Strategies for the introduction of human papillomavirus vaccination: modelling the optimum age- and sex-specific pattern of vaccination in Finland

Abnormal cervical cancer screening results among US Veteran and non-Veteran participants in the National Health Interview Survey (NHIS)

Female Veterans report cervical cancer risk factors at higher rates than non-Veterans. Using data from the National Health Interview Survey (NHIS), we tested whether Veterans with a recent cervical cancer screening test were more likely than non-Veterans to have received an abnormal result. NHIS is a population-based cross-sectional household survey with a stratified, multistage sampling design. We pooled screening data from 2010, 2015, and 2018, and restricted the sample to female participants without a hysterectomy who had a cervical cancer screening test in the prior 3 years. The primary outcome was self-reported abnormal result on a Pap and/or HPV test in the prior 3 years. Our main predictor was Veteran status. We used survey-weighted multivariable logistic regression to estimate odds of an abnormal screening result in the prior 3 years as a function of Veteran status, controlling first for age and survey year, then adding sociodemographic and health factors in subsequent models. The sample included 380 Veterans and 25,102 non-Veterans (weighted total population 104.9 million). Overall, 19.0% of Veterans and 13.7% of non-Veterans reported an abnormal cervical cancer screening test result in the prior 3 years (unadjusted p = 0.03). In the adjusted regression model, the previously observed association between Veteran status and abnormal screening result was explained by differences in sociodemographic and health factors between Veterans and non-Veterans (aOR 1.21, 95%CI 0.78-1.87). Nearly 1 in 5 Veterans with a recent cervical cancer screening test received an abnormal result. Clinicians should address modifiable risk factors and provide evidence-based follow-up for abnormal results.

Assessing the epidemiological impact on cervical cancer of switching from 4-valent to 9-valent HPV vaccine within a gender-neutral vaccination programme in Switzerland

BACKGROUND

An infection with high-risk human papillomavirus (HPV) is the obligatory aetiological factor for the development of cervical cancer. In Switzerland, the prevention strategy for cervical cancer is based on primary prevention via HPV vaccination and secondary prevention with an opportunistic screening programme for precancerous lesions. Vaccination is recommended to 11-26 years old male and female persons. The objective of the study was to assess the epidemiological impact on cervical cancer of switching from the currently implemented programme with the 4-valent vaccine to the 9-valent vaccine, in an 11-26 years old gender-neutral vaccination programme in Switzerland.

METHODS

A previously validated dynamic transmission model of HPV infections was adapted and calibrated to the Swiss setting assuming an 80% coverage rate in HPV-vaccination and lifelong vaccine type-specific protection. A gender-neutral vaccination programme (males and females) for 11-26 years old with a 9-valent HPV vaccine was compared with the current 11-26 years old gender-neutral 4-valent vaccination programme. Sensitivity analyses were conducted in order to test the impact of lower vaccination coverage rates and a shorter duration of protection on the model outcomes.

RESULTS

In Switzerland, a 9-valent gender-neutral vaccination programme would result in an additional prevention of 2979 cervical cancer cases, 13,862 CIN3 and 15,000 CIN2 cases, compared with the 4-valent gender-neutral vaccination programme over 100 years. These additional disease cases avoided would correspond to a 24, 36 and 48% cumulative incidence decrease in cervical cancer, CIN3 and CIN2 cases, respectively. It would also prevent additional 741 cervical cancer-related deaths over 100 years. A substantial additional reduction in cervical cancer and precancerous lesions burden is still observed when varying the vaccination coverage rate from 30 to 60% or reducing the duration of protection from lifelong to 20 years.

CONCLUSIONS

The switch to the 9-valent vaccine in Switzerland to prevent cervical diseases showed an important contribution in terms of public health impact compared with the 4-valent vaccine in an 11-26 years old gender-neutral population, even with very conservative assumptions such as low coverage rates or low duration of protection and limiting analysis to only cervical disease.

Assessing the cost-effectiveness of HPV vaccination strategies for adolescent girls and boys in the UK

BACKGROUND

Human papillomavirus (HPV) is the most widespread sexually transmitted infection worldwide. It causes several health consequences, in particular accounting for the majority of cervical cancer cases in women. In the United Kingdom, a vaccination campaign targeting 12-year-old girls started in 2008; this campaign has been successful, with high uptake and reduced HPV prevalence observed in vaccinated cohorts. Recently, attention has focused on vaccinating both sexes, due to HPV-related diseases in males (particularly for high-risk men who have sex with men) and an equity argument over equalising levels of protection.

METHODS

We constructed an epidemiological model for HPV transmission in the UK, accounting for nine of the most common HPV strains. We complemented this with an economic model to determine the likely health outcomes (healthcare costs and quality-adjusted life years) for individuals from the epidemiological model. We then tested vaccination with the three HPV vaccines currently available, vaccinating either girls alone or both sexes. For each strategy we calculated the threshold price per vaccine dose, i.e. the maximum amount paid for the added health benefits of vaccination to be worth the cost of each vaccine dose. We calculated results at 3.5% discounting, and also 1.5%, to consider the long-term health effects of HPV infection.

RESULTS

At 3.5% discounting, continuing to vaccinate girls remains highly cost-effective compared to halting vaccination, with threshold dose prices of £56-£108. Vaccination of girls and boys is less cost-effective (£25-£53). Compared to vaccinating girls only, adding boys to the programme is not cost-effective, with negative threshold prices (-£6 to -£3) due to the costs of administration. All threshold prices increase when using 1.5% discounting, and adding boys becomes cost-effective (£36-£47). These results are contingent on the UK's high vaccine uptake; for lower uptake rates, adding boys (at the same uptake rate) becomes more cost effective.

CONCLUSIONS

Vaccinating girls is extremely cost-effective compared with no vaccination, vaccinating both sexes is less so. Adding boys to an already successful girls-only programme has a low cost-effectiveness, as males have high protection through herd immunity. If future health effects are weighted more heavily, threshold prices increase and vaccination becomes cost-effective.

The Cost-Effectiveness of Quadrivalent Human Papillomavirus Vaccination in Indonesia

Objective: National cervical cancer prevention program has been initiated in Indonesia since April 2015 and the ministry of health has started efforts to integrate the HPV Vaccine in the national immunization program since Q4 2015. Thus, it becomes important to analyze the cost-effectiveness of HPV vaccine. The objective of this model is to examine the potential long-term epidemiologic and economic impact of quadrivalent HPV(qHPV;6/11/16/18) vaccination program in Indonesia. Methods: A previously validated transmission dynamic model was used to estimate the long-term epidemiologic and economic consequences of quadrivalent HPV vaccination by comparing cost-effectiveness of 2 dose qHPV vaccination strategy for girls 11-12 years old (with or without catch up; catch up dose for 12–26 years) versus Screening Only (Pap Smear) for reducing cost related to HPV type 6,11,16,18 (cervical cancer, CIN 1, CIN 2/3, and genital warts). Costs of an HPV disease episode-of-care (diagnosis and treatment) were calculated for base case analysis using local Indonesian cost. Result: 2-dose qHPV vaccination strategies without catch up reduce the overall incidence of HPV 16/18–related cervical cancer relative to screening by 54.4% over the 100 year following vaccine introduction. Likewise, vaccination strategies reduce the incidence of HPV type 16/18 CIN 2/3, CIN 1 by 69.1% and 71.8% respectively, also reducing HPV type 6/11 CIN 1, genital warts in female, genital warts in male by 82.9%,84.2%,82.1% respectively, at this time point. From total reduction of health care cost, 67.1% attributable for diseases caused by HPV type 16/18 and 32.9% attributable for diseases caused by HPV type 6/11. Without catch up, cost/QALY would be $450/year. However catch-up strategy is more cost effective versus vaccinates 12-year-old girls only; with cost/QALYs would be $390/year. Conclusion: HPV 6/11/16/18 vaccination of females in Indonesia are 1) substantially reduce genital warts, CIN, and cervical cancer; 2) improve quality of life, and 3) with the Indonesia GDP of USD 3,531.80 in 2014 , Cost/QALYs result with or without catch up is considered very cost-effective when implemented; however with catch up, the cost/QALY can be better.

