Safety Profile of the 9-Valent HPV Vaccine: A Combined Analysis of 7 Phase III Clinical Trials

Safety of Human Papillomavirus Vaccines: An Updated Review

Human papillomavirus (HPV) vaccines are now included in immunisation programmes in 71 countries. Unfortunately, uptake has been impacted in some countries by reduced confidence in the safety of the HPV vaccine. In 2013, we published an extensive review demonstrating a reassuring safety profile for bivalent (2vHPV) and quadrivalent (4vHPV) vaccines. A nonavalent (9vHPV) vaccine is now available and HPV immunisation programmes have been extended to males in 11 countries. The aim of this updated narrative review was to examine the evidence on HPV vaccine safety, focusing on the 9vHPV vaccine, special populations and adverse events of special interest (AESI). The previous searches were replicated to identify studies to August 2016, including additional search terms for AESI. We identified 109 studies, including 15 population-based studies in over 2.5 million vaccinated individuals across six countries. All vaccines demonstrated an acceptable safety profile; injection-site reactions were slightly more common for 9vHPV vaccine than for 4vHPV vaccine. There was no consistent evidence of an increased risk of any AESI, including demyelinating syndromes or neurological conditions such as complex regional pain or postural orthostatic tachycardia syndromes. The risk-benefit profile for HPV vaccines remains highly favourable.

Maternal transfer of anti HPV 6 and 11 antibodies upon immunization with the 9-valent HPV vaccine

BACKGROUND

This exploratory analysis was conducted to characterize the level of HPV types 6/11 antibodies in peripartum maternal blood and in cord blood of infants born to women who received 9-valent HPV (9vHPV) vaccine or quadrivalent HPV (qHPV) vaccine in a pivotal efficacy study (V503-001, NCT 00543543).

METHODS

A total of 21 mother-infant pairs had evaluable HPV 6/11 results available for analysis. HPV6/11 antibodies were assessed using competitive Luminex immunoassay. The distribution of the ratios of infant to mother anti-HPV antibodies (i.e., infant-anti-HPV/mother- anti-HPV) was summarized.

RESULTS

All mothers and infants were seropositive to HPV 6 and HPV 11. Anti-HPV 6/11 geometric mean titers (GMTs) in peripartum maternal blood and in cord blood of infant born to study participants were highly correlated. A 100% of infants born to seropositive mothers were also seropositive. The GMT ratios of peripartum maternal blood vs. those in cord blood were HPV 6: 1.23 [0.43, 3.49] and HPV 11: 1.29 [0.54, 3.07] in the 9vHPV vaccine group and HPV 6: 1.33 [0.41, 4.29] and HPV 11: 1.19 [0.45, 3.13] in the qHPV vaccine group, respectively.

CONCLUSIONS

These results indicate that antibodies induced by the 9vHPV vaccine cross the placenta, which could potentially be beneficial against HPV6/11 infection and related disease such as recurrent respiratory papillomatosis.

Evaluating the impact of multilevel evidence-based implementation strategies to enhance provider recommendation on human papillomavirus vaccination rates among an empaneled primary care patient population: a study protocol for a stepped-wedge cluster randomized trial

Background

Each year, human papillomavirus (HPV) causes 30,000 cancers in the USA despite the availability of effective and safe vaccines. Uptake of HPV vaccine has been low and lags behind other adolescent vaccines. This protocol describes a multilevel intervention to improve HPV vaccination rates.

Methods

Using a cluster randomized trial, we will evaluate the independent and combined impact of two evidence-based implementation strategies with innovative enhancements on HPV vaccination rates for female and male patients. The clusters are six primary care sites providing care to pediatric populations. We will use a stepped-wedge cluster randomized design, including process evaluation, to test the hypothesis that compared with the current course of care and a practice-level intervention using reminder-recall interventions coupled with provider-level audit and feedback with education increases HPV vaccination rates in exposed clusters. The factorial design allows us to use a single trial to test these two interventions and to assess each individually and in combination. Our design has four 12-month steps. The first step will be a baseline period; data collected during it will provide a within-practice control group for each cluster. Second, two clusters will be randomly assigned to receive intervention 1 (reminder and recall), and two clusters will be randomly selected to receive intervention 2 (audit and feedback with education). Third, the other two clusters will be randomly allocated to intervention 1 or 2. Clusters initially with intervention 1 will be randomly allocated to 1 + 2 or 1; clusters initially with intervention 2 will be randomly allocated to 1 + 2 or 2. Fourth, all clusters will receive both interventions. To ensure balance of patient numbers across interventions, we will use block randomization at the first step, with the six clusters grouped into three pairs according to volume. Our primary outcome will be vaccination rates.

