and inaccurate manner. We provide guidance on which methods to use to better quantify the impact of AEFI on both costs and health outcomes. Policymakers should be aware that the impact of AEFI on cost-effectiveness is likely to be underestimated in the majority of economic evaluations.

Health care provider knowledge around shared clinical decision-making regarding HPV vaccination of adults aged 27-45 years in the United States

BACKGROUND

The Advisory Committee on Immunization Practices (ACIP) recommends shared clinical decision-making (SCDM) regarding HPV vaccination for adults aged 27-45 years who are not adequately vaccinated. The objective of this survey was to understand physician knowledge, attitudes, and practices regarding HPV vaccination in this age group.

METHODS

An online survey was administered in June 2021 to physicians who reported practicing internal medicine, family medicine, or obstetrics and gynecology (targeted N = 250 in each practice specialty), selected randomly from potentially eligible physicians from a panel of 2 million U.S. health care providers.

RESULTS

In total, 753 physicians participated in the survey: 33.3% practiced internal medicine, 33.1% practiced family medicine, and 33.6% practiced obstetrics/gynecology; 62.5% were male and mean physician age was 52.7 years. Despite the COVID-19 pandemic, at least a third of participating physicians in each practice specialty reported having more HPV vaccine SCDM discussions with patients aged 27-45 years in the past 12 months. While a majority of physicians (79.7%) reported being aware of the SCDM recommendation for adults in this age group, only half of physicians answered an objective knowledge question about SCDM recommendations correctly.

CONCLUSIONS

Findings suggest that there are physician knowledge gaps related to SCDM for HPV vaccination. To improve access to HPV vaccination for people most likely to benefit, increasing availability and use of decision aids to support SCDM discussions might help healthcare providers and patients jointly make the most informed decisions about HPV vaccination.

Adjuvant Human Papillomavirus Vaccination After Excisional Procedure for Cervical Intraepithelial Neoplasia: A Cost-Effectiveness Analysis

OBJECTIVE

To examine the cost effectiveness of human papillomavirus (HPV) vaccination after excisional procedure compared with no vaccination.

METHODS

We constructed a decision-analytic model (TreeAge Pro 2021) to compare outcomes between patients who underwent an excisional procedure followed by nonavalent HPV vaccination to those who underwent an excisional procedure without vaccination. Our theoretical cohort contained 250,000 patients, the approximate number undergoing excisional procedures annually in the United States. Our outcomes were costs, quality-adjusted life-years (QALYs), recurrence events, number of surveillance Pap tests with co-testing, number of colposcopies, and second excisional procedures. Probabilities of recurrence were based on a recently published meta-analysis. All values were derived from the literature, and QALYs were discounted at a rate of 3%. Outcomes were applied for 4 years after the initial excisional procedure. Our cost-effectiveness threshold was $100,000 per QALY. Sensitivity analyses were performed to evaluate the robustness of the model.

RESULTS

In our theoretical cohort of patients who underwent an excisional procedure, the HPV vaccination strategy was associated with 17,281 fewer recurrences of cervical intraepithelial neoplasia (CIN) (8,360 fewer cases of CIN 1 and 8,921 fewer cases of CIN 2 or 3), 26,203 fewer Pap tests (1,025,368 vs 1,051,570), 17,281 fewer colposcopies (20,588 vs 37,869), and 8,921 fewer second excisional procedures (4,779 vs 13,701). The vaccination strategy was associated with a higher cost of $135 million. Vaccination was a cost-effective strategy, with an incremental cost-effectiveness ratio of $29,181 per QALY, compared with no vaccination. In our sensitivity analyses, the HPV vaccination strategy remained cost effective until the cost of the three-dose HPV vaccine series reached $1,899 or the baseline (nonvaccinated) probability of recurrence was less than 4.8%.

CONCLUSION

In our model, HPV vaccination for patients with a prior excisional procedure led to improved outcomes and was cost effective. Our study suggests that clinicians should consider offering the three-dose HPV vaccine series to patients who have undergone an excisional procedure to decrease the risk of CIN recurrence and its sequelae.

Updated estimate of the annual direct medical cost of screening and treatment for human papillomavirus associated disease in the United States

The annual direct medical cost attributable to human papillomavirus (HPV) in the United States over the period 2004-2007 was estimated at $9.36 billion in 2012 (updated to 2020 dollars). The purpose of this report was to update that estimate to account for the impact of HPV vaccination on HPV-attributable disease, reductions in the frequency of cervical cancer screening, and new data on the cost per case of treating HPV-attributable cancers. Based primarily on data from the literature, we estimated the annual direct medical cost burden as the sum of the costs of cervical cancer screening and follow-up and the cost of treating HPV-attributable cancers, anogenital warts, and recurrent respiratory papillomatosis (RRP). We estimated the total direct medical cost of HPV to be $9.01 billion annually over the period 2014-2018 (2020 U.S. dollars). Of this total cost, 55.0% was for routine cervical cancer screening and follow-up, 43.8% was for treatment of HPV-attributable cancer, and less than 2% was for treating anogenital warts and RRP. Although our updated estimate of the direct medical cost of HPV is slightly lower than the previous estimate, it would have been substantially lower had we not incorporated more recent, higher cancer treatment costs.

