Chapter 12: Prophylactic HPV vaccines: Underlying mechanisms

Prevalence of Human Papillomavirus (HPV) and HPV Type Distribution in Penile Samples in Young Men in Denmark: Results 10 Years After Implementation of a Girls-Only HPV Vaccination Program

BACKGROUND

In Denmark, a girls-only human papillomavirus (HPV) vaccination program was initiated in 2008-2009. The study aim was to assess the HPV prevalence and type distribution in younger men prior to HPV vaccination in men.

METHODS

The study population was younger men who attended information days regarding military service. At random days (2019-2020), 280 men were included. We collected questionnaire data regarding risk factors for HPV infection and a penile swab for HPV testing. We compared results in this study with those from a previous study of young men (2006-2007).

RESULTS

The majority of participants (94%) were 18-20 years old. The median number of lifetime sexual partners was 4. Altogether, 130 men (46.4%) were HPV positive. No infections with HPV types 6, 11, 16, 18, 31, and 45 were detected. The most frequent type was HPV-51 (detected in 11.1%). Comparison showed that the odds of high-risk HPV type infection were higher in 2019-2020 (prevalence odds ratio [POR], 1.7 [95% confidence interval {CI}, 1.1-2.7]) compared with 2006-2007. In contrast, the odds were lower (POR, 0.3 [95% CI, .1-.6]) for HPV types targeted by the 9-valent HPV vaccine.

CONCLUSIONS

The multicohort girls-only vaccination program has to a large degree protected young men against the HPV types included in the licensed vaccines. This does not speak against gender-neutral vaccination as the HPV prevalence is still high, although consisting largely of less carcinogenic HPV types.

Genetic diversity, variation and recombination among the human papillomaviruses (HPVs) genomes isolated in China: a comparative genomic and phylogenetic analysis

Human papillomaviruses (HPVs) are widespread, sexually transmitted group of viruses that infect most individuals at some stage, causing genital warts and cancers. They are members of the Papillomaviridae family, which contains about 400 HPV types. China is among the high HPV burden countries with reported infections of multiple HPV types, accounting for 17.3% of global deaths and 18.2% of global new cases. Thus, understanding the genetic variation and geographic diversity characteristics of HPVs isolated in China is critical for global HPV prevention strategies. Thus, we analyzed the available HPV genome sequences isolated in China that grouped into two categories (alpha- and gamma-papillomaviruses) based on full-length genomes. The most common were HPV-16, -6, -58, and -52 respectively. In addition, four of the novel strains isolated in China, e.g. TG550, JDFY01, CH2, and L55 clustered with the HPV-mSK 159, 244, 201, and 200 respectively. Our phylogeographic network analysis indicated that the L55, TG550, and CH2 are genetically identical to the mSK 200, 046, and 201 respectively, while JDFY01 appeared separately, connected to the mSK-040 following five mutational steps. Also, we found ten recombination events among HPV-6/11 types within their E1, E2, E7, L1/L2 proteins, and Long Control Region ORFs. We achieved the consensus amino acid sequences of HPV proteins and found a conserved stretch of amino acids within E5A of all HPVs circulating in China. These findings offer valued insights into the genetic relationships, distribution, and evolution of the HPVs in China that may assist in adapting effective HPV preventive measures.

A validated polyclonal antiserum-based immunoassay for assessment of HPV 16 L1 relative potency

Vaccine potency is typically evaluated using an assay that acts as a surrogate for biological activity. Although in vivo vaccines better represent human immunological responses, in vitro assays are preferred due to lower variability, higher throughput, easier validation and ethical considerations. In in vitro determination of Human Papillomavirus (HPV), Virus-like particle (VLP) vaccine potency currently depends on monoclonal antibody assays. However, these reagents are hard to obtain and currently are not available commercially. In this work, a polyclonal antiserum-based immunoassay was developed to evaluate the relative potency of Alhydrogel formulated HPV 16 VLPs. The repeatability and specificity were evaluated, and found that the assay was sensitive to small amounts of non-VLP HPV 16 L1 proteins. Finally, the assay was tested in comparison to the mouse effective dose 50 (ED50) assay on a limited number of batches. The agreement between these results suggests this test as a suitable surrogate for the in vivo test.

[HPV vaccinations and cervical cancer in Japan: Flaws in alleged experimental evidence for molecular mimicry and animal models of HPV vaccine-induced "adverse reactions "]

In Japan, around 3,000 females have died of cervical cancer annually. Cervical cancer is caused by sexually transmitted infections of the human papillomavirus (HPV); it is preventable by vaccinations against oncogenic HPV types, such as types 16 and 18. In Japan, the proactive recommendations for HPV vaccinations were suspended in June 2013 due to public concerns about neuropsychological "diverse symptoms" following HPV vaccinations. The suspension resulted in the vaccination rate less than 1% among the eligible population. In April 2022, the Japanese government resumed the proactive HPV vaccination recommendations after 9 years of the suspension. Many Japanese people, however, still have concerns about the "diverse symptoms" as adverse reactions following HPV vaccinations. In this article, we critically evaluated the manuscripts cited in the HPV vaccine lawsuits in Japan, including computational and animal studies, which have been used as the theoretical basis for how HPV vaccinations could induce the "diverse symptoms." We concluded that all the manuscripts had scientific flaws, which should not be used to prove that HPV vaccinations could induce the adverse reactions. We wish that our current evaluation would contribute to eliminating baseless concerns about HPV vaccines, eventually increasing the rate of HPV vaccinations in Japan.

