Quadrivalent human papillomavirus (HPV) types 6, 11, 16, 18 vaccine: for the prevention of genital warts in males

Ovine papillomavirus type 3 virus-like particle-based tools for diagnosis and detection of infection

The design of prophylactic and diagnostic tools specific to animal papillomaviruses is hampered by the difficulties of viral in vitro manipulation and by the scarce availability of dedicated biotechnological tools. This paper reports the production of Ovine Papillomavirus 3 (OaPV3)-based virus-like particles (OaPV3-VLPs) in the baculovirus system and their use to investigate host humoral immune response through the establishment of an indirect ELISA test., Polyclonal sera and monoclonal antibodies were generated against OaPV3-VLPs, and their isotype and reactivity were determined. Additionally, antibodies allowed OaPV3 detection in ovine squamous cell carcinoma (SCC) samples by immunohistochemistry. Results encourage the standardization of OaPV3-specific prophylactic and serological diagnostic tools, and open new perspectives for the study of host-viral interaction and SCC development.

Identifying Barriers to HPV Vaccination for Patients With Sickle Cell Disease and Childhood Cancer Survivors

Human papillomavirus (HPV) vaccination prevents the development of HPV-associated malignancies. Adolescent and young adult survivors of childhood cancers and patients with sickle cell disease (SCD) are vulnerable patient populations who would significantly benefit from HPV vaccination. In this multimethod study, a retrospective chart review found a notable difference between the rate of HPV vaccinations and other age-appropriate vaccinations in 177 childhood cancer survivors and in 70 patients with SCD. We then sought to describe patient and caregiver beliefs regarding HPV vaccination, through semistructured interviews with 21 patients and 48 caregivers. Interviews were analyzed with a thematic content approach to understand attitudes regarding the HPV vaccination. Qualitative interviews noted that many caregivers and adolescents had baseline misconceptions regarding the HPV vaccination in general and in context with their chronic illness. It was found that a strong recommendation from a trusted subspecialty provider would create reassurance about vaccination and reduce misconceptions and concerns about side effects in the context of a chronic illness. Counseling from subspecialists could have a strong impact on understanding the HPV vaccine in the context of chronic illness. This would likely help overcome many of the barriers to vaccination that are encountered by patients with SCD or oncology survivors.

Differences in HPV-specific antibody Fc-effector functions following Gardasil® and Cervarix® vaccination

Gardasil® (Merck) and Cervarix® (GlaxoSmithKline) both provide protection against infection with Human Papillomavirus 16 (HPV16) and Human Papillomavirus 18 (HPV18), that account for around 70% of cervical cancers. Both vaccines have been shown to induce high levels of neutralizing antibodies and are known to protect against progression beyond cervical intraepithelial neoplasia grade 2 (CIN2+), although Cervarix® has been linked to enhanced protection from progression. However, beyond the transmission-blocking activity of neutralizing antibodies against HPV, no clear correlate of protection has been defined that may explain persistent control and clearance elicited by HPV vaccines. Beyond blocking, antibodies contribute to antiviral activity via the recruitment of the cytotoxic and opsonophagocytic power of the immune system. Thus, here, we used systems serology to comprehensively profile Gardasil®- and Cervarix®- induced antibody subclass, isotype, Fc-receptor binding, and Fc-effector functions against the HPV16 and HPV18 major capsid protein (L1). Overall, both vaccines induced robust functional humoral immune responses against both HPV16 and HPV18. However, Cervarix® elicited higher IgG3 and antibody-dependent complement activating responses, and an overall more coordinated response between HPV16 and 18 compared to Gardasil®, potentially related to the distinct adjuvants delivered with the vaccines. Thus, these data point to robust Fc-effector functions induced by both Gardasil® and Cervarix®, albeit with enhanced coordination observed with Cervarix®, potentially underlying immunological correlates of post-infection control of HPV.

Can quadrivalent human papillomavirus prophylactic vaccine be an effective alternative for the therapeutic management of genital warts? an exploratory study

OBJECTIVE

To evaluate the treatment effect of genital warts, we investigated the quadrivalent HPV vaccine injection compared with surgical excision.

MATERIALS AND METHODS

This prospective study included 26 patients (M:F = 24:2) who received HPV vaccine or surgical excision. After explanation of surgical excision or HPV vaccine, 16 patients underwent surgical excision and the others received HPV vaccine injections. Based on gross findings of genital warts, treatment outcomes were classified as complete response (no wart), partial response, and failed treatment.

RESULTS

Among enrolled patients, 42% (11 / 26) patients had recurrent genital warts. In vaccination group, complete response rates of genital wart were 60% following 3 times HPV vaccine. Partial response patients wanted to excise the genital lesions before the 3 times injection, because they worried about sexual transmission of disease to their sexual partners. One patient underwent surgical excision after 3 times injection. Excision sites included suprapubic lesions, but other sites including mid-urethra and glans showed complete response after injection. At a mean follow-up period of 8.42 ± 3.27 months, 10 patients (100%) who received HPV vaccine did not show recurrence.

CONCLUSION

The response rates after HPV vaccine injection were 90% (complete and partial). Our results suggested that HPV vaccines could be effective in management of genital warts.