Prevention Strategies and Early Diagnosis of Cervical Cancer: Current State and Prospects

Cervical cancer ranks third among all new cancer cases and causes of cancer deaths in females. The paper provides an overview of cervical cancer prevention strategies employed in different regions, with incidence and mortality rates ranging from high to low. It assesses the effectiveness of approaches proposed by national healthcare systems by analysing data published in the National Library of Medicine (Pubmed) since 2018 featuring the following keywords: "cervical cancer prevention", "cervical cancer screening", "barriers to cervical cancer prevention", "premalignant cervical lesions" and "current strategies". WHO's 90-70-90 global strategy for cervical cancer prevention and early screening has proven effective in different countries in both mathematical models and clinical practice. The data analysis carried out within this study identified promising approaches to cervical cancer screening and prevention, which can further enhance the effectiveness of the existing WHO strategy and national healthcare systems. One such approach is the application of AI technologies for detecting precancerous cervical lesions and choosing treatment strategies. As such studies show, the use of AI can not only increase detection accuracy but also ease the burden on primary care.

Clinical and Public Health Considerations for HPV Vaccination in Midadulthood: A Narrative Review

Human papillomavirus (HPV) is an important cause of anogenital and oropharyngeal cancers, anogenital warts, and recurrent respiratory papillomatosis. Beginning in 2019, US guidelines recommended shared clinical decision-making (SCDM) for HPV vaccination among midadults (27-45 years). We conducted a narrative review of existing literature on HPV vaccination in midadults. The available evidence demonstrates that HPV vaccination in midadults is safe, efficacious, and likely to benefit both HPV-naïve midadults and those with previous infections. However, gaps in knowledge related to HPV vaccination have been identified among clinicians and midadult patients. Universal midadult HPV vaccination in the United States could avert 20 934-37 856 cancer cases over 100 years, costing $141 000-$1 471 000 per quality-adjusted life-year gained. Wide variation in these estimates reflects uncertainties in sexual behavior, HPV natural history, and naturally acquired immunity. Greater awareness among clinicians and midadult patients and broad implementation of SCDM may accelerate progress toward eliminating HPV-associated cancers and other diseases.

Human Papillomavirus Vaccine Administration Trends Among Commercially Insured US Adults Aged 27-45 Years Before and After Advisory Committee on Immunization Practices Recommendation Change, 2007-2020

Importance

In 2019, the Advisory Committee on Immunization Practices (ACIP) recommended patient-clinician shared decision-making for human papillomavirus (HPV) vaccination in adults aged 27 to 45 years. Less is known about the HPV vaccine administration trends in this age group before and after this recommendation update.

Objective

To examine the association between the ACIP recommendation update and the HPV vaccine administration among US adults aged 27 to 45 years.

Design, Setting, and Participants

This large commercial claim-based retrospective cohort study used the Optum Clinformatics database for validated claims from January 1, 2007, through December 31, 2020. A total of 22 600 520 US adults aged 27 to 45 years without previous HPV vaccination claims during the study and enrollment period were included.

Main Outcomes and Measures

The first-appearing HPV vaccination claim per individual was defined as a new HPV vaccine administration. Interrupted time-series analyses were conducted to assess the association between the ACIP update and the quarterly vaccine administration rate change. The annual rate trends across race and ethnicity groups and the proportions of vaccination cases by sub-age groups and valent types were also estimated. Vaccine administration trends were assessed by race and ethnicity in this age group because HPV vaccination trends were found to differ by race and ethnicity in the initially eligible population.

Results

Among 22 600 520 final study participants, the majority were men (50.9%) and non-Hispanic White (53.4%), and the mean (SD) age when first observed was 34.6 (5.8) years. In women, the ACIP update was associated with an immediate increase in vaccine administration rate (coefficient β2, 40.18 per 100 000 persons; P = .01) and an increased slope (coefficient β3, 9.62 per 100 000 persons per quarter; P = .03) over time postupdate. The ACIP update was only associated with an immediate increase in vaccine administration in men (coefficient β2, 27.54; P < .001). The annual rate trends were similar across race and ethnicity groups. Age at vaccine administration shifted over time (eg, women aged 40-45 years comprised only 4.9% of vaccinations in 2017, then 19.0% in 2019, and 22.7% in 2020). The most administered HPV vaccines in 2020 were 9 valent (women, 97.0%; men, 97.7%).

Conclusions and Relevance

In this population-based cohort study, there were statistically significant increases in HPV vaccine administration in adults aged 27 to 45 years after the ACIP recommendation update. Patient-clinician shared decision-making may have been the main associated factor for this increase. Further research is warranted to explore the decision-making process in receiving HPV vaccination and to develop effective decision aids to maximize the cancer prevention benefit in this age group.

The associations of tobacco use, sexually transmitted infections, HPV vaccination, and screening with the global incidence of cervical cancer: an ecological time series modeling study

OBJECTIVES

We aimed to quantify the temporal associations between cervical cancer incidence and cervical cancer-related factors and to predict the number of new cervical cancer cases averted under counterfactual scenarios compared to the status quo scenario.

METHODS

We described temporal trends in cervical cancer and associated factors globally from 1990 to 2019. We then used generalized linear mixed models to explore the impact of tobacco use, sexually transmitted infections (STIs), human papillomavirus (HPV) vaccination, and cervical screening on cervical cancer incidence. A counterfactual analysis was performed to simulate the most effective scenario for reducing cervical cancer incidence.

