Low prevalence of vaccine-type HPV infections in young women following the implementation of a school-based and catch-up vaccination in Quebec, Canada

Real-world impact and effectiveness of the quadrivalent HPV vaccine: an updated systematic literature review

INTRODUCTION

Human papillomavirus (HPV) infection, which poses significant disease burden, is decreasing following implementation of vaccination programs. Synthesized evidence on HPV vaccine real-world benefit was published in 2016. However, long-term impact of vaccination, and how vaccination programs influence infection rates and disease outcomes, requires further examination.

AREAS COVERED

We systematically reviewed observational studies on HPV vaccination within MEDLINE, EMBASE, and Google Scholar from 2016 to 2020, involving 14 years of follow-up data. We identified 138 peer-reviewed publications reporting HPV vaccine impact or effectiveness. Outcomes of interest included rates of infection at different anatomical sites and incidence of several HPV-related disease endpoints.

EXPERT OPINION

The expansion of HPV vaccination programs worldwide has led to a reduction in genital infection and significant decreases in incidence of HPV-related disease outcomes. Therefore, the WHO has set goals for the elimination of cervical cancer as a public health concern. To track progress toward this requires an understanding of the effectiveness of different vaccination initiatives. However, the impact on males, and potential benefit of gender-neutral vaccination programs have not been fully explored. To present an accurate commentary on the current outlook of vaccination and to help shape policy therefore requires a systematic review of available data.

Prevalence, Diversity, and Risk Factors for Cervical HPV Infection in Women Screened for Cervical Cancer in Belém, Pará, Northern Brazil

Background: Human papillomavirus (HPV) is the most common viral sexually transmitted infection of the reproductive tract, and cervical cancer is the most common HPV-related disease. This study estimated the prevalence, diversity of HPV genotypes, and associated risk factors in women screened for cervical cancer in northern Brazil. Methods: The cross-sectional study was conducted in Belém, Pará, in the Amazon region of Brazil, and it included 162 women who were spontaneously undergoing a Pap-smear routine. Epidemiological, sexual, and health-related information was collected by interviews, and cervical samples were collected for cytological examination and HPV-DNA detection. HPV genotypes were classified as low risk (LR) and high risk (HR) by nucleotide sequencing. Results: In total, 17.3% (28/162) of the participants had HPV-DNA, and LR-HPV was the most prevalent (71.4%). Among the 13 different types of HPV detected, HPV-11 was found most frequently (12/28; 42.9%), followed by HPV-31 (3/28; 10.7%). Of the participants with cytological alterations, HPV infection was detected in only four: two were diagnosed with low-grade squamous intraepithelial lesions (15.4%), one with atypical squamous cells of undetermined significance (7.7%), and one with atypical squamous cells, cannot exclude high-grade squamous intraepithelial lesions (7.7%). Of the 61 women who presented a normal cytology, 13 (21.3%) had positive tests for HPV infection, 4 (8.2%) of which were positive for a high-risk genotype. Conclusion: The prevalence of HPV was high in Belém, Pará, and especially in women who had normal cytology results, which suggests the need for greater screening for HPV infection in women’s primary health care.

Real-world impact and effectiveness assessment of the quadrivalent HPV vaccine: a systematic review of study designs and data sources

INTRODUCTION

Vaccine effectiveness and impact studies are typically observational, generating evidence after vaccine launch in a real-world setting. For human papillomavirus (HPV) vaccination studies, the variety of data sources and methods used is pronounced. Careful selection of study design, data capture and analytical methods can mitigate potential bias in such studies.

AREAS COVERED

We systematically reviewed the different study designs, methods, and data sources in published evidence (1/2007-3/2020), which assessed the quadrivalent HPV vaccine effectiveness and impact on cervical/cervicovaginal, anal, and oral HPV infections, anogenital warts, lesions in anus, cervix, oropharynx, penis, vagina or vulva, and recurrent respiratory papillomatosis.