Surveillance of Vaccination Coverage among Adult Populations - United States, 2015

PROBLEM/CONDITION

Overall, the prevalence of illness attributable to vaccine-preventable diseases is greater among adults than among children. Adults are recommended to receive vaccinations based on their age, underlying medical conditions, lifestyle, prior vaccinations, and other considerations. Updated vaccination recommendations from CDC are published annually in the U.S. Adult Immunization Schedule. Despite longstanding recommendations for use of many vaccines, vaccination coverage among U.S. adults is low.

PERIOD COVERED

August 2014-June 2015 (for influenza vaccination) and January-December 2015 (for pneumococcal, tetanus and diphtheria [Td] and tetanus and diphtheria with acellular pertussis [Tdap], hepatitis A, hepatitis B, herpes zoster, and human papillomavirus [HPV] vaccination).

DESCRIPTION OF SYSTEM

The National Health Interview Survey (NHIS) is a continuous, cross-sectional national household survey of the noninstitutionalized U.S. civilian population. In-person interviews are conducted throughout the year in a probability sample of households, and NHIS data are compiled and released annually. The survey objective is to monitor the health of the U.S. population and provide estimates of health indicators, health care use and access, and health-related behaviors.

RESULTS

Compared with data from the 2014 NHIS, increases in vaccination coverage occurred for influenza vaccine among adults aged ≥19 years (a 1.6 percentage point increase compared with the 2013-14 season to 44.8%), pneumococcal vaccine among adults aged 19-64 years at increased risk for pneumococcal disease (a 2.8 percentage point increase to 23.0%), Tdap vaccine among adults aged ≥19 years and adults aged 19-64 years (a 3.1 percentage point and 3.3 percentage point increase to 23.1% and to 24.7%, respectively), herpes zoster vaccine among adults aged ≥60 years and adults aged ≥65 years (a 2.7 percentage point and 3.2 percentage point increase to 30.6% and to 34.2%, respectively), and hepatitis B vaccine among health care personnel (HCP) aged ≥19 years (a 4.1 percentage point increase to 64.7%). Herpes zoster vaccination coverage in 2015 met the Healthy People 2020 target of 30%. Aside from these modest improvements, vaccination coverage among adults in 2015 was similar to estimates from 2014. Racial/ethnic differences in coverage persisted for all seven vaccines, with higher coverage generally for whites compared with most other groups. Adults without health insurance reported receipt of influenza vaccine (all age groups), pneumococcal vaccine (adults aged 19-64 years at increased risk), Td vaccine (adults aged ≥19 years, 19-64 years, and 50-64 years), Tdap vaccine (adults aged ≥19 years and 19-64 years), hepatitis A vaccine (adults aged ≥19 years overall and among travelers), hepatitis B vaccine (adults aged ≥19 years, 19-49 years, and among travelers), herpes zoster vaccine (adults aged ≥60 years), and HPV vaccine (males and females aged 19-26 years) less often than those with health insurance. Adults who reported having a usual place for health care generally reported receipt of recommended vaccinations more often than those who did not have such a place, regardless of whether they had health insurance. Vaccination coverage was higher among adults reporting one or more physician contacts in the past year compared with those who had not visited a physician in the past year, regardless of whether they had health insurance. Even among adults who had health insurance and ≥10 physician contacts within the past year, depending on the vaccine, 18.2%-85.6% reported not having received vaccinations that were recommended either for all persons or for those with specific indications. Overall, vaccination coverage among U.S.-born adults was higher than that among foreign-born adults, with few exceptions (influenza vaccination [adults aged 19-49 years and 50-64 years], hepatitis A vaccination [adults aged ≥19 years], and hepatitis B vaccination [adults aged ≥19 years with diabetes or chronic liver conditions]).

INTERPRETATION

Coverage for all vaccines for adults remained low but modest gains occurred in vaccination coverage for influenza (adults aged ≥19 years), pneumococcal (adults aged 19-64 years with increased risk), Tdap (adults aged ≥19 years and adults aged 19-64 years), herpes zoster (adults aged ≥60 years and ≥65 years), and hepatitis B (HCP aged ≥19 years); coverage for other vaccines and groups with vaccination indications did not improve. The 30% Healthy People 2020 target for herpes zoster vaccination was met. Racial/ethnic disparities persisted for routinely recommended adult vaccines. Missed opportunities to vaccinate remained. Although having health insurance coverage and a usual place for health care were associated with higher vaccination coverage, these factors alone were not associated with optimal adult vaccination coverage. HPV vaccination coverage for males and females has increased since CDC recommended vaccination to prevent cancers caused by HPV, but many adolescents and young adults remained unvaccinated.

PUBLIC HEALTH ACTIONS

Assessing factors associated with low coverage rates and disparities in vaccination is important for implementing strategies to improve vaccination coverage. Evidence-based practices that have been demonstrated to improve vaccination coverage should be used. These practices include assessment of patients' vaccination indications by health care providers and routine recommendation and offer of needed vaccines to adults, implementation of reminder-recall systems, use of standing-order programs for vaccination, and assessment of practice-level vaccination rates with feedback to staff members. For vaccination coverage to be improved among those who reported lower coverage rates of recommended adult vaccines, efforts also are needed to identify adults who do not have a regular provider or insurance and who report fewer health care visits.

Identification of sex-associated network patterns in Vaccine-Adverse Event Association Network in VAERS

Background

Vaccines are one of the most important public health successes in last century. Besides effectiveness in reducing the morbidity and mortality from many infectious diseases, a successful vaccine program also requires a rigorous assessment on their safety. Due to the limitations of adverse event (AE) data from clinical trials and post-approval surveillance systems, novel computational approaches are needed to organize, visualize, and analyze such high-dimensional complex data.

Results

In this paper, we proposed a network-based approach to investigate the vaccine-AE association network from the Vaccine AE Reporting System (VAERS) data. Statistical summary was calculated using the VAERS raw data and represented in the Resource Description Framework (RDF). The RDF graph was leveraged for network analysis. Specifically, we compared network properties of (1) vaccine - adverse event association network based on reports collected over a 23 year period as well as each year; and (2) sex-specific vaccine-adverse event association network. We observed that (1) network diameter and average path length don’t change dramatically over a 23-year period, while the average node degree of these networks changes due to the different number of reports during different periods of time; (2) vaccine - adverse event associations derived from different sexes show sex-associated patterns in sex-specific vaccine-AE association networks.

Conclusions

We have developed a network-based approach to investigate the vaccine-AE association network from the VAERS data. To our knowledge, this is the first time that a network-based approach was used to identify sex-specific association patterns in a spontaneous reporting system database. Due to unique limitations of such passive surveillance systems, our proposed network-based approaches have the potential to summarize and analyze the associations in passive surveillance systems by (1) identifying nodes of importance, irrespective of whether they are disproportionally reported; (2) providing guidance on sex-specific recommendations in personalized vaccinology.

Electronic supplementary material

The online version of this article (doi:10.1186/s13326-015-0032-2) contains supplementary material, which is available to authorized users.

