Risk factors for human papillomavirus infection and disease: A targeted literature summary.

Adolescents are the primary cohort for routine human papillomavirus (HPV) vaccination, but unvaccinated adults may also benefit. A lack of consensus on which adults to target and the presence of reimbursement barriers likely contribute to the lag in adult vaccinations, highlighting missed prevention opportunities. Understanding factors contributing to risk of HPV infection and disease could help in decision making on vaccination. This review summarizes existing literature on risk factors for HPV infection and disease and includes 153 studies reporting relative risks or odds ratios for factors associated with HPV infection or disease in adults, published between 2009 and 2020. Despite inconsistent design and reporting of risk factors across studies, this review confirmed several risk factors associated with adult infection, including human immunodeficiency virus positivity, number of sex partners, and smoking. These findings can support policymaking, guideline development, and clinical decision making for HPV vaccination and screening of high-risk adult groups.

Impact and Effectiveness of the Quadrivalent Human Papillomavirus Vaccine: A Systematic Review of 10 Years of Real-world Experience.

Prophylactic human papillomavirus (HPV) vaccination programs constitute major public health initiatives worldwide. We assessed the global effect of quadrivalent HPV (4vHPV) vaccination on HPV infection and disease. PubMed and Embase were systematically searched for peer-reviewed articles from January 2007 through February 2016 to identify observational studies reporting the impact or effectiveness of 4vHPV vaccination on infection, anogenital warts, and cervical cancer or precancerous lesions. Over the last decade, the impact of HPV vaccination in real-world settings has become increasingly evident, especially among girls vaccinated before HPV exposure in countries with high vaccine uptake. Maximal reductions of approximately 90% for HPV 6/11/16/18 infection, approximately 90% for genital warts, approximately 45% for low-grade cytological cervical abnormalities, and approximately 85% for high-grade histologically proven cervical abnormalities have been reported. The full public health potential of HPV vaccination is not yet realized. HPV-related disease remains a significant source of morbidity and mortality in developing and developed nations, underscoring the need for HPV vaccination programs with high population coverage.

Prophylactic HPV vaccines in patients with HPV-associated diseases and cancer.

Individuals with human papillomavirus (HPV)-related disease remain at risk for subsequent HPV infection and related disease after treatment of specific lesions. Prophylactic HPV vaccines have shown benefits in preventing subsequent HPV-related disease when administered before or soon after treatment. Based on our understanding of the HPV life cycle and vaccine mechanism of action, prophylactic HPV vaccination is not expected to clear active persistent HPV infection or unresected HPV-associated dysplastic tissue remaining after surgery. However, vaccination may reasonably be expected to prevent new HPV infections caused by a different HPV type as well as re-infection with the same HPV type, whether from a new exposure to an infected partner or through autoinoculation from an adjacent or distant productively infected site. In this review, we describe the evidence for using prophylactic HPV vaccines in patients with HPV-associated disease before, during, or after treatment and discuss potential mechanisms by which individuals with HPV-associated disease may or may not benefit from prophylactic vaccines. We also consider how precise terminology relating to the use of prophylactic vaccines in this population is critical to avoid the incorrect implication that prophylactic vaccines have direct therapeutic potential, which would be counter to the vaccine's mechanism of action, as well as considered off-label. In other words, the observed effects occur through the known mechanism of action of prophylactic HPV vaccines, namely by preventing virus of the same or a different HPV type from infecting the patient after the procedure.

Lessons Learned from the Development and Roll-Out of the rVSVΔG-ZEBOV-GP Zaire ebolavirus Vaccine to Inform Marburg Virus and Sudan ebolavirus Vaccines.

This review describes key aspects of the development of the rVSVΔG-ZEBOV-GP Ebola vaccine and key activities which are continuing to further expand our knowledge of the product. Extensive partnerships and innovative approaches were used to address the various challenges encountered during this process. The rVSVΔG-ZEBOV-GP Ebola vaccine was initially approved by the European Medicines Agency and prequalified by the World Health Organization in November 2019. It was approved by the United States Food and Drug Administration in December 2019 and approved in five African countries within 90 days of prequalification. The development resulted in the first stockpile of a registered Ebola vaccine that is available to support outbreak response. This also provides insights into how the example of rVSVΔG-ZEBOV-GP can inform the development of vaccines for Sudan ebolavirus, Marburg virus, and other emerging epidemic diseases in terms of the types of approaches and data needed to support product registration, availability, and the use of a filovirus vaccine.

Immunization funding across 28 European countries.

INTRODUCTION: Disease prevention and improving vaccination coverage in Europe are key elements contributing to resilient health systems and ensuring better health outcomes for all. The aim of this study was to describe the immunization funding landscape across all European Union 28 countries (EU28). AREAS COVERED: Data collected in a targeted literature review supported descriptive analysis on the different indicators that were looked at: vaccines included in the EU28 national immunization programs (NIP), national immunization funding, immunization funding per capita (2015-2019) and percentage of health-care budget allocated to immunization. EXPERT OPINION: Immunization funding represents a small proportion of total healthcare spend in Europe (median 0.3%). In the context of the current COVID-19 pandemic, demographic changes, and the potential introduction of new vaccines; the need for adequate financing of immunization programs will be important, to establish resilient immunization systems and provide sustainable protection of the population against vaccine-preventable diseases.