EXPERT OPINION

The rapid growth in access to real-world data allows global monitoring of effects of different public health interventions, including HPV vaccination programs. But the use of data which are not collected or organized to support research also underscore a need to develop robust methodology that provides insight of vaccine effects and consequences of different health policy decisions. To achieve the WHO elimination goal, we foresee a growing need to evaluate HPV vaccination programs globally. A critical appraisal summary of methodology used will provide timely guidance to researchers who want to initiate research activities in various settings.

Sexual behavior, clinical outcomes and attendance of cervical cancer screening by HPV vaccinated and unvaccinated sexually active women

Concerns were raised about HPV vaccination possibly leading to riskier sexual behavior. We assessed sexual behaviors, risk of sexually transmitted infection, and attendance to cervical cancer screening by HPV vaccinated and unvaccinated young women. In this analysis, 1475 questionnaires completed by women aged 17-29 years were included. The majority of respondents (67.9%) were vaccinated against HPV. The proportion of those vaccinated decreased with age: from 93.2% in those aged 17-19 to 72.9% in those aged 20-22, and 21.8% in 23-29-year olds. A higher proportion of unvaccinated respondents had at least one sexual intercourse under the age of 15 when compared to those vaccinated (30% vs. 23%, p < .0001). The number of sexual partners during the last 12 months was similar between vaccinated and unvaccinated participants. Vaccinated participants reported more condom use (45% versus 38%; p = .0002), and less sexually transmitted infections (10% versus 28%; p < .0001), and less anogenital condylomas (2.2% vs. 11.6%; p < .0001). A screening test has been reported by 51% and 77% of vaccinated and unvaccinated participants, respectively (p < .0001). The association between vaccination status and cervical cancer screening disappeared when adjusting for participants' age. The study results consolidate the existing body of data regarding the absence of an impact of HPV vaccination on sexual behavior or use of contraceptives.

Brazilian Protocol for Sexually Transmitted Infections 2020: human papillomavirus (HPV) infection

This article addresses human papillomavirus (HPV) infection, one of the topics covered by the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections, published by the Brazilian Ministry of Health. The Protocol and Guidelines have been developed based on scientific evidence and validated in discussions with specialists. This article presents epidemiological and clinical aspects and guidelines for health service managers and health workers about diagnosing and treating people with papillomavirus infection. This theme is a significant public health issue since it is the most prevalent sexually transmitted infection globally, capable of triggering the oncogenic process of cervical cancer and the possibility of anogenital warts. Important information is presented for gaining knowledge about HPV and action strategies for infection prevention and control, provision of quality care, and effective treatment of the disease. Infection by the human papillomavirus is the sexually transmitted infection of the highest contagion, superior to genital herpes and HIV.

[Brazilian Protocol for Sexually Transmitted Infections 2020: human papillomavirus (HPV) infection]

This article addresses human papillomavirus (HPV) infection, this being one of the topics covered by the Clinical Protocol and Therapeutic Guidelines for Comprehensive Care for People with Sexually Transmitted Infections, published by the Brazilian Ministry of Health. The Protocol and Guidelines have been developed based on scientific evidence and validated in discussions with specialists. This article presents epidemiological and clinical aspects, as well as guidelines for health service managers and health workers about diagnosing and treating people with papillomavirus infection. This theme is an important public health problem, since it is the most prevalent sexually transmitted infection in the world, capable of triggering the oncogenic process of cervical cancer, as well as the possibility anogenital warts occurring. Important information is presented for gaining knowledge about HPV, as well as action strategies for infection prevention and control, provision of quality care and effective treatment of the disease.

Systematic literature review of cross-protective effect of HPV vaccines based on data from randomized clinical trials and real-world evidence

BACKGROUND

The extent of cross-protection provided by currently licensed bivalent and quadrivalent HPV vaccines versus direct protection against HPV 31-, 33-, 45-, 52-, and 58-related disease is debated. A systematic literature review was conducted to establish the duration and magnitude of cross-protection in interventional and observational studies.