RESULTS

The worldwide incidence of cervical cancer showed a downward trend over the past 3 decades (estimated annual percentage change, -0.72%), although the incidence remained high (>30 cases per 100,000 persons) in sub-Saharan Africa, Latin America, and the Caribbean. Higher smoking and STI prevalence showed significant direct associations with the incidence of cervical cancer, whereas HPV vaccination and screening coverage showed significant inverse associations. If the strategic goals for accelerating the elimination of cervical cancer and tobacco control programs had been achieved in 2019, the largest decrease in the number of new cervical cancer cases would have been observed, with 54,169 fewer new cases of cervical cancer in 2019.

CONCLUSIONS

Our counterfactual analysis found that a comprehensive intervention program emphasizing scaled-up cervical screening coverage (70%), HPV vaccination coverage (90%), and tobacco control (30% relative reduction) would be the most effective program for reducing cervical cancer incidence.

Comparison of HPV neutralizing and IgG antibodies in unvaccinated female adolescents

Aims: To analyze the consistency between HPV neutralizing antibodies and specific total IgG antibodies in unvaccinated females. Materials & methods: Serum samples from 978 unvaccinated Chinese females aged 9-26 years were measured for antibodies against HPV-16 and HPV-18 using simultaneous pseudovirus-based neutralization assay and ELISA. Results: There was a moderate level of consistency between HPV neutralizing antibodies and specific IgG in females aged 18-26 years (Cohen's κ coefficient for HPV-16 and HPV-18: 0.52 and 0.38) and poor consistency in those aged 9-17 years (Cohen's κ coefficient <0.05). However, Cohen's κ coefficient remained almost unchanged in sensitivity analysis when the IgG antibody cut-off value was raised. Conclusion: HPV neutralizing antibodies are a more specific indicator for the evaluation of HPV natural humoral immunity.

Data-Related Challenges in Cost-Effectiveness Analyses of Vaccines

Cost-effectiveness analyses (CEAs) are often prepared to quantify the expected economic value of potential vaccination strategies. Estimated outcomes and costs of vaccination strategies depend on numerous data inputs or assumptions, including estimates of vaccine efficacy and disease incidence in the absence of vaccination. Limitations in epidemiologic data can meaningfully affect both CEA estimates and the interpretation of those results by groups involved in vaccination policy decisions. Developers of CEAs should be transparent with regard to the ambiguity and uncertainty associated with epidemiologic information that is incorporated into their models. We describe selected data-related challenges to conducting CEAs for vaccination strategies, including generalizability of estimates of vaccine effectiveness, duration and functional form of vaccine protection that can change over time, indirect (herd) protection, and serotype replacement. We illustrate how CEA estimates can be sensitive to variations in specific epidemiologic assumptions, with examples from CEAs conducted for the USA that assessed vaccinations against human papillomavirus and pneumococcal disease. These challenges are certainly not limited to these two case studies and may be relevant to other vaccines.

Sex and educational attainment differences in HPV knowledge and vaccination awareness among unvaccinated-sexually active adults in Puerto Rico

Human papillomavirus (HPV) knowledge and HPV vaccination uptake remain suboptimal. We assessed sex and educational attainment differences in HPV knowledge and vaccine awareness. Data from a cross-sectional study (2018–2021) in Puerto Rico among adults aged 21–49 was analyzed (n = 278). Adequate knowledge was defined as a score of ≥70% of correct responses on a 13-item knowledge scale. Multivariable logistic regression was used to assess the association of sex (men vs. women) and education (high school or less vs. more than high school) categories with adequate HPV knowledge and vaccine awareness. Adequate HPV knowledge was higher among women (53%) and men (46%) with more than high school and was lower among women (46%) and men (27%) with high school or less. For HPV vaccine awareness, similar results were observed. Women (OR = 3.0 ; 95%CI = 1.4–6.2) and men (OR = 2.3 , 95%CI = 1.1–4.8) with more than high school and women with high school or less (OR = 2.3 , 95%CI = 1.0–5.2) were more likely to have adequate HPV vaccine knowledge than men with high-school or less education. Heightened HPV vaccine awareness was also seen among more educated women and men and women with similar lower education when compared to men with ≤ high school. Men and individuals with lower educational attainment were more likely to have inadequate HPV knowledge and vaccine awareness. HPV vaccine-oriented educational interventions should target these high-risk groups.

Long-term impact of HPV vaccination and COVID-19 pandemic on oropharyngeal cancer incidence and burden among men in the USA: A modeling study

BACKGROUND

Oropharyngeal cancer (OPC) incidence is rising rapidly among men in the United States of America (USA). We aimed to project the impact of maintaining the current HPV vaccination uptake and achieving 80% national (Healthy People) goal on OPC incidence and burden.

METHODS

We developed an open-cohort micro-simulation model of OPC natural history among contemporary and future birth cohorts of men, accounting for sexual behaviors, population growth, aging, and herd immunity. We used data from nationally representative databases, cancer registries from all 50 states, large clinical trials, and literature. We evaluated the status quo scenario (the current HPV vaccination uptake remained stable) and alternative scenarios of improvements in uptake rates in adolescents (aged 9-17 years) and young adults (aged 18-26 years) by 2025 to achieve and maintain the 80% goal. The primary outcome was to project OPC incidence and burden from 2009 to 2100. We also assessed the impact of disruption in HPV vaccine uptake during the COVID-19 pandemic.