Immunogenicity and safety of an Escherichia coli-produced human papillomavirus (types 6/11/16/18/31/33/45/52/58) L1 virus-like-particle vaccine: a phase 2 double-blind, randomized, controlled trial

The Escherichia coli-produced human papillomavirus (HPV) 16/18 bivalent vaccine (Cecolin) has received prequalification by the World Health Organization based on its high efficacy and good safety profile. We aimed to evaluate the immunogenicity and safety of the second-generation nonavalent HPV 6/11/16/18/31/33/45/52/58 vaccine (Cecolin 9) through the randomized, blinded phase 2 clinical trial. Eligible healthy women aged 18-45 years were randomly (1:1) allocated to receive three doses of 1.0 mL (270 µg) of Cecolin 9 or placebo with a 0-1-6-month schedule. The primary endpoint was the seroconversion rate and geometric mean titer of neutralizing antibodies (nAbs) one month after the full vaccination course (month 7). The secondary endpoint was the safety profile including solicited adverse reactions occurring within 7 d, adverse events (AEs) occurring within 30 d after each dose, and serious adverse events (SAEs) occurring during the 7-month follow-up period. In total, 627 volunteers were enrolled and randomly assigned to Cecolin 9 (n = 313) or placebo (n = 314) group in Jiangsu Province, China. Almost all participants in the per-protocol set for immunogenicity (PPS-I) seroconverted for nAbs against all the nine HPV types at month 7, while two failed to seroconvert for HPV 11 and one did not seroconvert for HPV 52. The incidence rates of total AEs in the Cecolin 9 and placebo groups were 80.8% and 72.9%, respectively, with the majority of them being mild and recovering shortly. None of the SAEs were considered related to vaccination. In conclusion, the E. coli-produced 9-valent HPV (9vHPV) vaccine candidate was well tolerated and immunogenic, which warrants further efficacy studies in larger populations.

A systematic review on the molecular and clinical association between Human Papillomavirus and Human Immunodeficiency Virus co-infection in Head, Neck and Oral squamous cell carcinoma

Head and neck cancer, one of the most commonly prevalent malignancies globally is a complex category of tumours that comprises cancers of the oral cavity, pharynx, and larynx. A specific subgroup of such cancers has been found with some unique chromosomal, therapeutic, and epidemiologic traits with the possibility of affecting via co-infection. About 25% of all head and neck cancers in the population are human papillomavirus infection (HPV)-associated, typically developing in the oropharynx, which comprises the tonsils. In the period of efficient combined antiviral treatment, HPV-positive oral cancers are also becoming a significant contributor to illness and fatality for Human Immunodeficiency Virus (HIV)-infected persons. Although the prevalence and historical background of oral HPV transmission are not thoroughly understood, it seems likely that oral HPV transmission is relatively frequent in HIV-infected people when compared to the overall population. Therefore, there is a need to understand the mechanisms leading to this co-infection, as there is very little research related to that. Hence, this study mainly focus on the therapeutical and biomedical analysis of HPV and HIV co-infection in the above-mentioned cancer, including oral squamous cell carcinoma.

Onco-Pathogen Mediated Cancer Progression and Associated Signaling Pathways in Cancer Development

Infection with viruses, bacteria, and parasites are thought to be the underlying cause of about 8-17% of the world's cancer burden, i.e., approximately one in every five malignancies globally is caused by an infectious pathogen. Oncogenesis is thought to be aided by eleven major pathogens. It is crucial to identify microorganisms that potentially act as human carcinogens and to understand how exposure to such pathogens occur as well as the following carcinogenic pathways they induce. Gaining knowledge in this field will give important suggestions for effective pathogen-driven cancer care, control, and, ultimately, prevention. This review will mainly focus on the major onco-pathogens and the types of cancer caused by them. It will also discuss the major pathways which, when altered, lead to the progression of these cancers.

Human papillomavirus genomics: Understanding carcinogenicity

Human papillomavirus (HPV) causes virtually all cervical cancers and many cancers at other anatomical sites in both men and women. However, only 12 of 448 known HPV types are currently classified as carcinogens, and even the most carcinogenic type - HPV16 - only rarely leads to cancer. HPV is therefore necessary but insufficient for cervical cancer, with other contributing factors including host and viral genetics. Over the last decade, HPV whole genome sequencing has established that even fine-scale within-type HPV variation influences precancer/cancer risks, and that these risks vary by histology and host race/ethnicity. In this review, we place these findings in the context of the HPV life cycle and evolution at various levels of viral diversity: between-type, within-type, and within-host. We also discuss key concepts necessary for interpreting HPV genomic data, including features of the viral genome; events leading to carcinogenesis; the role of APOBEC3 in HPV infection and evolution; and methodologies that use deep (high-coverage) sequencing to characterize within-host variation, as opposed to relying on a single representative (consensus) sequence. Given the continued high burden of HPV-associated cancers, understanding HPV carcinogenicity remains important for better understanding, preventing, and treating cancers attributable to infection.

B Cell Responses upon Human Papillomavirus (HPV) Infection and Vaccination

Infection with human papillomavirus (HPV) is the necessary cause of cervical cancer. Availability of vaccines against HPV makes it a highly preventable disease. HPV vaccines act through type-specific neutralizing antibodies produced by antigen-specific plasma cells known as long-lived plasma cells (LLPC). However, just as any other vaccine, success of HPV vaccine is attributed to the immunologic memory that it builds, which is largely attained through generation and maintenance of a class of B cells named memory B cells (Bmem). Both LLPCs and Bmems are important in inducing and maintaining immune memory and it is therefore necessary to understand their role after HPV vaccination to better predict outcomes. This review summarizes current knowledge of B-cell responses following HPV vaccination and natural infection, including molecular signatures associated with these responses.