METHODS

PubMed and Embase databases were searched to identify randomized controlled trials (RCT) and observational studies published between 2008 and 2019 reporting on efficacy and effectiveness of HPV vaccines in women against non-vaccine types 31, 33, 45, 52, 58, and 6 and 11 (non-bivalent types). Key outcomes of interest were vaccine efficacy against 6- and 12-month persistent infection or genital lesions, and type-specific genital HPV prevalence or incidence. RCT data were analyzed for the according-to-protocol (bivalent vaccine) or negative-for-14-HPV-types (quadrivalent vaccine) efficacy cohorts.

RESULTS

Data from 23 RCTs and 33 observational studies evaluating cross-protection were extracted. RCTs assessed cross-protection in post-hoc analyses of small size subgroups. Among fully vaccinated, baseline HPV-naïve women, the bivalent vaccine showed statistically significant cross-protective efficacy, although with wide confidence intervals, against 6-month and 12-month persistent cervical infections and CIN2+ only consistently for HPV 31 and 45, with the highest effect observed for HPV 31 (range 64.6% [95% CI: 27.6 to 83.9] to 79.1% [97.7% CI: 27.6 to 95.9] for 6-month persistent infection; maximal follow-up 4.7 years). No cross-protection was shown in extended follow-up. The quadrivalent vaccine efficacy reached statistical significance for HPV 31 (46.2% [15.3-66.4]; follow-up: 3.6 years). Similarly, observational studies found consistently significant effectiveness only against HPV 31 and 45 with both vaccines.

CONCLUSIONS

RCTs and observational studies show that cross-protection is inconsistent across non-vaccine HPV types and is largely driven by HPV 31 and 45. Furthermore, existing data suggest that it wanes over time; its long-term durability has not been established.

Improving adolescent human papillomavirus (HPV) immunization uptake in school-based health centers through awareness campaigns

PURPOSE

The aim of this study was to measure the effect of a multicomponent human papillomavirus (HPV) vaccine promotion campaign on adolescent HPV vaccine uptake at school-based health centers (SBHCs) in Seattle, WA.

METHODS

Youth-led HPV vaccine promotion campaigns were introduced in 2016 in 13 schools with SBHCs in Seattle. Five other schools with SBHCs served as controls. Vaccination records for students were obtained from the Washington Immunization Information System from September 2012 to August 2018. We compared increase in HPV vaccine uptake in SBHCs between 1) intervention and control schools, and 2) pre- and post-intervention periods in intervention schools using generalized estimating equations.

RESULTS

HPV vaccine uptake was high at baseline among students that use SBHCs for vaccines and has steadily increased between 2012 and 2018. Implementing the promotion campaign resulted in 14% higher (95% Confidence Interval (CI): 1%, 30%) HPV vaccine uptake in intervention SBHCs compared to control SBHCs, adjusting for time and confounders. Comparing pre-and post-intervention periods in intervention SBHCs, HPV vaccine uptake was 14% higher (95% CI: -4%, 35%) in the post-intervention period. SBHCs that received more active intervention activities saw 9% higher (95% CI: 1%, 21%) vaccine uptake compared to those that received passive intervention.

CONCLUSION

The vaccination promotion program implemented in a school-based setting resulted in higher HPV vaccine uptake in the post-intervention period compared to pre-intervention period, but this increase was not statistically significant. Even so, schools that received more intervention activities for longer periods of time had higher HPV vaccine uptake.