Discussion

Results of our clinical trial and process evaluation will provide evidence showing whether practice- and provider-level interventions improve HPV vaccination rates and will offer insight into contextual factors associated with direction and magnitude of trial outcomes.

Trial registration

ClinicalTrials.gov, NCT03501992, registered April 18, 2018.

Electronic supplementary material

The online version of this article (10.1186/s13012-018-0778-x) contains supplementary material, which is available to authorized users.

Efficacy, immunogenicity, and safety of a 9-valent human papillomavirus vaccine in Latin American girls, boys, and young women

BACKGROUND

A 9-valent human papillomavirus (HPV6/11/16/18/31/33/45/52/58; 9vHPV) vaccine was developed to expand coverage of the previously developed quadrivalent (HPV6/11/16/18; qHPV) vaccine.

METHODS

Efficacy, immunogenicity, and safety outcomes were assessed in Latin American participants enrolled in 2 international studies of the 9vHPV vaccine, including a randomized, double-blinded, controlled with qHPV vaccine, efficacy, immunogenicity, and safety study in young women aged 16-26 years, and an immunogenicity and safety study in girls and boys aged 9-15 years. Participants (N=5312) received vaccination at Day 1, Month 2, and Month 6. Gynecological swabs were collected regularly in young women for cytological and HPV DNA testing. Serum was analyzed for HPV antibodies in all participants. Adverse events (AEs) were also monitored in all participants.

RESULTS

The 9vHPV vaccine prevented HPV 31-, 33-, 45-, 52-, and 58-related high-grade cervical, vulvar, and vaginal dysplasia with 92.3% efficacy (95% confidence interval 54.4, 99.6). Anti-HPV6, 11, 16, and 18 geometric mean titers at Month 7 were similar in the 9vHPV and qHPV vaccination groups. Anti-HPV antibody responses following vaccination were higher among girls and boys than in young women. Most (>99%) 9vHPV vaccine recipients seroconverted for all 9 HPV types at Month 7. Antibody responses to the 9 HPV types persisted over 5 years. The most common AEs were injection-site related, mostly of mild to moderate intensity.

CONCLUSIONS

The 9vHPV vaccine is efficacious, immunogenic, and well tolerated in Latin American young women, girls, and boys. These data support 9vHPV vaccination programs in Latin America, a region with substantial cervical cancer burden.

Invited Commentary: Moving From Evidence to Impact for Human Papillomavirus Vaccination-The Critical Role of Translation and Communication in Epidemiology

In response to the accompanying article by Yih et al. (Am J Epidemiol. 2018;187(6):1269-1276), we highlight the importance of moving beyond epidemiologic research on human papillomavirus (HPV) vaccine safety to focus on translation of this strong evidence base into successful vaccine safety communication strategies to bolster vaccine uptake. The potential of the HPV vaccine to reduce cancer incidence is substantial, yet actual HPV vaccination rates in the United States are disappointingly low in comparison with other routine childhood vaccines with similar safety profiles. This is no doubt due, in part, to persistent parental safety concerns. In 2016, safety remained the second most common reason for lack of vaccination intent by parents of unvaccinated adolescents. While the strong study by Yih et al. makes use of a novel statistical method and a large medical claims database to confirm the low occurrence of adverse events following HPV vaccination observed globally, their study also highlights a key challenge for epidemiologists: translating our research findings to other public health domains, so that evidence-informed communication strategies can be used to disseminate the information in a way that is understandable and useful to the public. Moving forward, multidisciplinary research teams will be essential to ensure that our epidemiologic findings have a broad public health impact.