Efficacy of human papillomavirus 16 and 18 (HPV-16/18) AS04-adjuvanted vaccine against cervical infection and precancer in young women: final event-driven analysis of the randomized, double-blind PATRICIA trial

We report final event-driven analysis data on the immunogenicity and efficacy of the human papillomavirus 16 and 18 ((HPV-16/18) AS04-adjuvanted vaccine in young women aged 15 to 25 years from the PApilloma TRIal against Cancer In young Adults (PATRICIA). The total vaccinated cohort (TVC) included all randomized participants who received at least one vaccine dose (vaccine, n = 9,319; control, n = 9,325) at months 0, 1, and/or 6. The TVC-naive (vaccine, n = 5,822; control, n = 5,819) had no evidence of high-risk HPV infection at baseline, approximating adolescent girls targeted by most HPV vaccination programs. Mean follow-up was approximately 39 months after the first vaccine dose in each cohort. At baseline, 26% of women in the TVC had evidence of past and/or current HPV-16/18 infection. HPV-16 and HPV-18 antibody titers postvaccination tended to be higher among 15- to 17-year-olds than among 18- to 25-year-olds. In the TVC, vaccine efficacy (VE) against cervical intraepithelial neoplasia grade 1 or greater (CIN1+), CIN2+, and CIN3+ associated with HPV-16/18 was 55.5% (96.1% confidence interval [CI], 43.2, 65.3), 52.8% (37.5, 64.7), and 33.6% (-1.1, 56.9). VE against CIN1+, CIN2+, and CIN3+ irrespective of HPV DNA was 21.7% (10.7, 31.4), 30.4% (16.4, 42.1), and 33.4% (9.1, 51.5) and was consistently significant only in 15- to 17-year-old women (27.4% [10.8, 40.9], 41.8% [22.3, 56.7], and 55.8% [19.2, 76.9]). In the TVC-naive, VE against CIN1+, CIN2+, and CIN3+ associated with HPV-16/18 was 96.5% (89.0, 99.4), 98.4% (90.4, 100), and 100% (64.7, 100), and irrespective of HPV DNA it was 50.1% (35.9, 61.4), 70.2% (54.7, 80.9), and 87.0% (54.9, 97.7). VE against 12-month persistent infection with HPV-16/18 was 89.9% (84.0, 94.0), and that against HPV-31/33/45/51 was 49.0% (34.7, 60.3). In conclusion, vaccinating adolescents before sexual debut has a substantial impact on the overall incidence of high-grade cervical abnormalities, and catch-up vaccination up to 18 years of age is most likely effective. (This study has been registered at ClinicalTrials.gov under registration no. NCT001226810.).

Proteção individual versus proteção coletiva: análise bioética do programa nacional de vacinação infantil em massa

A vacinação é considerada como uma das políticas de saúde pública mais efetivas e de menor custo-benefício, utilizada no controle e na prevenção de doenças. Mas é também considerada uma das técnicas biomédicas mais polêmicas e controversas, o que torna difícil evitar uma abordagem ética, principalmente quando a vacinação é utilizada de forma compulsória em toda a população. Com efeito, visto que as vacinas não são totalmente seguras e eficazes, há um conflito ético entre o interesse individual e o coletivo, pois as crianças carregam de fato o ônus da vacinação em benefício da saúde pública quando são acometidas com reações adversas graves e que ficam alheias aos cuidados que deveriam ser oferecidos pelo Poder Público. O objetivo deste artigo foi demonstrar que as ferramentas da bioética são relevantes nesta discussão para analisar e compreender criticamente estes conflitos, fornecendo argumentos cogentes para orientar a elaboração de biopolíticas que considerem não apenas, com rigor, a prevenção, mas, também, a responsabilidade solidária de todos como fundamento para uma proteção que seja tanto individual como coletiva.

Efficacy, safety, and immunogenicity of the human papillomavirus 16/18 AS04-adjuvanted vaccine in women older than 25 years: 4-year interim follow-up of the phase 3, double-blind, randomised controlled VIVIANE study

BACKGROUND

Although adolescent girls are the main population for prophylactic human papillomavirus (HPV) vaccines, adult women who remain at risk of cervical cancer can also be vaccinated. We report data from the interim analysis of the ongoing VIVIANE study, the aim of which is to assess the efficacy, safety, and immunogenicity of the HPV 16/18 AS04-adjuvanted vaccine in adult women.

METHODS

In this phase 3, multinational, double-blind, randomised controlled trial, we randomly assigned healthy women older than 25 years to the HPV 16/18 vaccine or control (1:1), via an internet-based system with an algorithm process that accounted for region, age stratum, baseline HPV DNA status, HPV 16/18 serostatus, and cytology. Enrolment was age-stratified, with about 45% of participants in each of the 26-35 and 36-45 years age strata and 10% in the 46 years and older stratum. Up to 15% of women in each age stratum could have a history of HPV infection or disease. The primary endpoint was vaccine efficacy against 6-month persistent infection or cervical intraepithelial neoplasia grade 1 or higher (CIN1+) associated with HPV 16/18. The primary analysis was done in the according-to-protocol cohort for efficacy, which consists of women who received all three vaccine or control doses, had negative or low-grade cytology at baseline, and had no history of HPV disease. Secondary analyses included vaccine efficacy against non-vaccine oncogenic HPV types. Mean follow-up time was 40·3 months. This study is registered with ClinicalTrials.gov, number NCT00294047.

FINDINGS

The first participant was enrolled on Feb 16, 2006, and the last study visit for the present analysis took place on Dec 10, 2010; 5752 women were included in the total vaccinated cohort (n=2881 vaccine, n=2871 control), and 4505 in the according-to-protocol cohort for efficacy (n=2264 vaccine, n=2241 control). Vaccine efficacy against HPV 16/18-related 6-month persistent infection or CIN1+ was significant in all age groups combined (81·1%, 97·7% CI 52·1-94·0), in the 26-35 years age group (83·5%, 45·0-96·8), and in the 36-45 years age group (77·2%, 2·8-96·9); no cases were seen in women aged 46 years and older. Vaccine efficacy against atypical squamous cells of undetermined significance or greater associated with HPV 16/18 was also significant. We also noted significant cross-protective vaccine efficacy against 6-month persistent infection with HPV 31 (79·1%, 97·7% CI 27·6-95·9) and HPV 45 (76·9%, 18·5-95·6]) Serious adverse events occurred in 285 (10%) of 2881 women in the vaccine group and 267 (9%) of 2871 in the control group; five (<1%) and eight (<1%) of these events, respectively, were believed to be related to vaccination.

INTERPRETATION

In women older than 25 years, the HPV 16/18 vaccine is efficacious against infections and cervical abnormalities associated with the vaccine types, as well as infections with the non-vaccine HPV types 31 and 45.

FUNDING

GlaxoSmithKline Biologicals SA.

An updated natural history model of cervical cancer: derivation of model parameters

Mathematical models of cervical cancer have been widely used to evaluate the comparative effectiveness and cost-effectiveness of preventive strategies. Major advances in the understanding of cervical carcinogenesis motivate the creation of a new disease paradigm in such models. To keep pace with the most recent evidence, we updated a previously developed microsimulation model of human papillomavirus (HPV) infection and cervical cancer to reflect 1) a shift towards health states based on HPV rather than poorly reproducible histological diagnoses and 2) HPV clearance and progression to precancer as a function of infection duration and genotype, as derived from the control arm of the Costa Rica Vaccine Trial (2004-2010). The model was calibrated leveraging empirical data from the New Mexico Surveillance, Epidemiology, and End Results Registry (1980-1999) and a state-of-the-art cervical cancer screening registry in New Mexico (2007-2009). The calibrated model had good correspondence with data on genotype- and age-specific HPV prevalence, genotype frequency in precancer and cancer, and age-specific cancer incidence. We present this model in response to a call for new natural history models of cervical cancer intended for decision analysis and economic evaluation at a time when global cervical cancer prevention policy continues to evolve and evidence of the long-term health effects of cervical interventions remains critical.

The theoretical impact and cost-effectiveness of vaccines that protect against sexually transmitted infections and disease

Sexually transmitted diseases, a source of widespread morbidity and sometimes mortality, are caused by a diverse group of infections with a common route of transmission. Existing vaccines against hepatitis B virus (HBV) and human papilloma virus 16, 18, 6 and 11 are highly efficacious and cost effective. In reviewing the potential role for other vaccines against sexually transmitted infections (STIs) a series of questions needs to be addressed about the burden of disease, the potential characteristics of a new vaccine, and the impact of other interventions. These questions can be viewed in the light of the population dynamics of sexually transmitted infections as a group and how a vaccine can impact these dynamics. Mathematical models show the potential for substantial impact, especially if vaccines are widely used. To better make the case for sexually transmitted infection vaccines we need better data and analyses of the burden of disease, especially severe disease. However, cost effectiveness analyses using a wide range of assumptions show that STI vaccines would be cost effective and their development a worthwhile investment.