PLAIN LANGUAGE SUMMARYWhat is the context?Herpes zoster, or shingles, is a viral disease characterized by a painful, localized skin rash. It affects approximately 32% of US citizens at least once in their lifetime.The risk of contracting shingles increases with age.Most American adults over 50 years have not received the shingles vaccine, and vaccination rates are especially low for African-Americans.What is new?This is the first study to evaluate what drives shingles vaccination decisions among US adults ≥ 50 years of age. We also assessed the differences between African-American and non-African-American adults, and inside the African-American group.In this choice experiment, 1,454 people ≥ 50 years completed a survey of 8 choice questions, as well as questions on their previous experiences with vaccines, socioeconomic, and demographic characteristics. Seven factors were evaluated.We found that American adults preferred to get vaccinated, and the most influential factors were costs and vaccine effectiveness while location of vaccination was the least important. There were differences in preferences between African-American and non-African-American adults, mainly driven by costs and vaccine effectiveness. 3 different groups of African-American adults with systematically different preferences could be identified; two were likely to vaccinate, with one being more cost sensitive at lower price thresholds, and the third was unlikely to vaccinate.What is the impact?Decisions on shingles vaccination appear to be mostly driven by costs, which could be a barrier to those who do not have appropriate insurance, especially among some African-Americans.However, healthcare professionals should continue to educate patients on other vaccine characteristics, as they also influence vaccination decisions.

The status of human papillomavirus vaccination recommendation, funding, and coverage in WHO Europe countries (2018-2019).

Background: There is a need to better understand HPV vaccination (HPVv) implementation in WHO Europe Region (WHO/ER), including recommendations, funding, and vaccination coverage rates (VCR). Methods: A targeted literature review (up to 31 January 2020) was conducted using national health ministry websites, WHO database, and published studies from WHO/ER countries (n = 53). HPVv recommendations and funding data (target age, gender, schedule, setting, target and monitored VCR) for primary and catch-up cohorts were collected. Results: National recommendations for HPVv exist in 46/53 (87%) countries, of which 38 (83%), 2 (4%), and 6 (13%) countries provided full, partial, or no funding, respectively, for the primary cohort. Fully or partially funded HPVv was provided for girls only in 25/53 (47%) countries and for both boys and girls in 15/53 (28%) countries. HPVv catch-up was fully or partially funded in 14/53 (26%) countries. Among 40 countries with a national immunization program (NIP), monitored VCRs ranged from 4.3% to 99% (n = 30). Of the 10 countries reporting VCR targets, only Portugal exceeded its target. Conclusion: Of the 53 WHO/ER countries, 40 have funded HPVv NIPs, among which 30 report VCRs. Additional efforts are required to ensure HPVv NIPs are fully funded and high VCRs maintained.

Estimation of the individual residual risk of cervical cancer after vaccination with the nonavalent HPV vaccine.

BACKGROUND: The nonavalent HPV (9vHPV) vaccine is indicated for active immunisation of individuals from the age of 9 years against cervical, vulvar, vaginal and anal premalignant lesions and cancers causally related to vaccine HPV high risk types 16, 18, 31, 33, 45, 52 and 58, and to the HPV low risk types 6 and 11, causing genital warts. OBJECTIVE: To estimate the lifetime risk (up to the age of 75 years) for developing cervical cancer after vaccinating a HPV naïve girl (e.g. 9 to 12 years old) with the 9vHPV vaccine in the hypothetical absence of cervical cancer screening. METHODS: We built Monte Carlo simulation models using historical pre-screening age-specific cancer incidence data and current mortality data from Denmark, Finland, Norway, Sweden and the UK. Estimates of genotype contribution fractions and vaccine efficacy were used to estimate the residual lifetime risk after vaccination assuming lifelong protection. RESULTS: We estimated that, in the hypothetical absence of cervical screening and assuming lifelong protection, 9vHPV vaccination reduced the lifetime cervical cancer and mortality risks 7-fold with a residual lifetime cancer risks ranging from 1/572 (UK) to 1/238 (Denmark) and mortality risks ranging from 1/1488 (UK) to 1/851 (Denmark). After decades of repetitive cervical screenings, the lifetime cervical cancer and mortality risks was reduced between 2- and 4-fold depending on the country. CONCLUSION: Our simulations demonstrate how evidence can be generated to support decision-making by individual healthcare seekers regarding cervical cancer prevention.

Early direct and indirect impact of quadrivalent HPV (4HPV) vaccine on genital warts: a systematic review.