Ten Years of Human Papillomavirus Vaccination in the United States

Since human papillomavirus (HPV) vaccine was first introduced for females in the United States in 2006, vaccination policy has evolved as additional HPV vaccines were licensed and new data became available. The United States adopted a gender neutral routine HPV immunization policy in 2011, the first country to do so. Vaccination coverage is increasing, although it remains lower than for other vaccines recommended for adolescents. There are various reasons for low coverage, and efforts are ongoing to increase vaccine uptake. The safety profile of HPV vaccine has been well established from 10 years of postlicensure monitoring. Despite low coverage, the early effects of the HPV vaccination program have exceeded expectations.

Association between Human Papilloma Virus (HPV) vaccination and risk of Multiple Sclerosis: A systematic review

INTRODUCTION

The vaccination against Humanpapilloma Virus (HPV) is an effective strategy to prevent high-risk HPV infection and subsequent cervical carcinogenesis. Although the safety profile has been ascertained, the relation with the development of central nervous system (CNS) autoimmune disorders (AD) appears still controversial. Multiple Sclerosis (MS) is the most common cause of chronic neurological impairment in young people, typically striking females. The main purpose of this review was to assess the association between HPV vaccination and MS.

METHODS

The systematic review of the literature was carried out using 5 search engines: MEDLINE, SCOPUS, ISI WEB OF KNOWLEDGE, GOOGLE SCHOLAR and ClinicalTrial.gov. The web search was updated on January 2017. PRISMA checklist was adopted to address the content of the systematic review. The measures of outcome were reported as relative risk (RR) in cohort studies and odds ratio (OR) in case-control studies.

RESULTS

The systematic review identified 5 observational studies, 9 reviews, and 1 randomized clinical trials (RCT) pooled analysis. The RR of MS onset detected by cohort studies ranged from 1.54 (95%CI, 0.04-8.59) to 1.37 (95%CI, 0.74-3.20). Concerning case-control studies, the OR spanned from 0.3, (95%CI 0.1-0.9) to 1.60 (95%CI = 0.79-3.25) for the group exposed to HPV vaccination. No result was significant.

CONCLUSION

This review showed no significant association between HPV vaccination and MS. The low statistical power of the studies agreed with the low incidence of MS disease among general population. In order to overcome the shortcoming the research may be extended to the entire pattern of CNS ADs.

Safety profile of the 9-valent human papillomavirus vaccine: assessment in prior quadrivalent HPV vaccine recipients and in men 16 to 26 years of age

A 9-valent HPV (9vHPV) vaccine has been developed to protect against HPV type 6/11/16/18/31/33/45/52/58-related infection and disease. Previous safety analyses from 7 clinical trials conducted in 9vHPV vaccine recipients 9–26 years of age, including comparisons of 9vHPV and quadrivalent HPV (qHPV) vaccines in girls and women 16–26 years of age, showed that the 9vHPV vaccine was generally well tolerated. Additional safety analyses were conducted to include the results of new clinical studies. The safety profile of the 9vHPV vaccine in prior qHPV vaccine recipients (n = 3756 from 1 randomized controlled trial and 2 open-label extension studies) and young men (n = 248 9vHPV and n = 248 qHPV vaccine recipients from 1 randomized controlled trial) was evaluated. Vaccine was administered as a 3-dose regimen (at Day 1 and Months 2 and 6), and adverse events (AEs) were monitored. The most common AEs were injection-site events (91.1% and 79.0% in prior qHPV vaccine recipients and young men, respectively), the majority of which were mild. Discontinuations due to an AE were rare (0.2% and 0.0% among prior qHPV vaccine recipients and young men, respectively). In young men, the AE profile of the 9vHPV vaccine was generally similar to that of the qHPV vaccine. Overall, the 9vHPV vaccine was generally well tolerated in prior qHPV vaccine recipients and in young men, with an AE profile generally consistent with that previously reported with the broader clinical program.

Final efficacy, immunogenicity, and safety analyses of a nine-valent human papillomavirus vaccine in women aged 16-26 years: a randomised, double-blind trial

BACKGROUND

Primary analyses of a study in young women aged 16-26 years showed efficacy of the nine-valent human papillomavirus (9vHPV; HPV 6, 11, 16, 18, 31, 33, 45, 52, and 58) vaccine against infections and disease related to HPV 31, 33, 45, 52, and 58, and non-inferior HPV 6, 11, 16, and 18 antibody responses when compared with quadrivalent HPV (qHPV; HPV 6, 11, 16, and 18) vaccine. We aimed to report efficacy of the 9vHPV vaccine for up to 6 years following first administration and antibody responses over 5 years.