Carcinogenic human papillomavirus infection

Infections with human papillomavirus (HPV) are common and transmitted by direct contact. Although the great majority of infections resolve within 2 years, 13 phylogenetically related, sexually transmitted HPV genotypes, notably HPV16, cause - if not controlled immunologically or by screening - virtually all cervical cancers worldwide, a large fraction of other anogenital cancers and an increasing proportion of oropharyngeal cancers. The carcinogenicity of these HPV types results primarily from the activity of the oncoproteins E6 and E7, which impair growth regulatory pathways. Persistent high-risk HPVs can transition from a productive (virion-producing) to an abortive or transforming infection, after which cancer can result after typically slow accumulation of host genetic mutations. However, which precancerous lesions progress and which do not is unclear; the majority of screening-detected precancers are treated, leading to overtreatment. The discovery of HPV as a carcinogen led to the development of effective preventive vaccines and sensitive HPV DNA and RNA tests. Together, vaccination programmes (the ultimate long-term preventive strategy) and screening using HPV tests could dramatically alter the landscape of HPV-related cancers. HPV testing will probably replace cytology-based cervical screening owing to greater reassurance when the test is negative. However, the effective implementation of HPV vaccination and screening globally remains a challenge.

Safety of human papillomavirus vaccines: a review

INTRODUCTION

Between 2006 and 2009, two different human papillomavirus virus (HPV) vaccines were licensed for use: a quadrivalent (qHPVv) and a bivalent (bHPVv) vaccine. Since 2008, HPV vaccination programmes have been implemented in the majority of the industrialized countries. Since 2013, HPV vaccination has been part of the national programs of 66 countries including almost all countries in North America and Western Europe. Despite all the efforts made by individual countries, coverage rates are lower than expected. Vaccine safety represents one of the main concerns associated with the lack of acceptance of HPV vaccination both in the European Union/European Economic Area and elsewhere.

AREAS COVERED

Safety data published on bivalent and quadrivalent HPV vaccines, both in pre-licensure and post-licensure phase, are reviewed.

EXPERT OPINION

Based on the latest scientific evidence, both HPV vaccines seem to be safe. Nevertheless, public concern and rumors about adverse events (AE) represent an important barrier to overcome in order to increase vaccine coverage. Passive surveillance of AEs is an important tool for detecting safety signals, but it should be complemented by activities aimed at assessing the real cause of all suspect AEs. Improved vaccine safety surveillance is the first step for effective communication based on scientific evidence.

Childhood vaccination associated adverse events by sex: a literature review

BACKGROUND

Most approved medicines, including vaccines can be associated with adverse events. A vaccine adverse event is defined as any untoward medical occurrence which follows vaccination, but which does not necessarily have a causal relationship with the administration of the vaccine.

METHODS

The objective of this structured literature review is to analyse the adverse events reported with vaccinations usually done during childhood and adolescence: human papilloma virus vaccine, hepatitis B vaccine and measles-mumps-rubella vaccine. We evaluated the vaccine literature on children and adolescents by sex. We searched the Cochrane Database, Medline (Pubmed) and Embase using predefined terms.

RESULTS

Of the 417 publications retrieved from searches in the 3 databases, 89 papers (21%) were identified as potentially relevant to the review. On further scrutiny 41 of these satisfied the criteria for inclusion in the analysis. Serious adverse events related to vaccinations were rare. We found some possible sex related vaccine adverse events. Few trials however reported adverse events by age and sex and very few analyses evaluated the observed differences.

CONCLUSIONS

Despite earlier calls for sex-specific analyses of clinical studies, we found that vaccine trials were rarely reported and published by sex. Prospectively collated vaccine safety data in children and adolescents should be analysed by age and sex, so that clinical trial results can form an evidence base for vaccine practice recommendations.

HPV awareness and willingness to HPV vaccination among high-risk men attending an STI clinic in Puerto Rico

OBJECTIVE

An HPV vaccine has been approved for men aged 9 to 26 in the US for the prevention of genital warts and anal cancer. The purpose of this study is to describe 1) HPV vaccine awareness, 2) willingness to get the HPV vaccine and 3) perceived susceptibility to HPV-related cancers and genital warts among men 18-26 years old who attend an STI clinic in San Juan, Puerto Rico (PR).

METHODS

A cross-sectional pilot study consisting of 206 HIV+/HIV- men. For purpose of this analysis, only those participants aged <or=26 years old were included in this analysis (n=46).

RESULTS

None of the study participants had been vaccinated against HPV. Fewer than a third knew about the HPV vaccine (28.3%). However, more than half (76.9%) were willing to be vaccinated against HPV. Information sources about the HPV vaccine included their female sexual partners (13.0%), a female sexual partner who received the vaccine (8.7%) and a male sexual partner (2.2%). Most participants'reported that the main reason that would increase their willingness to get vaccinated was if a physician recommend the vaccine (95.7%). Perceived susceptibility was low, particularly for anal and oral cancer.

CONCLUSION

This pilot study shows poor awareness of the HPV vaccine, although willingness to getting the HPV vaccine was high among those who knew about the vaccine. Future studies should try to evaluate this paradox and study in depth willingness and barriers to vaccination among male sub-groups, such as men who have sex with men (MSM). These studies should also evaluate predictors of uptake of the HPV vaccine among men in this and other STI clinics in PR, in order to develop interventions to increase male vaccination.