Is expanding HPV vaccination programs to include school-aged boys likely to be value-for-money: a cost-utility analysis in a country with an existing school-girl program

Background

Similar to many developed countries, vaccination against human papillomavirus (HPV) is provided only to girls in New Zealand and coverage is relatively low (47% in school-aged girls for dose 3). Some jurisdictions have already extended HPV vaccination to school-aged boys. Thus, exploration of the cost-utility of adding boys’ vaccination is relevant. We modeled the incremental health gain and costs for extending the current girls-only program to boys, intensifying the current girls-only program to achieve 73% coverage, and extension of the intensive program to boys.

Methods

A Markov macro-simulation model, which accounted for herd immunity, was developed for an annual cohort of 12-year-olds in 2011 and included the future health states of: cervical cancer, pre-cancer (CIN I to III), genital warts, and three other HPV-related cancers. In each state, health sector costs, including additional health costs from extra life, and quality-adjusted life-years (QALYs) were accumulated. The model included New Zealand data on cancer incidence and survival, and other cause mortality (all by sex, age, ethnicity and deprivation).

Results

At an assumed local willingness-to-pay threshold of US$29,600, vaccination of 12-year-old boys to achieve the current coverage for girls would not be cost-effective, at US$61,400/QALY gained (95% UI $29,700 to $112,000; OECD purchasing power parities) compared to the current girls-only program, with an assumed vaccine cost of US$59 (NZ$113). This was dominated though by the intensified girls-only program; US$17,400/QALY gained (95% UI: dominant to $46,100). Adding boys to this intensified program was also not cost-effective; US$128,000/QALY gained, 95% UI: $61,900 to $247,000).

Vaccination of boys was not found to be cost-effective, even for additional scenarios with very low vaccine or program administration costs – only when combined vaccine and administration costs were NZ$125 or lower per dose was vaccination of boys cost-effective.

Conclusions

These results suggest that adding boys to the girls-only HPV vaccination program in New Zealand is highly unlikely to be cost-effective. In order for vaccination of males to become cost-effective in New Zealand, vaccine would need to be supplied at very low prices and administration costs would need to be minimised.

Prevention of HPV-related cancers in Norway: cost-effectiveness of expanding the HPV vaccination program to include pre-adolescent boys

Background

Increasingly, countries have introduced female vaccination against human papillomavirus (HPV), causally linked to several cancers and genital warts, but few have recommended vaccination of boys. Declining vaccine prices and strong evidence of vaccine impact on reducing HPV-related conditions in both women and men prompt countries to reevaluate whether HPV vaccination of boys is warranted.

Methods

A previously-published dynamic model of HPV transmission was empirically calibrated to Norway. Reductions in the incidence of HPV, including both direct and indirect benefits, were applied to a natural history model of cervical cancer, and to incidence-based models for other non-cervical HPV-related diseases. We calculated the health outcomes and costs of the different HPV-related conditions under a gender-neutral vaccination program compared to a female-only program.

Results

Vaccine price had a decisive impact on results. For example, assuming 71% coverage, high vaccine efficacy and a reasonable vaccine tender price of $75 per dose, we found vaccinating both girls and boys fell below a commonly cited cost-effectiveness threshold in Norway ($83,000/quality-adjusted life year (QALY) gained) when including vaccine benefit for all HPV-related diseases. However, at the current market price, including boys would not be considered ‘good value for money.’ For settings with a lower cost-effectiveness threshold ($30,000/QALY), it would not be considered cost-effective to expand the current program to include boys, unless the vaccine price was less than $36/dose. Increasing vaccination coverage to 90% among girls was more effective and less costly than the benefits achieved by vaccinating both genders with 71% coverage.

Conclusions

At the anticipated tender price, expanding the HPV vaccination program to boys may be cost-effective and may warrant a change in the current female-only vaccination policy in Norway. However, increasing coverage in girls is uniformly more effective and cost-effective than expanding vaccination coverage to boys and should be considered a priority.

Upscaling human papillomavirus vaccination in high-income countries: impact assessment based on transmission model

BACKGROUND

The decrease in human papillomavirus (HPV) vaccine prices may allow upscale already started vaccination programmes but the advantages of different options are unclear.

METHODS

Using a mathematical model of HPV16 and 18 transmission and data on vaccination coverage from Italy, we compared 3 options to upscale an already started programme targeting 11-year old girls (coverage 65%): a) coverage improvement (from 65% to 90%); b) addition of 11-year-old boys (coverage 65%); or c) 1-year catch-up of older girls (coverage 50%).

RESULTS

The reduction of cervical HPV16/18 infection as compared to no vaccination (i.e. effectiveness against HPV16/18) increased from 76% to 98% with coverage improvement in girls and to 90% with the addition of boys. With higher coverage in girls, HPV16/18 infection cumulative probability by age 35 decreased from 25% to 8% with a 38% increase in vaccine number. The addition of boys decreased the cumulative probability to 18% with a 100% increase in the number of vaccinees. For any coverage in girls, the number of vaccinees to prevent 1 woman from being infected by HPV16/18 by age 35 was 1.5, whereas it was 2.7 for the addition of boys. Catch-up of older girls only moved forward the vaccination effectiveness by 2-5 years.

CONCLUSIONS

Increasing vaccination coverage among girls is the most effective option for decreasing HPV16/18. If not achievable, vaccinating boys is justifiable if vaccine cost has at least halved, because this option would almost double the number of vaccinees.

Quantifying clinical HPV4 dose inefficiencies in a safety net population

PURPOSE

HPV4 is the most expensive vaccine requiring three appropriately timed doses to provide maximal efficacy against two oncogenic HPV types. The primary purpose of this study is to quantify the use of HPV4 vaccine in a safety net health care system in terms of its inefficiencies.

METHODS

A retrospective study of HPV4 dosing from 2006-2009, among females 10-26 years old who sought care in a safety net health care system was conducted to determine dose usage patterns among those at highest risk for cervical cancer. Dose descriptors abstracted from the electronic medical record (EMR) included timing and number in series as well as characteristics of the person to whom and visit at which the dose was given. Dose inefficiencies were separated into "less than three doses" and "mistimed doses" for analysis.

RESULTS

The majority (66%) of HPV4 doses administered were insufficient to induce the maximal immune response necessary for HPV infection prevention. Among on-time doses, 58% were singleton or doublet doses. Mistimed doses accounted for 19% of all doses administered with late intervals being more common than early intervals among those receiving more than one dose (9% vs. 4%, p<0.001). Third doses were mistimed twice as often as second doses (10% vs. 5%, p<0.001). Black women were more likely to have a mistimed second dose and Hispanic women more likely to have a mistimed third dose compared to white women (OR = 1.70 (95% CI: 1.11, 2.61 and 2.44 (1.19, 5.00), respectively). The HPV4-only visit type at which HPV4 was initiated was the most significant predictor of on-time doublet completion.

CONCLUSIONS

In a safety net health care system the large inefficiencies associated with HPV4 vaccination must be addressed in order to maximize our patient's cervical cancer prevention.

Predictors of three dose on-time compliance with HPV4 vaccination in a disadvantaged, underserved, safety net population in the US Midwest

BACKGROUND

HPV4 is approved as a series of three timed doses expected to result in efficacy against specific HPV infections. Completion rates in the US are quite low at the same time the structure of health care delivery is changing. The aim of this study was to determine how the patient-, clinic- and systems-level characteristics facilitate or hinder the timely completion of three HPV4 doses in both adolescent and adult female populations in a high-risk safety net population.

METHODS

This is a retrospective study in which patient-, clinic- and systems-level data are abstracted from the electronic medical record (EMR) for all females 10-26 years of age receiving at least one dose of HPV4 between July 1, 2006 and October 1, 2009.