METHODS

We undertook this randomised, double-blind, efficacy, immunogenicity, and safety study of the 9vHPV vaccine study at 105 study sites in 18 countries. Women aged 16-26 years old who were healthy, with no history of abnormal cervical cytology, no previous abnormal cervical biopsy results, and no more than four lifetime sexual partners were randomly assigned (1:1) by central randomisation and block sizes of 2 and 2 to receive three intramuscular injections over 6 months of 9vHPV or qHPV (control) vaccine. All participants, study investigators, and study site personnel, laboratory staff, members of the sponsor's study team, and members of the adjudication pathology panel were masked to vaccination groups. The primary outcomes were incidence of high-grade cervical disease (cervical intraepithelial neoplasia grade 2 or 3, adenocarcinoma in situ, invasive cervical carcinoma), vulvar disease (vulvar intraepithelial neoplasia grade 2/3, vulvar cancer), and vaginal disease (vaginal intraepithelial neoplasia grade 2/3, vaginal cancer) related to HPV 31, 33, 45, 52, and 58 and non-inferiority (excluding a decrease of 1·5 times) of anti-HPV 6, 11, 16, and 18 geometric mean titres (GMT). Tissue samples were adjudicated for histopathology diagnosis and tested for HPV DNA. Serum antibody responses were assessed by competitive Luminex immunoassay. The primary evaluation of efficacy was a superiority analysis in the per-protocol efficacy population, supportive efficacy was analysed in the modified intention-to-treat population, and the primary evaluation of immunogenicity was a non-inferiority analysis. The trial is registered with ClinicalTrials.gov, number NCT00543543.

FINDINGS

Between Sept 26, 2007, and Dec 18, 2009, we recruited and randomly assigned 14 215 participants to receive 9vHPV (n=7106) or qHPV (n=7109) vaccine. In the per-protocol population, the incidence of high-grade cervical, vulvar and vaginal disease related to HPV 31, 33, 45, 52, and 58 was 0·5 cases per 10 000 person-years in the 9vHPV and 19·0 cases per 10 000 person-years in the qHPV groups, representing 97·4% efficacy (95% CI 85·0-99·9). HPV 6, 11, 16, and 18 GMTs were non-inferior in the 9vHPV versus qHPV group from month 1 to 3 years after vaccination. No clinically meaningful differences in serious adverse events were noted between the study groups. 11 participants died during the study follow-up period (six in the 9vHPV vaccine group and five in the qHPV vaccine group); none of the deaths were considered vaccine-related.

INTERPRETATION

The 9vHPV vaccine prevents infection, cytological abnormalities, high-grade lesions, and cervical procedures related to HPV 31, 33, 45, 52, and 58. Both the 9vHPV vaccine and qHPV vaccine had a similar immunogenicity profile with respect to HPV 6, 11, 16, and 18. Vaccine efficacy was sustained for up to 6 years. The 9vHPV vaccine could potentially provide broader coverage and prevent 90% of cervical cancer cases worldwide.

FUNDING

Merck & Co, Inc.

9-Valent human papillomavirus vaccine: a review of the clinical development program

INTRODUCTION

The 9-valent human papillomavirus (9vHPV) vaccine covers the same HPV types (6/11/16/18) as the quadrivalent HPV (qHPV) vaccine and 5 additional cancer-causing types (31/33/45/52/58). Epidemiological studies indicate that the 9vHPV vaccine could prevent approximately 90% of cervical cancers, 70-85% of high-grade cervical dysplasia (precancers), 85-95% of HPV-related vulvar, vaginal, and anal cancers, and 90% of genital warts. Areas covered: Study design features and key findings from the 9vHPV vaccine clinical development program are reviewed. In particular, 9vHPV vaccine efficacy was established in a Phase III study in young women age 16-26 years. Efficacy results in young women were extrapolated to pre- and young adolescent girls and boys and young men by immunological bridging (i.e., demonstration of non-inferior immunogenicity in these groups versus young women). Expert commentary: The development of the 9vHPV vaccine is the outcome of 20 years of continuous clinical research. Broad vaccination programs could help substantially decrease the incidence of HPV-related disease.