FINDINGS

OPC incidence is projected to rise until the mid-2030s, reaching the age-standardized incidence rate of 9·8 (95% uncertainty interval [UI] 9·5-10·1) per 100 000 men, with the peak annual burden of 23 850 (UI, 23 200-24 500) cases. Under the status quo scenario, HPV vaccination could prevent 124 000 (UI, 117 000-131 000) by 2060, 400 000 (UI, 384 000-416 000) by 2080, and 792 000 (UI, 763 000-821 000) by 2100 OPC cases among men. Achievement and maintenance of 80% coverage among adolescent girls only, adolescent girls and boys, and adolescents plus young adults could prevent an additional number of 100 000 (UI, 95 000-105 000), 118 000 (UI, 113 000-123 000), and 142 000 (UI, 136 000-148 000) male OPC cases by 2100. Delayed recovery of the HPV vaccine uptake during the COVID-19 pandemic could lead to 600 (UI, 580-620) to 6200 (UI, 5940-6460) additional male OPC cases by 2100, conditional on the decline in the extent of the national HPV vaccination coverage and potential delay in rebounding.

INTERPRETATION

Oropharyngeal cancer burden is projected to rise among men in the USA. Nationwide efforts to achieve the HPV vaccination goal of 80% coverage should be a public health priority. Rapid recovery of the declined HPV vaccination uptake during the COVID-19 pandemic is also crucial to prevent future excess OPC burden.

FUNDING

National Cancer Institute and National Institute on Minority Health and Health Disparities of the USA.

HPV vaccination among seropositive, DNA negative cohorts: a systematic review & meta-analysis

Objective

Vaccine efficacy among previously exposed, but currently uninfected women, i.e., those who have serological evidence of a prior human papillomavirus (HPV) infection without corresponding detectable HPV DNA, remains incompletely defined. This meta-analysis assessed the serotype-specific efficacy of prophylactic HPV vaccination against HPV16/18 persistent infection (PI) and cervical intraepithelial neoplasia (CIN) among seropositive, DNA negative (SPDN) women enrolled to randomized controlled trials (RCTs) of HPV L1-based vaccines.

Methods

Searches were conducted on 08/16/20 on MEDLINE, Embase, Scopus and CENTRAL. RCTs of L1-based prophylactic bivalent or quadrivalent HPV vaccines, reporting serotype-specific clinical efficacy endpoints in the HPV16/18 seropositive, DNA-negative populations were included. Relative risks (RRs) of 6-month PI (6mPI), 12-month PI (12mPI), CIN1+ and CIN2+ were pooled using a random-effects model.

Results

A total of 1,727 citations were reviewed. 8 studies, with a total of 9,569 SPDN participants, met all eligibility criteria. The RR of 6mPI (RR=0.22; 95% confidence interval [CI]=0.08–0.61; p=0.018), 12mPI (RR=0.20; 95% CI=0.05–0.80; p=0.035), CIN1+ (RR=0.13; 95% CI=0.05–0.30; p=0.003) and CIN2+ (RR=0.15; 95% CI=0.04–0.59; p=0.022) was significantly reduced in the vaccinated compared to the unvaccinated group.

Conclusion

Our findings suggest high serotype-specific efficacy for HPV vaccination among cohorts of women with evidence of prior HPV16/18 infections, including 87% efficacy (95% CI=70%–95%; p=0.003) against HPV16/18 cervical dysplasia. HPV vaccination is highly effective among uninfected women, regardless of prior exposure history.

Trial Registration

PROSPERO Identifier: CRD42020206888

Increasing HPV vaccination coverage to prevent oropharyngeal cancer: A cost-effectiveness analysis

The incidence of oropharyngeal cancer (OPC) has been rising, especially among middle-aged men. While Human Papillomavirus (HPV) has been irrevocably implicated in the pathogenesis of oropharyngeal cancer (OPC), the current HPV vaccination uptake rate remains low in the US. The aim of our study was to evaluate the impact of increased HPV vaccination coverage on HPV-associated OPC incidence and costs. A decision analytic model was constructed for hypothetical cohorts of 9-year-old boys and girls. Two strategies were compared: 1) Maintaining the current vaccination uptake rates; 2) Increasing HPV vaccination uptake rates to the Healthy People 2030 target (80%) for both sexes. Increasing HPV vaccination coverage rates to 80% would be expected to prevent 5,339 OPC cases at a cost of $0.57 billion USD. Increased HPV vaccination coverage would result in 7,430 quality-adjusted life year (QALY) gains in the overall population, and it is estimated to be cost-effective for males with an incremental cost-effectiveness ratio of $86,940 per QALY gained under certain conditions. Expanding HPV vaccination rates would likely provide a cost-effective way to reduce the OPC incidence, particularly among males.

Median Age at HPV Infection Among Women in the United States: A Model-Based Analysis Informed by Real-world Data

Background

The US Advisory Committee for Immunization Practices (ACIP) recommended shared clinical decision-making for human papillomavirus (HPV) vaccination of individuals aged 27 to 45 years (mid-adults) in June 2019. Determining the median age at causal HPV infection and CIN2+ diagnosis based on the natural history of HPV disease can help elucidate the incidence of HPV infections and the potential benefits of vaccination in mid-adults.