RESULTS

Adults were more likely to complete the three dose series if they had at least one health care visit in addition to their HPV4 visit, (aOR = 1.54 (95% CI:1.10, 2.15). Adults were less likely to complete the three dose series if they received their second HPV4 dose at an acute health care, preventive care or postpartum visits compared to an HPV4-only visit (aOR = 0.31 (95% CI: 0.13, 0.72), 0.12 (0.04, 0.35), 0.30 (0.14, 0.62), respectively). Hispanic adults were less likely than whites to complete the series (aOR = 0.24 (95% CI:0.10, 0.59). 39% of adolescents who completed two doses completed the series.

CONCLUSIONS

HPV4 is more likely to be effectively administered to adults in a safety net population if multiple health care needs can be met within the health care system.

Modeling preventative strategies against human papillomavirus-related disease in developed countries

Over the last 5 years, prophylactic vaccination against human papillomavirus (HPV) in pre-adolescent females has been introduced in most developed countries, supported by modeled evaluations that have almost universally found vaccination of pre-adolescent females to be cost-effective. Studies to date suggest that vaccination of pre-adolescent males may also be cost-effective at a cost per vaccinated individual of ~US$400-500 if vaccination coverage in females cannot be increased above ~50%; but if it is possible, increasing coverage in females appears to be a better return on investment. Comparative evaluation of the quadrivalent (HPV16,18,6,11) and bivalent (HPV16,18) vaccines centers around the potential trade-off between protection against anogenital warts and vaccine-specific levels of cross-protection against infections not targeted by the vaccines. Future evaluations will also need to consider the cost-effectiveness of a next generation nonavalent vaccine designed to protect against ~90% of cervical cancers. The timing of the effect of vaccination on cervical screening programs will be country-specific and will depend on vaccination catch-up age range and coverage and the age at which screening starts. Initial evaluations suggest that if screening remains unchanged, it will be less cost-effective in vaccinated compared to unvaccinated women but, in the context of current vaccines, will remain an important prevention method. Comprehensive evaluation of new approaches to screening will need to consider the population-level effects of vaccination over time. New screening strategies of particular interest include delaying the start age of screening, increasing the screening interval and switching to primary HPV screening. Future evaluations of screening will also need to focus on the effects of disparities in screening and vaccination uptake, the potential effects of vaccination on screening participation, and the effects of imperfect compliance with screening recommendations. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.

Acceptance on the move: public reaction to shifting vaccination realities

This review examines four events related to vaccination that have occurred in recent years: (a) the ongoing recovery from the MMR/Autism scare in the UK, (b) the upgrading of the Varicella vaccine to a universal childhood vaccine, (c) the major effort of authorities to provide a vaccine for A/H1N1 influenza and its rejection by the public, and, d) the current attempts to change the HPV vaccine target from girls only to boys and girls. All of these changes have been met with shifts in the public acceptance of the relevant vaccine. These shifts are characterized not only by the number of people willing to be vaccinated, but also by the attitudes and the motives related to acceptance. Examination of the interrelationship between changes in vaccination realities, and changes in acceptance patterns suggests that today, the public has a better understanding of vaccination, is acting in a more reflexive way, and is capable of changing attitudes and behavior. All together, changes in vaccination enhance debates and dialogues about vaccines, and lead to higher awareness and more conscious acceptance.

Overall efficacy of HPV-16/18 AS04-adjuvanted vaccine against grade 3 or greater cervical intraepithelial neoplasia: 4-year end-of-study analysis of the randomised, double-blind PATRICIA trial

BACKGROUND

Cervical intraepithelial neoplasia grade 2 or greater (CIN2+) is the surrogate endpoint used in licensure trials of human papillomavirus (HPV) vaccines. Vaccine efficacy against CIN3+, the immediate precursor to invasive cervical cancer, is more difficult to measure because of its lower incidence, but provides the most stringent evidence of potential cancer prevention. We report vaccine efficacy against CIN3+ and adenocarcinoma in situ (AIS) in the end-of-study analysis of PATRICIA (PApilloma TRIal against Cancer In young Adults).

METHODS

Healthy women aged 15-25 years with no more than six lifetime sexual partners were included in PATRICIA, irrespective of their baseline HPV DNA status, HPV-16 or HPV-18 serostatus, or cytology. Women were randomly assigned (1:1) to receive an HPV-16/18 AS04-adjuvanted vaccine or a control hepatitis A vaccine via an internet-based central randomisation system using a minimisation algorithm to account for age ranges and study sites. The patients and study investigators were masked to allocated vaccine. The primary endpoint of PATRICIA has been reported previously. In the present end-of-study analysis, we focus on CIN3+ and AIS in the populations of most clinical interest, the total vaccinated cohort (TVC) and the TVC-naive. The TVC comprised all women who received at least one vaccine dose, approximating catch-up populations and including sexually active women (vaccine n=9319; control=9325). The TVC-naive comprised women with no evidence of oncogenic HPV infection at baseline, approximating early adolescent HPV exposure (vaccine n=5824; control=5820). This study is registered with ClinicalTrials.gov, number NCT00122681.

FINDINGS

Vaccine efficacy against CIN3+ associated with HPV-16/18 was 100% (95% CI 85·5-100) in the TVC-naive and 45·7% (22·9-62·2) in the TVC. Vaccine efficacy against all CIN3+ (irrespective of HPV type in the lesion and including lesions with no HPV DNA detected) was 93·2% (78·9-98·7) in the TVC-naive and 45·6% (28·8-58·7) in the TVC. In the TVC-naive, vaccine efficacy against all CIN3+ was higher than 90% in all age groups. In the TVC, vaccine efficacy against all CIN3+ and CIN3+ associated with HPV-16/18 was highest in the 15-17 year age group and progressively decreased in the 18-20 year and 21-25 year age groups. Vaccine efficacy against all AIS was 100% (31·0-100) and 76·9% (16·0-95·8) in the TVC-naive and TVC, respectively. Serious adverse events occurred in 835 (9·0%) and 829 (8·9%) women in the vaccine and control groups, respectively; only ten events (0·1%) and five events (0·1%), respectively, were considered to be related to vaccination.

INTERPRETATION

PATRICIA end-of-study results show excellent vaccine efficacy against CIN3+ and AIS irrespective of HPV DNA in the lesion. Population-based vaccination that incorporates the HPV-16/18 vaccine and high coverage of early adolescents might have the potential to substantially reduce the incidence of cervical cancer.

FUNDING

GlaxoSmithKline Biologicals.

Aspects of prophylactic vaccination against cervical cancer and other human papillomavirus-related cancers in developing countries

Cervical cancer and other human papillomavirus- (HPV-) related cancers are preventable, but preventive measures implemented in developing countries and especially in low-income rural regions have not been effective. Cervical cancer burden derived from sexually transmitted HPV infections is the heaviest in developing countries, and a dramatic increase in the number of cervical cancer cases is predicted, if no intervention is implemented in the near future. HPV vaccines offer an efficient way to prevent related cancers. Recently implemented school-based HPV vaccination demonstration programmes can help tackle the challenges linked with vaccine coverage, and access to vaccination and health services, but prevention strategies need to be modified according to regional characteristics. In urban regions WHO-recommended vaccination strategies might be enough to significantly reduce HPV-related disease burden, but in the rural regions additional vaccination strategies, vaccinating both sexes rather than only females when school attendance is the highest and applying a two-dose regime, need to be considered. From the point of view of both public health and ethics identification of the most effective prevention strategies is pivotal, especially when access to health services is limited. Considering cost-effectiveness versus justice further research on optional vaccination strategies is warranted.

What types of contacts are important for the spread of infections?: using contact survey data to explore European mixing patterns

Knowledge of the determinants of infectious disease transmission is a public health priority as it allows the design of optimal control strategies for endemic or emerging infections. We analyse a detailed dataset on contact patterns across five European countries and use available serological profiles for varicella and parvovirus B19 infections to identify the types of contact that may be most relevant for transmission. We show that models informed by contact data fit well the observed serological profiles of both infections. We find that intimate types of contacts explain the pattern of acquisition of serological markers by age better than other types of social contacts. We observe similar patterns in each of the countries analysed, suggesting that there are consistent biological mechanisms at work.