Trend of HPV 16/18 Genotypes in Cervical Intraepithelial Neoplasia Grade 3: Data for 2007-2018

Aim

In the post-vaccination era, the starting age and time intervals of cervical screening could change (older age and longer screening intervals). This scenario may be achieved by significantly reducing human papillomavirus (HPV) 16/18 prevalence (genotypes included in the current vaccines). In this regard, assessing the trend over time of these HPV infections in high-grade cervical lesions can provide information on the objective. The present study aimed to evaluate the trend of HPV 16/18 over the years 2007–2018 in women with cervical intraepithelial neoplasia (CIN) grade 3.

Methods

This is a retrospective multi-institutional study including HPV genotyped and unvaccinated women under 30 with CIN3. The sample was divided into the following periods: 2007–2010, 2011–2014, 2015–2018. HPV genotypes were grouped in genotypes 16/18, genotypes 31/33/35/52/58/67 (genetically related to HPV16), genotypes 39/45/59/68/70 (genetically related to HPV18), genotypes 31/33/45/52/58 (high-risk types included in the nonavalent vaccine), possibly carcinogenic HPV (genotypes 26/30/53/67/70/73/82/85), low-risk HPV (genotypes 6/11/40/42/43/44/54/55/61). The trend between periods and HPV genotypes was measured using the Cochran–Armitage test for trend.

Results

The final analysis included 474 participants. HPV 16/18 prevalence decreased significantly over the years (77.8% vs 68.9% vs 66.0%, respectively, Ptrend=0.027). Possibly carcinogenic HPV (genotypes 26/30/53/67/70/73/82/85) showed a significant negative prevalence trend over time (4.9% vs 1.1% vs 1.3%, respectively, Ptrend=0.046). Finally, there was a significant positive trend over the years for high-risk HPV genotypes 31/33/45/52/58 in women under 25 (9.9% vs 17.0% vs 24.0%, respectively, Ptrend=0.048).

Conclusion

The prevalence of CIN3 lesions related to HPV 16/18 genotypes decreased over time from 2007 to 2018. These data highlight a herd effect of the HPV vaccine. However, fifteen years after HPV vaccine introduction, we are still a long way from herd immunity. The increase in high-risk types 31/33/45/52/58 will need to be reassessed when the nonavalent vaccine impact will be more reliable.

Differential Antibody Response against Conformational and Linear Epitopes of the L1 Proteins from Human Papillomavirus Types 16/18 Is Observed in Vaccinated Women or with Uterine Cervical Lesions

Antibodies against the Human Papillomavirus (HPV) L1 protein are associated with past infections and related to the evolution of the disease, whereas antibodies against L1 Virus-Like Particles (VLPs) are used to follow the neutralizing antibody response in vaccinated women. In this study, serum antibodies against conformational (VLPs) and linear epitopes of HPV16/18 L1 protein were assessed to distinguish HPV-vaccinated women from those naturally infected or those with uterine cervical lesions. The VLPs-16/18 were generated in baculovirus, and L1 proteins were obtained from denatured VLPs. Serum antibodies against VLPs and L1 proteins were evaluated by ELISA. The ELISA-VLPs and ELISA-L1 16/18 assays were validated with a vaccinated women group by ROC analysis and the regression analysis to distinguish the different populations of female patients. The anti-VLPs-16/18 and anti-L1-16/18 antibodies effectively detect vaccinated women (AUC = 1.0/0.79, and 0.94/0.84, respectively). The regression analysis showed that anti-VLPs-16/18 and anti-L1-16/18 antibodies were associated with the vaccinated group (OR = 2.11 × 10⁸/16.50 and 536.0/49.2, respectively). However, only the anti-L1-16 antibodies were associated with the high-grade lesions and cervical cancer (CIN3/CC) group (OR = 12.18). In conclusion, our results suggest that anti-VLPs-16/18 antibodies are effective and type-specific to detect HPV-vaccinated women, but anti-L1-16 antibodies better differentiate the CIN3/CC group. However, a larger population study is needed to validate these results.

Advances in Targeting HPV Infection as Potential Alternative Prophylactic Means

Infection by oncogenic human papillomavirus (HPV) is the primary cause of cervical cancer and other anogenital cancers. The majority of cervical cancer cases occur in low- and middle- income countries (LMIC). Concurrent infection with Human Immunodeficiency Virus (HIV) further increases the risk of HPV infection and exacerbates disease onset and progression. Highly effective prophylactic vaccines do exist to combat HPV infection with the most common oncogenic types, but the accessibility to these in LMIC is severely limited due to cost, difficulties in accessing the target population, cultural issues, and maintenance of a cold chain. Alternative preventive measures against HPV infection that are more accessible and affordable are therefore also needed to control cervical cancer risk. There are several efforts in identifying such alternative prophylactics which target key molecules involved in early HPV infection events. This review summarizes the current knowledge of the initial steps in HPV infection, from host cell-surface engagement to cellular trafficking of the viral genome before arrival in the nucleus. The key molecules that can be potentially targeted are highlighted, and a discussion on their applicability as alternative preventive means against HPV infection, with a focus on LMIC, is presented.