Methods

Real-world data on CIN2+ diagnosis from the prevaccine era were sourced from a statewide surveillance registry in Connecticut. Age distribution of CIN2+ diagnosis in 2008 and 2009 was estimated. A discrete event simulation model was developed to predict the age distribution of causal HPV infection. The optimal age distribution of causal HPV infection provided the best goodness-of-fit statistic to compare the predicted vs real-world age distribution of CIN2+ diagnosis.

Results

The median age at CIN2+ diagnosis from 2008 through 2009 in Connecticut was 28 years. The predicted median age at causal HPV infection was estimated to be 23.9 years. There was a difference of 5.2 years in the median age at acquisition of causal HPV infection and the median age at CIN2+ diagnosis.

Conclusions

Real-world data on CIN2+ diagnosis and model-based analysis indicate a substantial burden of infection and disease among women aged 27 years or older, which supports the ACIP recommendation to vaccinate some mid-adults. When natural history is known, this novel approach can also help determine the timing of causal infections for other commonly asymptomatic infectious diseases.

Impact of disruptions and recovery for established cervical screening programs across a range of high-income country program designs, using COVID-19 as an example: A modelled analysis

COVID-19 has disrupted cervical screening in several countries, due to a range of policy-, health-service and participant-related factors. Using three well-established models of cervical cancer natural history adapted to simulate screening across four countries, we compared the impact of a range of standardised screening disruption scenarios in four countries that vary in their cervical cancer prevention programs. All scenarios assumed a 6- or 12-month disruption followed by a rapid catch-up of missed screens. Cervical screening disruptions could increase cervical cancer cases by up to 5-6%. In all settings, more than 60% of the excess cancer burden due to disruptions are likely to have occurred in women aged less than 50 years in 2020, including settings where women in their 30s have previously been offered HPV vaccination. Approximately 15-30% of cancers predicted to result from disruptions could be prevented by maintaining colposcopy and precancer treatment services during any disruption period. Disruptions to primary screening had greater adverse effects in situations where women due to attend for screening in 2020 had cytology (vs. HPV) as their previous primary test. Rapid catch-up would dramatically increase demand for HPV tests in 2021, which it may not be feasible to meet because of competing demands on the testing machines and reagents due to COVID tests. These findings can inform future prioritisation strategies for catch-up that balance potential constraints on resourcing with clinical need.

Projected Association of Human Papillomavirus Vaccination With Oropharynx Cancer Incidence in the US, 2020-2045

Importance

Oropharynx cancer (OPC) incidence has increased for several decades in the US. It is unclear when and how this trend will be affected by current HPV vaccination trends.

Objective

To assess the association of HPV vaccination with future OPC incidence in the US.

Design, Setting, and Participants

This population-based age-period-cohort analysis obtained OPC incidence data from the Surveillance, Epidemiology, and End Results program from 69 562 patients 34 to 83 years of age diagnosed with OPC. The HPV vaccination data were obtained from the National Immunization Survey-Teen (60 124 participants) and National Health Interview Survey (16 904 participants). Data were collected from January 1, 1992, to December 31, 2017. Age-period-cohort forecasting models projected expected 2018 to 2045 OPC incidence under a counterfactual scenario of no HPV vaccination and current levels of HPV vaccination, stratifying by sex. Data analyses were completed by December 2020.

Exposures

Age- and sex-specific cumulative prevalence of HPV vaccination in 2016 to 2017 projected forward.

Main Outcomes and Measures

Projected OPC incidence and number of OPC cases expected to be prevented by HPV vaccination.

Results

Under current HPV vaccination rates, between 2018 and 2045, OPC incidence is projected to decrease in younger individuals (36-45 years of age: from 1.4 to 0.8 per 100 000 population; 46-55 years of age: from 8.7 to 7.2 per 100 000 population) but continue to increase among older individuals (70-83 years of age: from 16.8 to 29.0 per 100 000 population). The association of HPV vaccination with overall OPC incidence through 2045 will remain modest (no vaccination vs vaccination: 14.3 vs 13.8 per 100 000 population in 2045). By 2045 HPV vaccination is projected to reduce OPC incidence among individuals 36 to 45 years of age (men: 48.1%; women: 42.5%) and 46 to 55 years of age (men: 9.0%; women: 22.6%), but among those 56 years or older, rates are not meaningfully reduced. Between 2018 and 2045, a total of 6334 OPC cases will be prevented by HPV vaccination, of which 88.8% of such cases occur in younger age (≤55 years) groups.

Conclusions and Relevance

According to the projections of this population-based age-period-cohort study, current HPV vaccination rates will have a limited association with overall OPC incidence through 2045 because older individuals who have not yet been vaccinated remain at high risk for OPC. However, reductions in OPC incidence should occur among young and middle-aged adults, the group at lowest risk of diagnosis. These findings forecast a continued shift in the landscape of OPC to an older population.

Naturally acquired HPV antibodies against subsequent homotypic infection: A large-scale prospective cohort study

Background

Although recent studies have suggested that naturally acquired Human papillomavirus (HPV) antibodies are partly protective against subsequent homotypic infection, the extent of protection remains indecisive. Here, we evaluate the protective effect of neutralizing and IgG antibodies simultaneously.