The ethics of implementing human papillomavirus vaccination in developed countries

Human papillomavirus (HPV) infection is the world's most common sexually transmitted infection. It is a prerequisite for cervical cancer, the second most common cause of death in cancer among women worldwide, and is also believed to cause other anogenital and head and neck cancers. Vaccines that protect against the most common cancer-causing HPV types have recently become available, and different countries have taken different approaches to implementing vaccination. This paper examines the ethics of alternative HPV vaccination strategies. It devotes particular attention to the major arguments for and against one strategy: voluntary, publicly funded vaccination for all adolescent boys and girls. This approach seems attractive because it would protect more people against cervical cancer and other HPV-related cancers than less inclusive alternatives, without the sacrifice of autonomy that a comparably broad compulsory programme would require. Also, the herd immunity that it would likely generate would protect those who remain unvaccinated, a major advantage from a justice perspective. However, there is a possibility that a HPV vaccination programme targeting all adolescents of both sexes is not considered sufficiently cost-effective. Also, it might pose more difficulties for achieving informed consent than comparable vaccination programmes against other diseases. Ultimately, society's choice of HPV vaccination strategy requires careful consideration not only of the values at stake but also of available and emerging scientific evidence.

Monitoring of human papillomavirus vaccination

Persistent infection with oncogenic human papillomavirus (HPV) is a necessary causal factor in the development of cervical cancer. Moreover, HPV, predominately type 16 and to a lesser degree type 18, is linked causally to varying proportions of other anogenital cancers (vulva, vagina, penis, anus) as well as cancers elsewhere in the body (oropharynx, larynx, conjunctiva). HPV types 6 and 11 cause most of genital warts and recurrent respiratory papillomatosis. Effective prophylactic vaccines have been developed. In this review, we address briefly the immunological aspects of HPV infection and the results of HPV vaccination trials. Internationally standardized monitoring and evaluation of prophylactic HPV vaccination programmes will be essential for arriving at the most cost-effective strategies for cancer control.

Cost-effectiveness of 12- and 15-year-old girls’ human papillomavirus 16/18 population-based vaccination programmes in Lithuania

Background: There is a large difference in the prevalence of cervical cancer between European countries. Between European Union countries, cervical cancer is the most prevalent in Lithuania. Currently we have available vaccines for different types of human papillomavirus virus (HPV), but we lack evidence on how the vaccination would be cost-effective in low-resource Eastern European countries like Lithuania. Objectives: To create a simulation model for the Lithuanian population; to estimate epidemiological benefits and cost-effectiveness for a HPV16/18 vaccination programme in Lithuania. Study design: For the cost-effectiveness analysis, we used Lithuanian population mathematical simulation and epidemiological data modelling. We performed comparative analysis of annual vaccination programmes of 12-year-old or 15-year-old girls at different vaccine penetration levels. Population: Lithuanian female population at all age groups. Results: A vaccination programme in Lithuania would gain an average of 35.6 life years per death avoided. Vaccinated girls would experience up to 76.9% overall reduction in incidence of cervical cancers, 80.8% reduction in morbidity and 77.9% reduction in mortality over their lifetime. Cost per life year gained with different vaccine penetration levels would range from 2167.41 to 2999.74. Conclusions: HPV vaccination in Lithuania would have a very positive impact on the epidemiological situation and it would be cost-effective at all ranges of vaccine penetration. Vaccination in Lithuania in the long term potentially could be more cost-effective due to avoiding early disease onset and lower accumulation of period costs.

Understanding differences in predictions of HPV vaccine effectiveness: A comparative model-based analysis

Mathematical models of HPV vaccine effectiveness and cost-effectiveness have produced conflicting results. The aim of this study was to use mathematical models to compare and isolate the impact of the assumptions most commonly made when modeling the effectiveness of HPV vaccines. Our results clearly show that differences in how we model natural immunity, herd immunity, partnership duration, HPV types, and waning of vaccine protection lead to important differences in the predicted effectiveness of HPV vaccines. These results are important and useful to assist modelers/health economists in choosing the appropriate level of complexity to include in their models, provide epidemiologists with insight on key data necessary to increase the robustness of model predictions, and help decision makers better understand the reasons underlying conflicting results from HPV models.

Prevention strategies against human papillomavirus in males

Sexually transmitted human papillomavirus (HPV) infection is very common in men and women. Oncogenic HPV is strongly associated with cancers and high-grade dysplasias of the anogenital tract, including the anus, penis, and also a proportion of oropharyngeal cancers. In reducing male disease burden, some consider screening and treatment for high-grade anal dysplasia (AIN) to prevent anal cancer in high-risk populations. Such strategies have wide implications for the workforce, and require more evidence for the optimal management of AIN. Male sexual behavior, with consequent HPV infection and disease contribute to considerable disease burden in females. Hence, inclusion of males in prophylactic HPV vaccination programs should prevent HPV-related disease in males as well as substantially reducing disease burden in females. Clinical trial data in males 16-26 years for the quadrivalent vaccine show it is well tolerated, induces a strong type-specific immunological response comparable to that of females, and reduced vaccine HPV-type-related genital infection, as well as disease. Cost-benefit analyses and mathematical modeling show that the most cost-effective strategy involves routine administration of this vaccine to 12-year-old females, with catch-up vaccination of 12- to 24-year-olds, with the most effective strategy in disease reduction including men and/or boys in the program. Such a vaccination strategy including 12-year-old boys is projected by 2050 to reduce HPV 16 infection by 88-94% in females and 68-82% in males, plus the aforementioned male HPV- related cancers by 22-27%. Therefore, inclusion of males in an HPV vaccination program is likely to have significant health and economic benefits over and above those observed from current female-only programs. However, comprehensive cost-benefit analyses are needed to determine the efficacy of these programs in the overall population. Such analyses will be crucial for the design, acceptance, and implementation of these vaccination programs into clinical practice globally.

Human papilloma viruses and cancer in the post-vaccine era

Human papilloma viruses (HPV) are strong human carcinogens, in fact today they are considered as the second most frequent carcinogen. In the middle of the 1970s the hypothesis that cervical cancer may arise from viruses was established and in the 1990s the relationship between HPV and cervical neoplasia was confirmed. HPV infections are the most common sexually transmitted infections. Specific subtypes of human papilomaviruses are now considered as the etiological agents in nearly all cases of cervical cancer and cervical epithelial neoplasia. Approximately 470,000 new cases and 23,000 deaths of cervical cancer occur each year, with the majority taking place in developing countries. Cervical cancer remains among the three leading causes of cancer deaths among women below the age of 45. Human papilomaviruses are classified into two groups: high-risk (oncogenic) types and low risk types. HPV types 16, 18, 45 and 31 are considered to be the most important oncogenic types. Subtypes 16 and 18 are the causative agents of more than 50% of cervical pre-cancerous lesions, and more than 70% of cervical cancer cases. High risk subtypes are also implicated with anal, perianal and oropharyngeal carcinomas. Recently, the prophylactic bivalent HPV 16/18 and the quadrivalent HPV 6/11/16/18/ vaccines have been approved. The development of prophylactic vaccines against human papilomavirus has been hailed as one of the most significant advances of recent years and it is expected to reduce dramatically the mortality of human papilomavirus associated cancers, but has also given rise to some of the most intense scientific debates.

Transmission dynamic modelling of the impact of human papillomavirus vaccination in the United Kingdom

Many countries are considering vaccination against human papillomavirus (HPV). However, the long-term impact of vaccination is difficult to predict due to uncertainty about the prevalence of HPV infection, pattern of sexual partnerships, progression of cervical neoplasias, accuracy of screening as well as the duration of infectiousness and immunity. Dynamic models of human papillomavirus (HPV) transmission were developed to describe the infection spread and development of cervical neoplasia, cervical cancer (squamous cell and adenocarcinoma) and anogenital warts. Using different combinations of assumptions, 9900 scenarios were created. Each scenario was then fitted to epidemiological data and the best-fitting scenarios used to predict the impact of vaccination. Results suggest that vaccinating 12-year-old girls at 80% coverage will result in a 38-82% reduction in cervical cancer incidence and 44-100% reduction in anogenital warts incidence after 60 years of an ongoing vaccination programme if vaccine protection lasts 20 years on average. The marginal benefit of vaccinating boys depends on the degree of protection achieved by vaccinating girls.