Antibody responses to prophylactic quadrivalent human papillomavirus vaccine at 48 months among HIV-infected girls and boys ages 9-14 in Kenya, Africa

OBJECTIVES

HIV infected children remain at increased risk of HPV associated malignancies as they initiate sexual activity. Though they mount a vigorous immune response to the quadrivalent human papillomavirus (QHPV-6, -11,-16, and -18; Gardasil®) vaccine, durability of the immune response is uncertain. We assessed antibody responses to HPV 6, -11, -16 and -18 for up to 48 months following administration of quadrivalent human papillomavirus vaccine in HIV-infected girls and boys ages 9-14 years in Kenya.

DESIGN

Of 178 girls and boys who had previously received three doses of the quadrivalent HPV vaccine, 176 enrolled into extended follow up for 4 years. HPV antibodies to -6, -11, -16 and -18 were measured at 24, 36 and 48 months after the first vaccine dose using the total immunoglobulin G immunoassay (IgG LIA). We evaluated the magnitude and trend in HPV vaccine response and the effect of plasma HIV-1 RNA on HPV vaccine response from month 24 to month 48 of follow up.

RESULTS

At re-enrollment, 24 months after initial vaccination, median age of participants was 14 years (range 11-17); 167 (95%) were receiving antiretroviral therapy and 110 (66%) had plasma HIV RNA < 40 copies/mL. The rate of HPV seropositivity at 48 months was 83% for HPV-6; 80% for HPV-11; 90% for HPV-16; and 77% for HPV-18. There was a plateau in mean log10 HPV-specific antibody titer between month 24 and 48. The mean log10 HPV-type specific antibody titer for children with undetectable HIV viral load (<40) at the time of vaccination consistently remained higher for the 48 months of follow up compared to children with detectable viral load.

CONCLUSION

Children with HIV infection may retain long term antibody response following HPV immunization. Further work to define whether HIV-infected children are protected from HPV acquisition with low levels of HPV antibodies is needed.

Comparison of a VLP-based and GST-L1-based multiplex immunoassay to detect vaccine-induced HPV-specific antibodies in first-void urine

Vaccine-induced human papillomavirus (HPV) antibodies originating from cervicovaginal secretions were recently shown to be detectable in first-void (FV) urine. This presents a novel opportunity for noninvasive sampling to monitor HPV antibody status in women participating in large epidemiological studies and HPV vaccine trials. With a view towards method optimization, this study compared the measurement of HPV antibodies in FV urine using a multiplex L1/L2 virus-like particles (VLP)-based ELISA (M4ELISA) with previously reported results using a glutathione S-transferase (GST)-L1-based immunoassay (GST-L1-MIA). We tested 53 paired FV urine and serum samples from 19- to 26-year-old healthy women, unvaccinated (n = 17) or vaccinated with either the bivalent or quadrivalent HPV-vaccine during adolescence (n = 36). HPV6/11/16/18 antibodies were measured using M4ELISA and compared with GST-L1-MIA results. Inter-assay and inter-specimen correlations were examined using the Spearman's rank test (rs). As expected, lower HPV antibody concentrations were found in FV urine than in serum. Vaccinated women had significantly higher HPV6/11/16/18 antibody levels in both FV urine and serum compared with those unvaccinated (M4ELISA; FV urine P = .0003; serum P ≤ .0001). HPV antibody levels in FV urine and serum showed a significant positive correlation (M4ELISA anti-HPV6/11/16/18, rs  = 0.85/0.86/0.91/0.79, P ≤ .001). Despite assay differences, there was moderate to good correlation between M4ELISA and GST-L1-MIA (FV urine anti-HPV6/11/16/18, rs  = 0.86/0.83/0.89/0.53, P ≤  .0001; serum anti-HPV6/11/16/18, rs  = 0.93/0.89/0.94/0.75, P ≤ .0001). FV urine HPV antibody detection is comparable with both assays, further supporting this noninvasive sampling method as a possible option for HPV vaccine assessment. Approaches to improve the sensitivity and larger studies are warranted to determine the feasibility of FV urine for vaccine-induced HPV antibody detection.

Long‐term persistence of immune response to the AS04‐adjuvanted HPV‐16/18 vaccine in Chinese girls aged 9‐17 years: Results from an 8‐9‐year follow‐up phase III open‐label study

Aim

In 9‐17‐year‐old Chinese girls, the AS04‐adjuvanted HPV‐16/18 vaccine (AS04‐HPV‐16/18) given as three‐dose schedule induced high antibody levels, which were noninferior 1 month after the third dose to those observed in 18‐25‐year‐old Chinese women in a large efficacy study. We assessed the persistence of antibodies 8‐9 years after vaccination in the same subjects.

Methods

This follow‐up phase III, open‐label study (NCT03355820) included subjects who had received three doses of AS04‐HPV‐16/18 in the initial trial (NCT00996125). Serum antibody concentrations were assessed by ELISA and compared to antibody persistence observed in 18‐25‐year‐old Chinese women 6 years after first vaccination in the efficacy study (NCT00779766).

Results

Out of the 227 enrolled subjects, 223 were included in the per‐protocol immunogenicity analysis. Mean interval from first AS04‐HPV‐16/18 dose to blood sampling was 101.4 months (8.5 years). For antibodies against HPV‐16 and ‐18, 8.5 years after first vaccine dose all subjects remained seropositive and antibody. Geometric mean concentrations (GMCs) were 1236.3 (95% confidence interval [CI]: 1121.8; 1362.4) and 535.6 (95% CI: 478.6; 599.4) ELISA Units/mL, respectively. These seropositivity rates and antibody GMCs were higher than those observed 6 years after first vaccination of 18‐25‐year‐old women.