Expanded strain coverage for a highly successful public health tool: Prophylactic 9-valent human papillomavirus vaccine

Human papillomavirus is considered the causative factor for cervical cancer, which accounts for approximately 5% of the global cancer burden and more than 600,000 new cases annually that are attributable to HPV infection worldwide. The first-generation prophylactic HPV vaccines, Gardasil® and Cervarix®, were licensed approximately a decade ago. Both vaccines contain the most prevalent high-risk types, HPV16 and 18, which are associated with 70% of cervical cancer. To further increase the type coverage, 5 additional oncogenic HPV types (31, 33, 45, 52 and 58) were added to the existing Gardasil-4 to develop a 9-valent HPV vaccine (9vHPV), Gardasil 9®, increasing the potential level of protection from ∼70% to ∼90%. The efficacy of the vaccine lies primarily in its ability to elicit type-specific and neutralizing antibodies to fend off the viral infection. Therefore, type-specific and neutralizing murine monoclonal antibodies (mAbs) were used to quantitate the antigenicity of the individual vaccine antigens and to measure the antibody levels in the serum samples from vaccinees in a type- and epitope-specific manner in a competitive immunoassay. Assays for 9vHPV are extended from the proven platform used for 4vHPV by developing and adding new mAbs against the additional types. In Phase III clinical trials, comparable safety profile and immunogenicity against the original 4 types were demonstrated for the 9vHPV vaccine, and these were comparable to the 4vHPV vaccine. The efficacy of the 9vHPV vaccine was established in trials with young women. Immunobridging for younger boys and girls was performed, and the results showed higher immunogenicity in the younger age group. In a subsequent clinical trial, the 2-dose regimen of the 9vHPV vaccine used among girls and boys aged 9-14 y showed non-inferior immunogenicity to the regular 3-dose regimen for young women (aged 16-26 years). Overall, the clinical data and cost-effectiveness analysis for the 9vHPV vaccine support its widespread use to maximize the impact of this important, life-saving vaccine.

HPV prevalence in vulvar cancer in Austria

Background

Even if vulvar cancer is not common, over one hundred women are affected in Austria per year. There is strong evidence that basaloid and warty variants are associated with types of human papillomavirus (HPV).

Methods

The aim of this study is to analyze the types of HPV in vulvar cancer in Austria. This cross-sectional period-prevalence international collaborative study on archival specimens was performed in cooperation with the Institut Catalan di Oncologia in Barcelona, Spain. A total of 177 consecutive samples of Austrian women were analyzed to detect the presence of various HPV types using the SPF10 PCR/DEIA/LiPA25 system. Furthermore, the expression of the tumor suppressor protein p16^INK4a was analyzed by immunohistochemistry (CINtec histology kit, ROCHE). A tumor was considered HPV-driven if an overexpression of p16^INK4a was detected.

Results

In all, 41 cases of vulvar cancer tested positive for HPV DNA (23%) and 32 (18%) were p16 positive. Patients with warty and basaloid squamous cell cancer were significantly younger than those with keratinizing squamous cell cancer (63.3 years vs. 71.0 years, p = 0.021). In addition, 77.4% of all cases suffering from warty or basaloid squamous cell cancer tested positive for HPV, compared to 9.5% of the keratinizing squamous cell cancer cases (p < 0.001). The most commonly detected HPV strain was type 16, followed by 31 and 33.

Conclusion

Infection with HPV type 16 appears to be strongly correlated to the development of warty or basaloid squamous cell cancer. Vaccination against HPV can be expected to prevent this type of vulvar cancer.