Methods

In a cohort of 3634 women aged 18-45 years from the control arm of a phase III trial of the HPV-16/18 bivalent vaccine, participants were tested for neutralizing antibodies by pseudovirion-based neutralization assay (PBNA) and IgG antibodies by enzyme-linked immunosorbent assay (ELISA) at baseline. HPV-16/18 incident and persistent infections were identified using cervical specimens periodically collected during the 5·5 years of follow-up. The protective effects of HPV-16/18 neutralizing and IgG antibodies against homotypic infection were assessed using a Cox proportional hazard model.

Findings

For the persistent infection (PI) endpoints of HPV-16/18 lasting for over 6/12 months, a prevalence of type-specific neutralizing antibodies was highly protective (6-month PI: hazard ratio (HR) = 0·16, 95% confidence interval (CI): 0·04, 0·65; 12-month PI: HR = 0·23, 95% CI: 0·06, 0·94), whereas a prevalence of IgG antibodies was associated with minor and non-significant protection (6-month PI: HR = 0·66, 95% CI: 0·40, 1·09; 12-month PI: HR = 0·66, 95% CI: 0·36, 1·20). After increasing the cut-off value to the median IgG level, the risk of 6-month PI was significantly lower in seropositive vs seronegative women (HR = 0·38, 95% CI: 0·18, 0·83).

Interpretation

Naturally acquired antibodies are associated with a substantially reduced risk of subsequent homotypic infection.

Funding

NSFC; The Fujian Province Health Education Joint Research Project; Xiamen Science and Technology Major Project; CIFMS; and Xiamen Innovax.

Eliminating Cervical Cancer: Progress and Challenges for High-income Countries

In 2020, the World Health Organization launched a major initiative to eliminate cervical cancer globally. The initiative is built around the three key pillars of human papillomavirus (HPV) vaccination, cervical screening and treatment, with associated intervention targets for the year 2030. The '90-70-90' targets specify that 90% of adolescent girls receive prophylactic HPV vaccination, 70% of adult women receive a minimum twice-in-a-lifetime cervical HPV test and 90% receive appropriate treatment for preinvasive or invasive disease. Modelling has shown that if these targets are met, the elimination of cervical cancer, defined as fewer than four cases per 100 000 women per annum, will be achieved within a century. Many high-income countries are well positioned to eliminate cervical cancer within the coming decades, but few have achieved '90-70-90' and many challenges must still be addressed to deliver these critical interventions effectively. This review considers the current status of cervical cancer control in relation to each of the three elimination pillars in high-income countries and discusses some of the developments that will assist countries in reaching these ambitious targets by 2030.

Human papillomavirus vaccination in adults: impact, opportunities and challenges - a meeting report

For more than a decade human papillomavirus (HPV) vaccine have been implemented in most high-income countries, and more recently also in several low- and middle-income countries. The vaccines are safe and their impact and effectiveness in preventing HPV vaccine type infection and associated diseases has been thoroughly established. Currently, the primary recommended cohorts for immunisation are adolescents, 9-15 years of age but HPV is an ubiquitous infection that is mainly (but not exclusively) sexually transmitted. Sexually active adults remain susceptible to infection and continued transmission of the virus, representing a reservoir of infection in the population. A recent meeting, conducted by the HPV Prevention and Control Board (HPV-PCB), reviewed the current status of HPV vaccination of adults, discussed limitations, challenges and benefits of HPV vaccination of adults, evaluated the effectiveness of HPV vaccination after treatment of post cervical cancer and precancerous lesions, and discussed the potential impact of adult vaccination on cervical cancer elimination strategies in light of the current and future HPV vaccine shortage. HPV-PCB is an independent multidisciplinary board of international experts that disseminates relevant information on HPV to a broad array of stakeholders and provides guidance on strategic, technical and policy issues in the implementation of HPV prevention and control programs. The HPV-PCB concluded that, given the current data available on adult HPV vaccination and the ongoing vaccine supply constraints, it is too early to implement routine vaccination of adults. Many research gaps need to be filled before we have a better understanding of the efficacy and broader public health impact of HPV vaccination in adult women.

Population-based utility scores for HPV infection and oropharyngeal squamous cell carcinoma among Indigenous Australians

BACKGROUND

Oropharyngeal squamous cell carcinoma (OPSCC) is associated with high mortality. Human papillomavirus (HPV) infection is a significant risk factor for OPSCC. Utilities are fundamental values representing the strength of individuals' preferences for specific health-related outcomes. Our study aim was to work in partnership with Indigenous communities in South Australia to develop, pilot test and estimate utility scores for health states related to HPV, HPV vaccination, precursor OPSCC and its treatment, and early stage OPSCC among Indigenous Australians.

METHODS

Development and pilot testing of hypothetical HPV and OPSCC health states, specifically through the lens of being Indigenous Australian, was conducted with an Indigenous Reference Group. Six health states were decided upon, with utility scores calculated using a two-stage standard gamble approach among a large convenience sample of Indigenous Australians aged 18+ years residing in South Australia. The rank, percentage of perfect health and utility score of each health state was summarised using means, and medians at 12 months and lifetime duration. Potential differences by age, sex and residential location were assessed using the Wilcox Rank Sum test.