Conclusion

Sustained anti‐HPV‐16 and ‐18 immune responses were observed 8‐9 years after AS04‐HPV‐16/18 vaccination of 9‐17 year‐old Chinese girls that were higher than the ones observed 6 years after first vaccination in Chinese adult women in whom AS04‐HPV‐16/18 efficacy against cervical intraepithelial neoplasia of grade ≥2 was demonstrated.

Chimeric Virus-Like Particles and Capsomeres Induce Similar CD8+ T Cell Responses but Differ in Capacity to Induce CD4+ T Cell Responses and Antibody Responses

Despite extensive research, the development of an effective malaria vaccine remains elusive. The induction of robust and sustained T cell and antibody response by vaccination is an urgent unmet need. Chimeric virus-like particles (VLPs) are a promising vaccine platform. VLPs are composed of multiple subunit capsomeres which can be rapidly produced in a cost-effective manner, but the ability of capsomeres to induce antigen-specific cellular immune responses has not been thoroughly investigated. Accordingly, we have compared chimeric VLPs and their sub-unit capsomeres for capacity to induce CD8⁺ and CD4⁺ T cell and antibody responses. We produced chimeric murine polyomavirus VLPs and capsomeres each incorporating defined CD8⁺ T cell, CD4⁺ T cell or B cell repeat epitopes derived from Plasmodium yoelii CSP. VLPs and capsomeres were evaluated using both homologous or heterologous DNA prime/boost immunization regimens for T cell and antibody immunogenicity. Chimeric VLP and capsomere vaccine platforms induced robust CD8⁺ T cell responses at similar levels which was enhanced by a heterologous DNA prime. The capsomere platform was, however, more efficient at inducing CD4⁺ T cell responses and less efficient at inducing antigen-specific antibody responses. Our data suggest that capsomeres, which have significant manufacturing advantages over VLPs, should be considered for diseases where a T cell response is the desired outcome.

Twenty years of research on HPV vaccines based on genetically modified lactic acid bacteria: an overview on the gut-vagina axis

Most cervical cancer (CxCa) are related to persistent infection with high-risk human papillomavirus (HR-HPV) in the cervical mucosa, suggesting that an induction of mucosal cell-mediated immunity against HR-HPV oncoproteins can be a promising strategy to fight HPV-associated CxCa. From this perspective, many pre-clinical and clinical trials have proved the potential of lactic acid bacteria (LAB) genetically modified to deliver recombinant antigens to induce mucosal, humoral and cellular immunity in the host. Altogether, the outcomes of these studies suggest that there are several key factors to consider that may offer guidance on improvement protein yield and improving immune response. Overall, these findings showed that oral LAB-based mucosal HPV vaccines expressing inducible surface-anchored antigens display a higher potential to induce particularly specific systemic and mucosal cytotoxic cellular immune responses. In this review, we describe all LAB-based HPV vaccine investigations by reviewing databases from international studies between 2000 and 2020. Our aim is to promote the therapeutic HPV vaccines knowledge and to complete the gaps in this field to empower scientists worldwide to make proper decisions regarding the best strategies for the development of therapeutic HPV vaccines.

Non-invasive Assessment of Vaccine-Induced HPV Antibodies via First-Void Urine

The potential of first-void (FV) urine as a non-invasive method to monitor human papillomavirus (HPV) vaccination has been reported, mainly focusing on urine as a sample to assess HPV DNA. Besides HPV DNA, vaccine-induced HPV antibodies originating from cervicovaginal secretions were recently shown to be detectable in FV urine as well. This presents a novel opportunity for non-invasive sampling to monitor HPV antibody status in women participating in large epidemiological studies and HPV vaccine trials. The simultaneous assessment of both HPV infection and immunogenicity on a non-invasive, readily obtained sample is particularly attractive.

Mouthwash-Based Highly Sensitive Pyro-Genotyping for Nine Sexually Transmitted Human Papilloma Virus Genotypes

Human papillomavirus (HPV) is a common sexually transmitted infection worldwide, which spreads via contact with infected genital, anal, and oral/pharyngeal areas (oral sex) owing to diverse manners of sexual intercourse. In this study, we devised an oral HPV detection method using mouthwash waste fluids that causes less psychological resistance to visiting the outpatient otolaryngology departments. We successfully detected only the specific unique reverse sequencing probe (using pyro-genotyping) and identified the nine genotypes of HPV targeted for vaccination by pyrosequencing the mouthwash waste fluids of non-head and neck cancer patient volunteers (n = 52). A relatively large number (11/52) of mouthwash waste fluids tested positive for HPV (21.2%; genotype 6, n = 1; 11, n = 1; 16, n = 1; and 18, n = 8). These results surpassed the sensitivity observed testing the same specimens using the conventional method (1/52, 1.9%). Our method (pyro-genotyping) was developed using nine HPV genotypes targeted for vaccination and the results were highly sensitive compared to those of the conventional method. This less expensive, high-throughput, and simple method can be used for detecting oral HPV infection with fewer socio-psychological barriers.

Human Papillomaviruses and Epstein-Barr Virus Interactions in Colorectal Cancer: A Brief Review

Human papillomaviruses (HPVs) and the Epstein-Barr virus (EBV) are the most common oncoviruses, contributing to approximately 10%-15% of all malignancies. Oncoproteins of high-risk HPVs (E5 and E6/E7), as well as EBV (LMP1, LMP2A and EBNA1), play a principal role in the onset and progression of several human carcinomas, including head and neck, cervical and colorectal. Oncoproteins of high-risk HPVs and EBV can cooperate to initiate and/or enhance epithelial-mesenchymal transition (EMT) events, which represents one of the hallmarks of cancer progression and metastasis. Although the role of these oncoviruses in several cancers is well established, their role in the pathogenesis of colorectal cancer is still nascent. This review presents an overview of the most recent advances related to the presence and role of high-risk HPVs and EBV in colorectal cancer, with an emphasis on their cooperation in colorectal carcinogenesis.