Mathematical modeling and the epidemiological research process

The authors of this paper advocate for the expanded use of mathematical models in epidemiology and provide an overview of the principles of mathematical modeling. Mathematical models can be used throughout the epidemiological research process. Initially they may help to refine study questions by visually expressing complex systems, directing literature searches, and identifying sensitive variables. In the study design phase, models can be used to test sampling strategies, to estimate sample size and power, and to predict outcomes for studies impractical due to time or ethical considerations. Once data are collected, models can assist in the interpretation of results, the exploration of causal pathways, and the combined analysis of data from multiple sources. Finally, models are commonly used in the process of applying research findings to public health practice by estimating population risk, predicting the effects of interventions, and contributing to the evaluation of ongoing programs. Mathematical modeling has the potential to make significant contributions to the field of epidemiology by enhancing the research process, serving as a tool for communicating findings to policymakers, and fostering interdisciplinary collaboration.

Cost-effectiveness of human papillomavirus vaccination and cervical cancer screening in women older than 30 years in the United States

BACKGROUND

Women older than 30 years are the main beneficiaries of improved cervical cancer screening with human papillomavirus (HPV) DNA testing. The role of vaccination against HPV types 16 and 18, which is recommended routinely for preadolescent girls, is unclear in this age group.

OBJECTIVE

To assess the health and economic outcomes of HPV vaccination in older U.S. women.

DESIGN

Cost-effectiveness analysis with an empirically calibrated model.

DATA SOURCES

Published literature.

TARGET POPULATION

U.S. women aged 35 to 45 years.

TIME HORIZON

Lifetime.

PERSPECTIVE

Societal.

INTERVENTION

HPV vaccination added to screening strategies that differ by test (cytology or HPV DNA testing), frequency, and start age versus screening alone.

OUTCOME MEASURES

Incremental cost-effectiveness ratios (2006 U.S. dollars per quality-adjusted life-year [QALY] gained).

RESULTS OF BASE-CASE ANALYSIS

In the context of annual or biennial screening, HPV vaccination of women aged 35 to 45 years ranged from $116 950 to $272 350 per QALY for cytology with HPV DNA testing for triage of equivocal results and from $193 690 to $381 590 per QALY for combined cytology and HPV DNA testing, depending on age and screening frequency.

RESULTS OF SENSITIVITY ANALYSIS

The probability of HPV vaccination being cost-effective for women aged 35 to 45 years was 0% with annual or biennial screening and less than 5% with triennial screening, at thresholds considered good value for money.

LIMITATION

The natural history of the disease and the efficacy of the vaccine in older women are uncertain.

CONCLUSION

Given currently available information, the effectiveness of HPV vaccination for women older than 30 years who are screened seems to be small. Compared with current screening that uses sensitive HPV DNA testing, HPV vaccination is associated with less attractive cost-effectiveness ratios in this population than those for other, well-accepted interventions in the United States.

Sexual behaviour in Ligurian (Northern Italy) adolescents and young people: suggestions for HPV vaccination policies

Human papillomavirus is a common sexually transmitted virus, and persistent infection with high-risk types is the necessary factor for cervical cancer. We investigated sexual behaviour and the age of the first sexual intercourse among young people (14-24 years) in Liguria (Northern Italy) in order to provide information that might orient the country's future vaccination policy. The Italian Authorities offer free vaccination to 12-year-old females, however a better prevention of HPV would to be implemented by introducing the vaccine to new cohorts of females after the first year of the vaccination campaign. Our survey was carried out from 1st May 2006 to 31st December 2007 and involved 3474 volunteers. We administered a written questionnaire to students (14-24 years) and workers (20-24 years). The median age+/-MAD of the sexual debut was 15+/-1 for both females and males in students group and 16+/-1 for both males and females in workers group. This study provides evidence that many Ligurian adolescents have their first sexual experience at a very early age, and often without protection against sexually transmitted diseases. Furthermore, a large percentage of all age-groups are sexually active and have multiple partners. The aim of this study was to identify those cohorts of females to whom vaccination should be offered free of charge. To this end, we calculated the percentage of infections that could be avoided by vaccination in each age-class: the younger the subjects, the higher the number of preventable infections. Our findings suggest that current HPV vaccination should be implemented by introducing new cohorts, especially young girls (14-16 years).

[HPV immunization for the prevention of cervical cancer]

CONTEXT

Human Papillomaviruses (HPV) infect epithelial cells of the skin and mucosae. Mucosal high-risk HPV types (mainly HPV 16 and 18) are involved in the development of cervical cancer, one of the most common cancers in young women. HPV infection is usually asymptomatic and clears spontaneously, but 10 - 15 % of high-risk HPV infections are persistent and increase the risk of precancerous and cancerous lesions of the cervix. Two HPV vaccines have been licensed to provide protection against cervical cancer.

OBJECTIVES

To report the different aspects of HPV infection in order to improve the understanding of the particular problems of HPV vaccination and to review the most recent findings related to HPV vaccines, particularly regarding the protective efficacy of vaccines and the roles of adjuvants and immune response in protection.

METHODS

Articles were selected from the PubMed database (National Library of Medicine- National Institute of Health) with the following Keywords "HPV", "Prevention", "HPV vaccines", "Immune response", "Antibody". Abstracts of oral presentations from international meetings were also selected for the more recent findings. a critical analysis of the majority of papers published was undertaken and relevant information summarized.

RESULTS

Virus-like particle production by expressing the major protein of the HPV capsid was carried out in the early 90's, leading to the recent development of two HPV vaccines. These vaccines are now licensed in many countries and have been demonstrated to be highly immunogenic. In subjects that are non-infected at the time of vaccination, HPV vaccines are highly effective in preventing persistent HPV 16 - 18 infections (90 %) and precursors lesions of cervical cancer associated with these two HPV types (close to 100 %). Clinical trials have also confirmed that HPV vaccines are well tolerated by recipients.

CONCLUSIONS

The present paper is a detailed review published in French on HPV vaccines, their efficacy in the prevention of HPV infections and unresolved questions regarding the use of HPV vaccines. This report also includes biological and immunological information to improve the understanding of HPV vaccination.

Immunogenicity and safety of human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine in healthy boys aged 10-18 years

PURPOSE

The human papillomavirus (HPV)-16/18 AS04-adjuvanted vaccine (Cervarix) has been shown to be well-tolerated and immunogenic in females aged 10 to 55 years, and up to 100% effective for the prevention of HPV-16/18 infection and associated precancerous cervical lesions in females aged 15 to 25 years. This study is the first to evaluate the immunogenicity and safety of the vaccine in males.

METHODS

Healthy males aged 10 to 18 years were randomized (2:1 ratio) to receive HPV-16/18 AS04-adjuvanted vaccine (n = 181) or hepatitis B virus (HBV) control vaccine (n = 89) at 0, 1, and 6 months, and were followed for 7 months.

RESULTS

All initially seronegative subjects in the HPV-16/18 group seroconverted for HPV-16 and 18 (ELISA) at month 2. At month 7, all subjects were seropositive, and the HPV-16 and -18 antibody levels were, respectively, four- and twofold higher than at month 2. The anti-HPV-16 and -18 antibody responses for males aged 10 to 18 years and 10 to 14 years, respectively, were higher than those reported for females aged 15 to 25 years and 10 to 14 years, respectively, in a previous study. The reactogenicity profiles of the HPV-16/18 AS04 and HBV vaccines were similar, except that pain and swelling at the injection site were more common in the HPV-16/18 group. However, vaccine-related symptoms did not affect compliance with the three-dose course, which was equally high (97%) in both groups.