RESULTS

Data from 1011 participants was obtained. The mean utility scores decreased with increasing severity of health states, ranging from 0.91-0.92 in 'screened, cytology normal, HPV vaccination' and 'screened, HPV positive, endoscopy normal', to less than 0.90 (ranging from 0.87-0.88) in lower grade conditions (oral warts and oral intraepithelial neoplasia) and less than 0.80 (ranging from 0.75-0.79) in 'early stage throat cancer'. Higher utility scores were observed for 'screened, cytology normal and HPV vaccination' among younger participants (18-40 years), for 'early stage invasive throat cancer' among females, and for 'oral intraepithelial neoplasia' and 'early stage invasive throat cancer' among metropolitan-dwelling participants.

CONCLUSION

Among a large sample of Indigenous Australians, utility for oral HPV infection and OPSCC decreased with severity of health states. Older participants, as well as males and those residing in non-metropolitan locations, had decreased utility for high-grade cytology and early invasive cancer states. Our findings are an important contribution to cost-utility and disease prevention strategies that seek to inform policies around reducing HPV infection and OPSCC among all Australians.

Public health impact and cost-effectiveness of catch-up 9-valent HPV vaccination of individuals through age 45 years in the United States

The Advisory Committee on Immunization Practices (ACIP) recommended catch-up 9-valent Human Papillomavirus (HPV) vaccination through age 26 years, and shared clinical decision-making for adults aged 27-45 years, compared with catch-up through age 26 years and 21 years for females and males, respectively (status quo; pre-June-2019 recommendations). This study assessed the public health impact and cost-effectiveness of expanded catch-up vaccination through age 45 years (expanded catch-up) compared with status quo. We used an HPV dynamic transmission infection and disease model to assess disease outcomes and incremental cost-effectiveness ratio (ICER) of expanded catch-up compared with status quo. Costs (2018 USD), calculated from a healthcare sector perspective, and quality-adjusted life years (QALY) were discounted at 3% annually. Historical vaccination coverage was estimated using NIS-TEEN survey data (NHANES data for sensitivity analysis). Alternative scenario analyses included restricting upper age of expanded catch-up through 26 years (June-2019 ACIP recommendation), 29 years, and further 5-year increments. Our results show expanded catch-up vaccination would prevent additional 37,856 cancers, 314,468 cervical intraepithelial neoplasia-2/3s, 1,743,461 genital warts, and 10,698 deaths compared with status quo over 100 years at cost of $141,000/QALY. With NHANES coverage, the ICER was $96,000/QALY. The June-2019 ACIP recommendation also provided public health benefits with an ICER of $117,000/QALY, compared with status quo. The ICER for expanded vaccination through age 34 years was $107,000/QALY. Expanding catch-up vaccination program through age 45 years-old in the US is expected to provide public health benefits, and cost-effectiveness improves with expanding catch-up through age 34.

Cervical screening during the COVID-19 pandemic: optimising recovery strategies

Disruptions to cancer screening services have been experienced in most settings as a consequence of the COVID-19 pandemic. Ideally, programmes would resolve backlogs by temporarily expanding capacity; however, in practice, this is often not possible. We aim to inform the deliberations of decision makers in high-income settings regarding their cervical cancer screening policy response. We caution against performance measures that rely solely on restoring testing volumes to pre-pandemic levels because they will be less effective at mitigating excess cancer diagnoses than will targeted measures. These measures might exacerbate pre-existing inequalities in accessing cervical screening by disregarding the risk profile of the individuals attending. Modelling of cervical screening outcomes before and during the pandemic supports risk-based strategies as the most effective way for screening services to recover. The degree to which screening is organised will determine the feasibility of deploying some risk-based strategies, but implementation of age-based risk stratification should be universally feasible.

Importance of Lifetime Sexual History on the Prevalence of Genital Human Papillomavirus (HPV) Among Unvaccinated Adults in the National Health and Nutrition Examination Surveys: Implications for Adult HPV Vaccination

BACKGROUND

Although the United States Food and Drug Administration recently approved the human papillomavirus (HPV) vaccine for individuals aged 27-45 years, the Centers for Disease Control and Prevention did not change its guidelines for routine HPV vaccination. Since recommendations for adult vaccination emphasize shared clinical decision-making based on risk of new infections, we examined the relationship between HPV prevalence and sexual behavior.

METHODS

This study was conducted among 5093 HPV-unvaccinated, sexually experienced adults aged 18-59 years in the National Health and Nutrition Examination Surveys (2013-2016). For each sex and age group, adjusted prevalences of 9-valent vaccine-specific, high-risk, and any HPV infection were estimated by number of lifetime sexual partners (LTSPs) using logistic regression. An analysis restricted to persons who did not have a new sexual partner in the past year (ie, removing those at highest risk of newly acquired HPV) was also conducted.

RESULTS

In each age group, genital HPV prevalence was higher among persons with >5 LTSPs compared with 1-5 LTSPs in both males and females. There were only slight reductions in HPV prevalence after removing participants who reported a new sexual partner in the past year. For example, among females aged 27-45 years with >5 LTSPs, the adjusted prevalence of 9-valent vaccine-type HPV infection was 13.4% (95% confidence interval [CI], 9.9%-17.0%) in the full population compared to 12.1% (95% CI, 8.8%-15.4%) among those with no new sexual partners.

CONCLUSIONS

Prevalent HPV infection was primarily reflective of cumulative exposures over time (higher LTSPs). New exposures had limited impact, emphasizing the need to consider sexual history in the decision-making process for adult HPV vaccination.

The Estimated Direct Lifetime Medical Costs of Sexually Transmitted Infections Acquired in the United States in 2018

BACKGROUND

We estimated the lifetime medical costs attributable to sexually transmitted infections (STIs) acquired in 2018, including sexually acquired human immunodeficiency virus (HIV).