Infection and vaccine-induced HPV-specific antibodies in cervicovaginal secretions. A review of the literature

Background

Human papillomavirus (HPV) infects and propagates in the cervical mucosal epithelium. Hence, in addition to assessing systemic immunity, the accurate measurement of cervical immunity is important to evaluate local immune responses to HPV infection and vaccination. This review discusses studies that investigated the presence of infection and vaccine-induced HPV-specific antibodies in cervicovaginal secretions (CVS).

Methods

We searched the two main health sciences databases, PubMed and the ISI Web of Science, from the earliest dates available to March 2019. From the eligible publications, information was extracted regarding: (i) study design, (ii) the reported HPV-specific antibody concentrations in CVS (and the associated serum levels, when provided), (iii) the CVS collection method, and (iv) the immunoassays used.

Results

The systematic search and selection process yielded 44 articles. The evidence of HPV-specific antibodies in CVS after natural infection (26/44) and HPV vaccination (18/44) is discussed. Many studies indicate that HPV-specific antibody detection in CVS is variable but feasible with a variety of collection methods and immunoassays. Most CVS samples were collected by cervicovaginal washing or wicks, and antibody presence was mostly determined by VLP-based ELISAs. The moderate to strong correlation between vaccine-induced antibody levels in serum and in CVS indicates that HPV vaccines generate antibodies that transudate through the cervical mucosal epithelium.

Conclusion

Although HPV-specific antibodies have lower titres in CVS than in serum samples, studies have shown that their detection in CVS is feasible. Nevertheless, the high variability of published observations and the lack of a strictly uniform, well-validated method for the collection, isolation and quantification of antibodies indicates a need for specific methods to improve and standardize the detection of HPV-specific antibodies in CVS.

Efficacy, immunogenicity and safety of the AS04-HPV-16/18 vaccine in Chinese women aged 18-25 years: End-of-study results from a phase II/III, randomised, controlled trial

Background

Cervical cancer is a major public health concern in China. We report the end‐of‐study results of a phase II/III trial to assess the efficacy, immunogenicity, and safety of the AS04‐human papillomavirus (HPV)‐16/18 vaccine in Chinese women aged 18‐25 years followed for up to 72 months after first vaccination. Results of approximately 57 months following first vaccination have been previously reported.

Methods

Healthy 18‐25‐year‐old women (N = 6051) were randomized (1:1) to receive three doses of AS04‐HPV‐16/18 vaccine or Al(OH)₃ (control) at Months 0‐1‐6. Vaccine efficacy against HPV‐16/18 infection and cervical intraepithelial neoplasia (CIN), cross‐protective vaccine efficacy against infections and lesions associated with nonvaccine oncogenic HPV types, immunogenicity, and safety were assessed. Efficacy was assessed in the according‐to‐protocol efficacy (ATP‐E) cohort (vaccine N = 2888; control N = 2892), total vaccinated cohort for efficacy (TVC‐E; vaccine N = 2987; control N = 2985) and TVC‐naïve (vaccine N = 1660; control N = 1587).

Results

In initially HPV‐16/18 seronegative/DNA‐negative women, vaccine efficacy against HPV‐16/18‐associated CIN grade 2 or worse was 87.3% (95% CI: 5.5, 99.7) in the ATP‐E, 88.7% (95% CI: 18.5, 99.7) in the TVC‐E, and 100% (95% CI: 17.9, 100) in the TVC‐naïve. Cross‐protective efficacy against incident infection with HPV‐31, HPV‐33 and HPV‐45 was 59.6% (95% CI: 39.4, 73.5), 42.7% (95% CI: 15.6, 61.6), and 54.8% (95% CI: 19.3, 75.6), respectively (ATP‐E). At Month 72, >95% of initially seronegative women who received HPV vaccine in the ATP cohort for immunogenicity (N = 664) remained seropositive for anti‐HPV‐16/18 antibodies; anti‐HPV‐16 and anti‐HPV‐18 geometric mean titers were 678.1 EU/mL (95% CI: 552.9, 831.5) and 343.7 EU/mL (95% CI: 291.9, 404.8), respectively. Serious adverse events were infrequent (1.9% vaccine group [N = 3026]; 2.7% control group [N = 3025]). Three and zero women died in the control group and the vaccine group respectively. New onset autoimmune disease was reported in two women in the vaccine group and two in the control group.

Conclusions

This is the first large‐scale randomized clinical trial of HPV vaccination in China. High and sustained vaccine efficacy against HPV‐16/18‐associated infection and cervical lesions was demonstrated up to Month 72. The vaccine had an acceptable safety profile. Combined with screening, prophylactic HPV vaccination could potentially reduce the high burden of HPV infection and cervical cancer in China.

Trial registration

NCT00779766.