Progress in prophylactic human papillomavirus (HPV) vaccination in 2016: A literature review

Prophylactic human papillomavirus (HPV) vaccine represents a revolutionary step forward in preventing HPV-related cancers, especially cervical carcinoma. Alongside appropriate screening, it has the potential to dramatically reduce cervical cancer incidence and even eradicate it. Following extensive evaluations in clinical trials, the first decade of routine HPV vaccine use provides overwhelming evidence of the vaccines' safety and their real-life effectiveness. In 2016, further clinical trials showed high vaccine efficacy in adult women, especially those that were HPV DNA-negative at baseline, and indicated possible protection from HPV-related diseases after treatment of precancerous cervical lesions. The recommendation for a two-dose schedule in individuals under 15 is further supported for all three licensed vaccines by immunogenicity studies that show non-inferior immune responses and similar clinical efficacy compared to the three-dose schedule. So far, natural competition between HPV types has not been confirmed and therefore vaccine-induced clinically significant type replacement is unlikely. The real-world effectiveness data showed cross-sectional reduction in the prevalence/incidence of vaccine-related HPV types, genital warts and precancerous cervical lesions in countries and regions with HPV vaccination coverage. These declines were evident not only in vaccinated females, but also in unvaccinated females and males, strongly suggesting herd protection. Despite an excellent safety profile consistently demonstrated in clinical trials and confirmed in real-life settings, recently invented controversial syndromes allegedly linked to HPV vaccines temporarily compromised some previously very successful vaccination programs and significantly contributed to the failure of HPV vaccine implementation in some countries with the highest prevalence of cervical cancer. However, several safety studies failed to confirm any association of these syndromes with HPV vaccination in various settings and geographic locations. The main challenges remain implementing HPV vaccination in national vaccination programs, especially in low-and middle-income countries with the highest burden of cervical cancer, and achieving and sustaining high vaccine coverage rates.

Human papillomavirus first and second generation vaccines-current status and future directions

It has been more than 10 years that the first prophylactic papillomavirus vaccine became available, although distribution has been mainly limited to the more affluent countries. The first two vaccines have been a great success, hundreds of millions of women and a much smaller number of men have been vaccinated ever since. In a few countries with high vaccination coverage, in particular Australia but also parts of Great Britain and others, clinical impact of vaccination programs is already visible and there are indications for herd immunity as well. Vaccine efficacy is higher than originally estimated and the vaccines have an excellent safety profile. Gardasil9 is a second generation HPV virus-like particle vaccine that was licensed in 2015 and there are more to come in the near future. Currently, burning questions in respect to HPV vaccination are the duration of protection - especially in regard to cross-protection - reduction of the three-dose regimen and its impact on cross-protection; and duration of response, as well as protection against oropharyngeal HPV infections. Furthermore, researchers are seeking to overcome limitations of the VLP vaccines, namely low thermal stability, cost, invasive administration, limited coverage of non-vaccine HPV types, and lack of therapeutic efficacy. In this review we summarize the current status of licensed VLP vaccines and address questions related to second and third generation HPV vaccines.

Safety of Human Papillomavirus 9-Valent Vaccine: A Meta-Analysis of Randomized Trials

Vaccination against human papillomavirus (HPV) has been progressively implemented in most developed countries for approximately 10 years. In order to increase the protection of the vaccines, a 9-valent vaccine (HPV9) was developed, which provides protection against nine types of the virus. Studies evaluating its safety are rare. Thus, we performed a meta-analysis of three clinical trials assessing adverse effects on women randomly vaccinated with HPV9 or tetravalent vaccine (HPV4), with the objective of analyzing whether the HPV9 is as safe as HPV4. An electronic data search was performed through the PubMed, Embase, Scopus, Web of Science, and SciELO databases. The studies selected 27,465 women who received one of the two vaccines. Pain (OR 1.72; 95% CI 1.62–1.82) and erythema (OR 1.29; 95% CI 1.21–1.36) occurred significantly more in the HPV9 group. However, there was no significant difference between the groups for the following adverse effects: headache (OR 1.07; 95% CI 0.99–1.15), dizziness (OR 1.09; 95% CI 0.93–1.27), and fatigue (OR 1.09; 95% CI 0.91–1.30), and the occurrence of serious events related to vaccination was similarly rare among those vaccinated. Therefore, our findings demonstrate that HPV9 in female patients is as safe as the tetravalent vaccine.

Safety and perception: What are the greatest enemies of HPV vaccination programmes?