METHODS

We estimated the lifetime medical costs of infections acquired in 2018 in the United States for 8 STIs: chlamydia, gonorrhea, trichomoniasis, syphilis, genital herpes, human papillomavirus (HPV), hepatitis B, and HIV. We limited our analysis to lifetime medical costs incurred for treatment of STIs and for treatment of related sequelae; we did not include other costs, such as STI prevention. For each STI, except HPV, we calculated the lifetime medical cost by multiplying the estimated number of incident infections in 2018 by the estimated lifetime cost per infection. For HPV, we calculated the lifetime cost based on the projected lifetime incidence of health outcomes attributed to HPV infections acquired in 2018. Future costs were discounted at 3% annually.

RESULTS

Incident STIs in 2018 imposed an estimated $15.9 billion (25th-75th percentile: $14.9-16.9 billion) in discounted, lifetime direct medical costs (2019 US dollars). Most of this cost was due to sexually acquired HIV ($13.7 billion) and HPV ($0.8 billion). STIs in women accounted for about one fourth of the cost of incident STIs when including HIV, but about three fourths when excluding HIV. STIs among 15- to 24-year-olds accounted for $4.2 billion (26%) of the cost of incident STIs.

CONCLUSIONS

Incident STIs continue to impose a considerable lifetime medical cost burden in the United States. These results can inform health economic analyses to promote the use of cost-effective STI prevention interventions to reduce this burden.

Estimated Prevalence and Incidence of Disease-Associated Human Papillomavirus Types Among 15- to 59-Year-Olds in the United States

INTRODUCTION

Human papillomavirus (HPV) can cause anogenital warts and several types of cancer, including cervical cancers and precancers. We estimated the prevalence, incidence, and number of persons with prevalent and incident HPV infections in the United States in 2018.

METHODS

Prevalence and incidence were estimated for infections with any HPV (any of 37 types detected using Linear Array) and disease-associated HPV, 2 types that cause anogenital warts plus 14 types detected by tests used for cervical cancer screening (HPV 6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68). We used the 2013-2016 National Health and Nutrition Examination Survey to estimate prevalence among 15- to 59-year-olds, overall and by sex. Incidences in 2018 were estimated per 10,000 persons using an individual-based transmission-dynamic type-specific model calibrated to US data. We estimated number of infected persons by applying prevalences and incidences to 2018 US population estimates.

RESULTS

Prevalence of infection with any HPV was 40.0% overall, 41.8% in men, and 38.4% in women; prevalence of infection with disease-associated HPV was 24.2% in men and 19.9% in women. An estimated 23.4 and 19.2 million men and women had a disease-associated HPV type infection in 2018. Incidences of any and disease-associated HPV infection were 1222 and 672 per 10,000 persons; incidence of disease-associated HPV infection was 708 per 10,000 men and 636 per 10,000 women. An estimated 6.9 and 6.1 million men and women had an incident infection with a disease-associated HPV type in 2018.

CONCLUSIONS

We document a high HPV burden of infection in the United States in 2018, with 42 million persons infected with disease-associated HPV and 13 million persons acquiring a new infection. Although most infections clear, some disease-associated HPV type infections progress to disease. The HPV burden highlights the need for continued monitoring of HPV-associated cancers, cervical cancer screening, and HPV vaccination to track and prevent disease.

Human papillomavirus vaccination for adults aged 30 to 45 years in the United States: A cost-effectiveness analysis

BACKGROUND

A nonavalent human papillomavirus (HPV) vaccine has been licensed for use in women and men up to age 45 years in the United States. The cost-effectiveness of HPV vaccination for women and men aged 30 to 45 years in the context of cervical cancer screening practice was evaluated to inform national guidelines.

METHODS AND FINDINGS

We utilized 2 independent HPV microsimulation models to evaluate the cost-effectiveness of extending the upper age limit of HPV vaccination in women (from age 26 years) and men (from age 21 years) up to age 30, 35, 40, or 45 years. The models were empirically calibrated to reflect the burden of HPV and related cancers in the US population and used standardized inputs regarding historical and future vaccination uptake, vaccine efficacy, cervical cancer screening, and costs. Disease outcomes included cervical, anal, oropharyngeal, vulvar, vaginal, and penile cancers, as well as genital warts. Both models projected higher costs and greater health benefits as the upper age limit of HPV vaccination increased. Strategies of vaccinating females and males up to ages 30, 35, and 40 years were found to be less cost-effective than vaccinating up to age 45 years, which had an incremental cost-effectiveness ratio (ICER) greater than a commonly accepted upper threshold of $200,000 per quality-adjusted life year (QALY) gained. When including all HPV-related outcomes, the ICER for vaccinating up to age 45 years ranged from $315,700 to $440,600 per QALY gained. Assumptions regarding cervical screening compliance, vaccine costs, and the natural history of noncervical HPV-related cancers had major impacts on the cost-effectiveness of the vaccination strategies. Key limitations of the study were related to uncertainties in the data used to inform the models, including the timing of vaccine impact on noncervical cancers and vaccine efficacy at older ages.

CONCLUSIONS

Our results from 2 independent models suggest that HPV vaccination for adult women and men aged 30 to 45 years is unlikely to represent good value for money in the US.