Immunogenicity noninferiority study of 2 doses and 3 doses of an Escherichia coli-produced HPV bivalent vaccine in girls vs. 3 doses in young women

A new HPV-16/18 bivalent vaccine expressed by the Escherichia coli has been proven to be efficacious in adult women. A randomized, immunogenicity noninferiority study of this candidate vaccine was conducted in December 2015 in China. Girls aged 9–14 years were randomized to receive 2 doses at months 0 and 6 (n=301) or 3 doses at months 0, 1 and 6 (n=304). Girls aged 15–17 years (n=149) and women aged 18–26 years (n=225) received 3 doses. The objectives included noninferiority analysis of the IgG geometric mean concentration (GMC) ratio (95% CI, lower bound>0.5) to HPV-16 and HPV-18 at month 7 in girls compared with women. In the per-protocol set, the GMC ratio of IgG was noninferior for girls aged 9–17 years receiving 3 doses compared with women (1.76 (95% CI, 1.56, 1.99) for HPV-16 and 1.93 (95% CI, 1.69, 2.21) for HPV-18) and noninferior for girls aged 9–14 years receiving 2 doses compared with women (1.45 (95% CI, 1.25, 1.62) for HPV-16 and 1.17 (95% CI, 1.02, 1.33) for HPV-18). Noninferiority was also demonstrated for neutralizing antibodies. The immunogenicity of the HPV vaccine in girls receiving 3 or 2 doses was noninferior compared with that in young adult women.

Chimeric Murine Polyomavirus Virus-Like Particles Induce Plasmodium Antigen-Specific CD8+ T Cell and Antibody Responses

An effective vaccine against the Plasmodium parasite is likely to require the induction of robust antibody and T cell responses. Chimeric virus-like particles are an effective vaccine platform for induction of antibody responses, but their capacity to induce robust cellular responses and cell-mediated protection against pathogen challenge has not been established. To evaluate this, we produced chimeric constructs using the murine polyomavirus structural protein with surface-exposed CD8+ or CD4+ T cell or B cell repeat epitopes derived from the Plasmodium yoelii circumsporozoite protein, and assessed immunogenicity and protective capacity in a murine model. Robust CD8+ T cell responses were induced by immunization with the chimeric CD8+ T cell epitope virus-like particles, however CD4+ T cell responses were very low. The B cell chimeric construct induced robust antibody responses but there was no apparent synergy when T cell and B cell constructs were administered as a pool. A heterologous prime/boost regimen using plasmid DNA priming followed by a VLP boost was more effective than homologous VLP immunization for cellular immunity and protection. These data show that chimeric murine polyomavirus virus-like particles are a good platform for induction of CD8+ T cell responses as well as antibody responses.

Evidence on the prevalence, incidence, mortality and trends of human papilloma virus-associated cancers in sub-Saharan Africa: systematic scoping review

BACKGROUND

Human papilloma virus (HPV) associated cervical cancer remains a global concern particular, in Sub-Saharan Africa (SSA) where the impact is felt most. Evidence show that many other cancers such as vaginal, anal, oropharyngeal, penile are because of persistent infection with HPV especially, high-risk types.

AIM

We mapped evidence on the incidence, prevalence, mortality, and the trends of human papillomavirus-related cancers in SSA.

METHODS

A comprehensive literature search was conducted from several databases including PubMed, Google scholar, Science Direct, and CINAHL and MEDLINE via EBSCOhost as well as World Health Organization website for grey literature. Studies reporting HPV-related cancers in SSA outcomes including prevalence, incidence, mortality, and trends were included in this study. The risk of bias of the included studies were assessed using the mixed methods appraisal tool version 2011. We employed PRISMA (preferred reporting items for systematic reviews and meta-analyses) to report the search results. Thematic analysis used to reveal the emerging themes from the included studies.

RESULTS

Seventy-four (74) studies were retrieved at full article screening, eight of them (six reviews, and two quantitative study) were eligible for data extraction. The degree of agreement between the two independent reviewers following full article screening, was 86.49% agreement versus 64.57% likely by chance which constituted moderate to significant agreement (Kappa statistic = 0.62, p-value< 0.05). Of the eight included studies, four (50%) studies generalized about SSA with no country of interest; two (25%) studies were conducted in Nigeria; one (12.5%) reported about Uganda, Zambia, Guinea, Malawi Tanzania, Mali, Mozambique, Zimbabwe; and one (12.5%) reported about Ethiopia, Senegal, Zimbabwe and Uganda. These eight included studies reported evidence on more than one outcome of interest. Four studies reported about the prevalence of HPV-related cancers, seven studies reported about the incidence, four studies reported about mortality, and four studies reported about the trends of HPV-related cancers.

CONCLUSION

This study observation highlighted a gap of knowledge regarding the epidemiological data on the recent HPV prevalence in SSA, which will have a potential impact in determining the distribution of HPV on different body sites (cervix, penis, vagina, vulva, anus and oropharynx). Ongoing research projects are recommended in SSA to enhance the value of HPV, and HPV-associated cancers epidemiological data to inform strategies or/and policies on prevention, diagnosis, and treatment of HPV-related conditions.

Natural history of human papillomavirus and vaccinations in men: A literature review

BACKGROUND AND AIMS

Infection with high-risk (HR) genotypes of the human papillomavirus (HPV) is necessary for and causative of almost all cervical cancers and their precursor condition, cervical intraepithelial neoplasia. These conditions have been sharply reduced by cervical cytology screening, and a further decrease is expected because of the recent introduction of prophylactic HPV vaccinations. While significant attention has been given to gynecologic HPV disease, men can be affected by HPV-related cancers of the anus, penis, and oropharynx. This literature review aims to address disparities in HPV-related disease in men, and certain HR male subpopulations, compared with women.