Vaccines stimulate a person's immune system to produce an adequate reaction against a specific infectious agent; i.e. the person is protected from that disease without having to get it first. As vaccines are administrated to healthy subjects, they are held to the highest standards of safety. Regarding human papillomavirus (HPV) vaccines, at present three prophylactic vaccines are licensed (bivalent HPV 16/18, quadrivalent HPV 6/11/16/18 and the nonovalent HPV 6/11/16/18/31/33/45/52/58 vaccine). Pre- and post-licensure studies (i.e. not yet for nonovalent HPV vaccine) confirm that HPV vaccines are generally safe and well-tolerated, site injections symptoms are the most common adverse events (AEs) reported, and pain is the most frequently referred local symptom. Serious AEs are rare and not associated with severe sequelae, at least no vaccine-related deaths have occurred. Despite these scientific evidences, it is still difficult to explain to the population the importance of a good vaccination programme. There are many determinants for HPV vaccines hesitancy which represent a barrier that must be overcome in order to increase vaccine coverage, including psychological reactions, religious or cultural aspects, and fear of possible AEs (demyelinating diseases, Complex Regional Pain Syndrome - CRPS, or Postural Orthostatic Tachycardia Syndrome - POTS). A weak communication strategy which frequently suffers due to spread of unverified news by media and websites may lead to the failure of a vaccination programme. Such a situation happened in Japan (2013), due to which a great number of women remain vulnerable to HPV-related cancers. In order to resolve the issues around HPV vaccines acceptance, it is necessary to use good communication strategies. Multicomponent and dialogue-based interventions seem to be the most effective, especially if an adequate language is used, customized according to the vaccination programme target.

Preventing human papillomavirus-related cancers: we are all in this together

Human papillomavirus-related cancers, which include cervical, vulvovaginal, anal, and oropharyngeal cancers, are on the rise in the United States. Although the human papillomavirus vaccine has been on the market for 10 years, human papillomavirus vaccination rates are well below national goals. Research identified many barriers and facilitators to human papillomavirus vaccination, and provider recommendation remains the most important factor in parental and patient decisions to vaccinate. While much of the burden of human papillomavirus vaccine provision falls on pediatricians and primary care providers, they cannot do it alone. As clinicians who care for a large proportion of human papillomavirus-related conditions, obstetrician-gynecologists and other women's health care providers must share the responsibility for vaccination of eligible patients. Obstetrician-gynecologists can support the efforts to eradicate human papillomavirus-related disease in their patients and their families via multiple avenues, including providing the human papillomavirus vaccine and being community leaders in support of vaccination.

[Human papillomavirus nonavalent vaccine. Update 2017]

Human papillomavirus (HPV) is the causative agent of 5% of human cancers. HPV infection is necessary for the development of cervical cancer and is responsible of a variable percentage of cancers of anus, vulva, vagina, penis, and oropharynx. Since 2007, 2 vaccines against HPV have been commercially available in Spain: bivalent (HPV types 16/18), and tetravalent (HPV types 6/11/16/18). In order to extend the protection afforded by HPV vaccines, a clinical program was launched in 2006 for the new nonavalent vaccine, including 9 HPV types (6/11/16/18/31/33/45/52/58). These types are responsible for 90% of cervical cancers, 82% of high-grade ano-genital pre-cancerous lesions, and 90% of genital warts. The purpose of this publication is to provide healthcare professionals with the scientific evidence that supports the new vaccine, as well as the clinical value that it offers in our environment.

Non-conventional expression systems for the production of vaccine proteins and immunotherapeutic molecules

The increasing demand for recombinant vaccine antigens or immunotherapeutic molecules calls into question the universality of current protein expression systems. Vaccine production can require relatively low amounts of expressed materials, but represents an extremely diverse category consisting of different target antigens with marked structural differences. In contrast, monoclonal antibodies, by definition share key molecular characteristics and require a production system capable of very large outputs, which drives the quest for highly efficient and cost-effective systems. In discussing expression systems, the primary assumption is that a universal production platform for vaccines and immunotherapeutics will unlikely exist. This review provides an overview of the evolution of traditional expression systems, including mammalian cells, yeast and E.coli, but also alternative systems such as other bacteria than E. coli, transgenic animals, insect cells, plants and microalgae, Tetrahymena thermophila, Leishmania tarentolae, filamentous fungi, cell free systems, and the incorporation of non-natural amino acids.