FACTORS ASSOCIATED WITH ADOLESCENT COMPLIANCE WITH HUMAN PAPILLOMAVIRUS VACCINE: A CROSS-SECTIONAL STUDY

ABSTRACT Objective: to identify the factors associated with adolescent compliance with the human papillomavirus vaccine. Method: this is a cross-sectional study, developed through a school survey, in Teresina, Piauí, Brazil, whose data collection occurred in 2018. A scale was used to assess decision-making, attitudes, feelings and knowledge about the human papillomavirus, in addition to a questionnaire to collect sociodemographic, economic and vaccination status data. The variables were submitted to the multivariate model of logistic regression to explain factors associated with vaccination adeforemen. Results: the study sample consisted of 624 adolescents, 15 years old, attending the first year of high school, of which 22.8% received the human papillomavirus vaccine. Being male decreases the chance of complying with the vaccine by 50% (aOR=0.05). Moreover, disagreeing or disagreeing with or disagreeing with parents to make the decision to vaccinate their children also reduced the chances of vaccination by 66% (aOR=0.34), respectively, as well as disagreeing with or disagreeing that men do not take human papillomavirus, minimized the chances of vaccination complying with vaccination by 66% (aOR=0.34), when compared to those who disagreed with this statement. Conclusion: low adolescent compliance with human papillomavirus vaccine was identified. Adolescents remain susceptible to diseases related to the human papillomavirus. Therefore, vaccination strategies need to be rethought, with the offer of vaccination in schools, mediated by educational campaigns.

Prevalence of Vaccine Type Infections in Vaccinated and Non-Vaccinated Young Women: HPV-IMPACT, a Self-Sampling Study

Background: The human papillomavirus (HPV) vaccination program for young girls aged 11⁻26 years was introduced in Switzerland in 2008. The objective of this study was to evaluate the prevalence of high- and low-risk HPV in a population of undergraduate students using self-sampling for monitoring the HPV vaccination program's effect.

METHODS

Undergraduate women aged between 18⁻31 years, attending the Medical School and University of Applied Sciences in Geneva, were invited to participate in the study. Included women were asked to perform vaginal self-sampling for HPV testing using a dry cotton swab.

RESULTS

A total of 409 students participated in the study-aged 18⁻31 years-of which 69% of the participants were vaccinated with Gardasil HPV vaccine and 31% did not received the vaccine. About HPV prevalence, 7.2% of unvaccinated women were HPV 16 or 18 positive, while 1.1% of vaccinated women were infected by HPV 16 or 18 (p < 0.01). Prevalence of HPV 6 and 11 was 8.3% in non-vaccinated women versus 2.1% in vaccinated women (p < 0.02). We observed no cross-protection for the other HPV genotypes of a low- and high-risk strain.

CONCLUSIONS

Prevalence of HPV 6/11/16/18 was lower in vaccinated women versus unvaccinated women. Continued assessment of HPV vaccine effectiveness in real population is needed.

Prevalence and distribution of HPV genotypes and cervical-associated lesions in sexually active young French women following HPV vaccine

BACKGROUND

Despite the availability of safe and effective HPV vaccines in France, more than 80% of girls remain unvaccinated.

SETTING

A regional university hospital referral center in France.

OBJECTIVE

To estimate the overall prevalence and distribution of HPV in vaccinated, sexually active young French women who were screened for cervical cancer by cytology and HPV testing.

METHODS

High-risk HPV (HR-HPV) prevalence, genotype-specific prevalence and extent of multiple infections were assessed in 125 cervical samples from females with available vaccine data using hc2 assay and INNO-LiPA assay. HPV status was analyzed in accordance with cytological data.

RESULTS

In our series, mean age was 23 years, overall prevalence of HR-HPV was 52% and was correlated with the lesion grade. The diversity of HPV genotypes was broad. Single HR-HPV infections were identified in 11%, 21% and 47% of women with NILM, ASC-US/-H and LSIL respectively. Multiple infections with HR-HPV were detected in 28% of the specimens. Only 24.5% of women with NILM presented infections with 2 genotypes or more, vs 28% of women with ASC-US/-H and 35% of women with LSIL. The overall prevalence of genotypes covered by the quadrivalent vaccine was low (5.9%); with 4.2%, 0%, 0.8% and 0.8% for HPV 16, HPV 18, HPV 6 and HPV 11 respectively.

CONCLUSION

Among HPV-vaccinated young women, HR-HPV are detected at a high rate, and an association with the grade of cytological abnormalities was observed. However, HPV 16 and 18, both targeted by the vaccines, are remarkably rare among young French women since program implementation.