CONCLUSIONS

The HPV-16/18 AS04-adjuvanted vaccine is immunogenic and well tolerated in boys aged 10 to 18 years. However, further data on the potential public health benefits of vaccination of boys are required before any recommendations can be made.

Effectiveness and cost effectiveness of human papillomavirus vaccine: a systematic review

The recent approval of human papillomavirus (HPV) vaccine means that decision makers need information beyond that available from randomized clinical trials to recommend funding for this vaccination programme. Modelling and economic studies have addressed some of those information needs. We conducted a qualitative systematic review to summarize the existing data. Review articles were obtained from an extensive literature search on studies using mathematical modelling (either a Markov or transmission dynamic model) to determine the effectiveness or cost effectiveness of an HPV vaccine compared with the current cytology-based Pap smear screening programme. A total of 21 studies (but 22 models) were included in the review after being assessed for methodological quality. All of the included studies had used a mathematical model to determine the effectiveness of an HPV vaccine, whilst 13 had also conducted a cost-effectiveness analysis. Although the studies used different model structures, baseline parameters and assumptions, all studies showed that vaccination would decrease rates of HPV infection, precancerous lesions and cervical cancer. Studies had a consistent message with respect to cost effectiveness: a female-only vaccination programme is cost effective compared with the current cytology-based Pap smear screening programme, while the cost effectiveness of a male and female vaccination programme is generally not cost effective compared with female-only vaccination.

An update of prophylactic human papillomavirus L1 virus-like particle vaccine clinical trial results

This review focuses on recent publications of clinical trials of two prophylactic human papillomavirus (HPV) vaccines: Gardasil (Merck & Co., Inc., Whitehouse Station, NJ USA), a quadrivalent vaccine containing L1 virus-like particles (VLPs) of types -6, 11, 16, and 18, and Cervarix (GlaxoSmithKline Biologicals, Rixensart, Belgium), a bivalent vaccine containing VLPs of types -16 and 18. In efficacy trials involving young women, both vaccines produced outstanding efficacy against primary and secondary endpoints associated with the vaccine type HPVs and were highly and consistently immunogenic. Both had excellent safety records and, as expected, the most frequent vaccine-related adverse were mild to moderate injection site sequelae. No evidence of waning protection was observed after four years for endpoints examined ranging from incident infection to cervical intraepithelial neoplasia grade 3 associated with the vaccine type HPVs. Gardasil was also highly efficacious at preventing vaginal/vulvar lesions and genital warts. However, neither vaccine demonstrated therapeutic efficacy against prevalent infections or lesions, regardless of the associated HPV type. Cervarix has shown limited cross-protection against infection with specific closely related types while preliminary results of limited cross-protection have been presented for Gardasil. As expected, more limited efficacy was noted for both vaccines when women with prevalent infection were included or endpoints associated with any HPV type were evaluated. Immunological bridging trials involving adolescent girls and boys were also recently published. For both vaccines, serum VLP antibody levels in girls were non-inferior to those generated in young women and antibody response to Gardasil was also non-inferior in boys. The results of these studies have led to the approval of Gardasil and Cervarix by national regulatory agencies in a number of countries.

Modeling cervical cancer prevention in developed countries

Cytology-based screening has reduced cervical cancer mortality in countries able to implement, sustain and financially support organized programs that achieve broad coverage. These ongoing secondary prevention efforts considerably complicate the question of whether vaccination against human papillomavirus (HPV) types 16 and 18 should be introduced. Policy questions focus primarily on the target ages of vaccination, appropriate ages for a temporary "catch-up" program, possible revisions in screening policies to optimize synergies with vaccination, including the increased used of HPV DNA testing, and the inclusion of boys in the vaccination program. Decision-analytic models are increasingly being developed to simulate disease burden and interventions in different settings in order to evaluate the benefits and cost-effectiveness of primary and secondary interventions for informed decision-making. This article is a focused review on existing mathematical models that have been used to evaluate HPV vaccination in the context of developed countries with existing screening programs. Despite variations in model assumptions and uncertainty in existing data, pre-adolescent vaccination of girls has been consistently found to be attractive in the context of current screening practices, provided there is complete and lifelong vaccine protection and widespread vaccination coverage. Questions related to catch-up vaccination programs, potential benefits of other non-cervical cancer outcomes and inclusion of boys are subject to far more uncertainty, and results from these analyses have reached conflicting conclusions. Most analyses find that some catch-up vaccination is warranted but becomes increasingly unattractive as the catch-up age is extended, and vaccination of boys is unlikely to be cost-effective if reasonable levels of coverage are achieved in girls or coverage among girls can be improved. The objective of this review is to highlight points of consensus and qualitative themes, to discuss the areas of divergent findings, and to provide insight into critical decisions related to cervical cancer prevention.

Reductions in human papillomavirus-disease resource use and costs with quadrivalent human papillomavirus (types 6, 11, 16, and 18) recombinant vaccination: the FUTURE Study Economic Evaluation

OBJECTIVE

To examine the short-term impact of quadrivalent human papillomavirus (HPV) (types 6/11/16/18) recombinant vaccination upon HPV disease-related health-care resource utilization and costs among young women.

METHODS

We analyzed data from a randomized clinical trial comparing quadrivalent vaccination to placebo, among women (N = 7861) primarily 16 to 23 years of age at enrollment. HPV disease episodes, health-care resource utilization and costs associated with cervical, vaginal, and vulvar precancers, and anogenital warts were analyzed over a period of 2.5 years among women, regardless of baseline HPV status.

RESULTS

Overall, there was a 25.9% (P < 0.001) reduction in total HPV disease-related health-care costs among women receiving vaccine versus placebo (absolute reduction $3939 per 100 trial enrollees). We observed similar overall reductions in HPV-disease episodes and resource utilization. There was a statistically significant reduction in HPV 6/11-related disease episode costs of 65.1% ($1837 per 100), and a reduction of 51.4% ($1781 per 100) in HPV 16/18-related episode costs.

CONCLUSIONS

Quadrivalent HPV vaccination can reduce HPV disease events, resource use and costs when administered to a broad population of young women 16 to 23 years of age. Prevention of HPV types 6 and 11 yielded similar value in terms of HPV disease cost offsets, compared to protection against HPV 16 and 18, during the years initially after vaccination. Over the short-term, costs of vaccination exceed cost offsets associated with prevention of HPV disease; however, quadrivalent HPV vaccination has previously been shown to be cost-effective in the longer term, when fully accounting for health benefits and cost offsets.

Human papillomavirus infection and the primary and secondary prevention of cervical cancer

A wealth of evidence has led to the conclusion that virtually all cases of cervical cancer are attributable to persistent infection by a subset of human papillomavirus (HPV) types, especially HPV type 16 (HPV-16) and HPV-18. These HPV types also cause a proportion of other cancers, including vulvar, vaginal, anal, penile, and oropharyngeal cancers. Although cervical cancer screening, primarily with the Papanicolaou (Pap) smear, has reduced the incidence of this cancer in industrialized countries, cervical cancer remains the second most common cause of death from cancer in women worldwide, because the developing world has lacked the resources for widespread, high-quality screening. In addition to advances in Pap smear technology, the identification of HPV as the etiologic agent has produced 2 recent advances that may have a major impact on approaches to reduce the incidence of this disease. The first is the development of a preventive vaccine, the current versions of which appear to prevent close to 100% of persistent genital infection and disease caused by HPV-16 and HPV-18; future second-generation vaccines may be able to protect against oncogenic infections by a broader array of HPV types. The second is the incorporation of HPV testing into screening programs. In women aged >30 years, HPV testing can identify high-grade cervical intraepithelial neoplasia earlier than Pap smears with acceptable rates of specificity. These results, together with the high sensitivity of HPV testing, suggest that such testing could permit increased intervals for screening. An inexpensive HPV test in development, if successful, may be incorporated as part of an economically viable 'screen-and-treat' approach in the developing world. The manner in which vaccination and screening programs are integrated will need to be considered carefully so that they are efficient in reducing the overall incidence of cervical cancer.