INTRODUCTION: Since 2007, many countries have implemented national human papillomavirus (HPV) vaccination programs with the quadrivalent HPV (4HPV) vaccine that has been shown to be efficacious in clinical trials involving 25,000 subjects. Two vaccine serotypes, HPV16 and 18, are responsible for cervical cancer and other HPV-related cancers, but the impact of the 4HPV vaccine on these cancers cannot be seen immediately as there is a considerable lag between infection with HPV and cancer development. The other two serotypes, HPV6 and 11, are responsible for genital warts (GWs), which develop within a few months after infection, making GWs an early clinical endpoint for the assessment of the impact of 4HPV vaccination. METHODS: We performed a systematic literature search in PubMed to identify all published studies on 4HPV vaccination, including those that assessed the impact of 4HPV vaccination programs on the incidence of GWs at a population level around the world. RESULTS: A total of 354 records were identified in the PubMed search. After screening and obtaining full papers for 56 publications, 16 publications presenting data on the impact or effectiveness of 4HPV vaccination on GWs were identified. These reported data on the impact or effectiveness of 4HPV in six countries [Australia (n = 6), New Zealand (n = 2), United States (n = 3), Denmark (n = 2), Germany (n = 1), and Sweden (n = 2)]. In Australia, no GWs were diagnosed in women aged <21 years who reported being vaccinated. A 92.6% reduction in GWs incidence was reported for all women in this age group, where the vaccine uptake rate (VUR) was 70% for 3 doses. The highest reductions were reported in countries with high VURs, mostly through school-based vaccination programs, although high VURs were obtained with some non-school-based programs. CONCLUSION: The results are coherent with the GWs incidence reduction reported in clinical trials and are an early indicator of what can be expected for the long-term clinical impact on vaccine-type HPV-related cancers.

An Overview of Quadrivalent Human Papillomavirus Vaccine Safety: 2006 to 2015.

BACKGROUND: A quadrivalent human papillomavirus (HPV4) type 6/11/16/18 vaccine (GARDASIL/SILGARD®) has been licensed in many countries around the world for the prevention of cervical, vulvar, vaginal, and anal cancers and precancers, as well as external genital warts causally related to HPV types 6/11/16/18. Across 7 phase 3 clinical trials involving more than 29,000 males and females ages 9-45 years, vaccination was generally well tolerated. Because of its expected public health benefit in reducing cervical cancer and other HPV-related diseases, the vaccine has been implemented in the national vaccination programs of several countries, with over 178 million doses distributed worldwide. METHODS: Extensive efforts to assess the safety of the vaccine in routine practice have been conducted over the past 9 years since licensure, including more than 15 studies in more than 1 million preadolescents, adolescents and adults from various countries. Most have been performed in the general population although there have been some in special populations (pregnant women, HIV-infected individuals and those with systemic lupus erythematosus). RESULTS: We present a summary of the published, postlicensure safety data from active and passive surveillance. Only syncope, and possibly skin infections were associated with vaccination in the postlicensure setting. Serious adverse events, such as adverse pregnancy outcomes, autoimmune diseases (including Guillain-Barre Syndrome and multiple sclerosis), anaphylaxis, venous thromboembolism and stroke, were extensively studied, and no increase in the incidence of these events was found compared with background rates. CONCLUSIONS: These results, along with the safety data from the prelicensure clinical trials, confirm that the HPV4 vaccine has a favorable safety profile. Key policy, medical and regulatory organizations around the world have independently reviewed these data and continue to recommend routine HPV vaccination.

DNA vaccines encoding retrovirus-based virus-like particles induce efficient immune responses without adjuvant.

Virus-like particle (VLP)-based vaccines have provided highly encouraging results in clinical trials while, in contrast, DNA vaccines expressing non-particulate proteins have proven less successful. Seeking to combine the immunogenicity of VLPs and the ease of production of plasmid DNA, we designed DNA vaccines expressing VLPs consisting of the MLV Gag and modified MLV Env proteins displaying T cell epitopes. We show here that such DNA vaccines are remarkably efficient immunogens for inducing cellular immune responses. In contrast to similar plasmids harboring a point mutation preventing VLP formation, they induce protection against a lethal viral challenge in mice. Thus, these "plasmo-retroVLPs" represent a promising second-generation DNA vaccine.

Targeted retroviral vectors displaying a cleavage site-engineered hemagglutinin (HA) through HA-protease interactions.

We report here a targeting method that exploits the expression pattern of cell surface proteases to induce gene delivery to specific tissues. We describe retroviral vectors harboring modified surface glycoproteins derived from an avian influenza virus hemagglutinin (HA) for which the cell entry properties, dependent on HA cleavage by producer cells, were conditionally blocked at a postbinding step by insertion of matrix metalloproteinase (MMP) substrates. We demonstrate that such vectors induce gene transfer, both in vitro and in mice harboring human tumor xenografts, only through contact with target cells expressing MMPs that cleave the substrate introduced into the recombinant HA. This selective gene transfer in MMP-rich cells was specifically inhibited by 1,10-phenanthroline, a broad-range MMP inhibitor. Importantly, such MMP-activatable vectors selectively transduced MMP-rich cells in heterogeneous populations containing MMP-rich and MMP-poor cells. These vectors will allow useful gene transfer applications into target cells exhibiting specific protease activities.