DISCUSSION

Overall, immunocompetent men are far less likely than women to develop anogenital HPV-related cancers, despite harboring HR HPV infections at anogenital sites. On the other hand, men who have sex with men and men living with human immunodeficiency virus infection are at considerably higher risk of HPV-related disease. Historic rates of prophylactic HPV vaccination in males have trailed those of females due to numerous multilevel factors, although, in recent years, this sex gap in vaccination coverage has been closing. In the absence of routine HPV screening in males, therapeutic vaccinations have emerged as a potential treatment modality for preinvasive neoplasia and are in various phases of clinical testing.

CONCLUSION

Successful reductions in HPV disease morbidity at the population level must acknowledge and target HPV infections in men.

Immunization of mice by the co-administration of codon-optimized HPV16 E7 and lL12 genes against HPV16-associated cervical cancer

BACKGROUND

Various promising procedures have been used to improve the potency of DNA vaccines for the treatment of human papillomavirus type 16 (HPV16) infections. Interleukin-12 (IL12) is a powerful adjuvant that can contribute to T cell-mediated protection against many pathogens, specifically viruses. Considering the important role of T cell-mediated immunity in tumor clearance, the induction of these responses can help control the progression of tumors in animal models. We have demonstrated that the co-administration of codon-optimized E7 (uE7) gene of HPV16 with interleukin-12 is effective in the development of antitumor responses.

OBJECTIVES

The present study examined the co-administration of codon-optimized HPV16 E7 gene with murine interleukin-12 gene (mIL-12) as a vaccine adjuvant in tumor mice model.

MATERIALS AND METHODS

C57BL/6 mice were studied for tumor progression after injection of recombinant DNA vaccines. Lactate dehydrogenase (LDH) and IFN-γ were measured to evaluate the activity of cytotoxic T lymphocytes (CTLs). Measurements of tumor volume and MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay were used for assessment of therapeutic antitumor effects of the vaccines.

RESULTS

Results showed that DNA vaccines, specifically codon-optimized E7/murine interleukin-12 (mIL-12), elicited significant differences in levels of IFN-γ and cytotoxic T lymphocyte (CTLs) responses compared to control groups. Furthermore, higher antitumor response and lower tumor size in the vaccine group was significantly evident compared to control group.

CONCLUSION

The co-administration of codon-optimized HPV16 E7 gene with IL12 significantly enhances the DNA vaccine potency against HPV16-associated cervical cancer.

Non-Vaccine-Type Human Papillomavirus Prevalence After Vaccine Introduction: No Evidence for Type Replacement but Evidence for Cross-Protection

BACKGROUND

We examined non-vaccine-type human papillomavirus (HPV) prevalence in a community before and during the first 8 years after vaccine introduction, to assess for (1) type replacement with any non-vaccine-type HPV and (2) cross-protection with non-vaccine types genetically related to vaccine-type HPV.

METHODS

Sexually experienced 13- to- 26-year-old women were recruited for 3 cross-sectional studies from 2006 to 2014 (N = 1180). Outcome variables were as follows: (1) prevalence of at least 1 of 32 anogenital non-vaccine-type HPVs and (2) prevalence of at least 1 HPV type genetically related to HPV-16 and HPV-18. We determined changes in proportions of non-vaccine-type HPV prevalence across the study waves using logistic regression with propensity score inverse probability weighting.

RESULTS

Vaccine initiation rates increased from 0% to 71.3%. Logistic regression demonstrated that from 2006 to 2014, there was no increase in non-vaccine-type HPV among vaccinated women (adjusted odds ratio [AOR], 1.02; 95% confidence interval [CI], 0.73-1.42), but an increase among unvaccinated women (AOR, 1.88; 95% CI, 1.16-3.04). Conversely, there was a decrease in types genetically related to HPV-16 among vaccinated (AOR, 0.57; 95% CI, 0.38-0.88) but not unvaccinated women (AOR, 1.33; 95% CI, 0.81-2.17).

CONCLUSIONS

We did not find evidence of type replacement, but did find evidence of cross-protection against types genetically related to HPV-16. These findings have implications for cost-effectiveness analyses, which may impact vaccine-related policies, and provide information to assess the differential risk for cervical cancer in unvaccinated and vaccinated women, which may influence clinical screening recommendations. The findings also have implications for public health programs, such as health messaging for adolescents, parents, and clinicians about HPV vaccination.

Evidence for cross-protection but not type-replacement over the 11 years after human papillomavirus vaccine introduction

Examination of cross-protection and type replacement after human papillomavirus (HPV) vaccine introduction is essential to guide vaccination recommendations and policies. The aims of this study were to examine trends in non-vaccine-type HPV: 1) genetically related to vaccine types (to assess for cross-protection) and 2) genetically unrelated to vaccine types (to assess for type replacement), among young women 13-26 years of age during the 11 years after HPV vaccine introduction. Participants were recruited from a hospital-based teen health center and a community health department for four cross-sectional surveillance studies between 2006 and 2017. Participants completed a survey that assessed sociodemographic characteristics and behaviors, and cervicovaginal swabs were collected and tested for 36 HPV genotypes. We determined changes in proportions of non-vaccine-type HPV prevalence and conducted logistic regression to determine the odds of infection across the surveillance studies, propensity-score adjusted to control for selection bias. Analyses were stratified by vaccination status. Among vaccinated women who received only the 4-valent vaccine (n = 1,540), the adjusted prevalence of HPV types genetically related to HPV16 decreased significantly by 45.8% (adjusted odds ratio [AOR] = 0.48, 95% confidence interval [CI] = 0.31-0.74) from 2006-2017, demonstrating evidence of cross-protection. The adjusted prevalence of HPV types genetically related to HPV18 did not change significantly (14.2% decrease, AOR = 0.83, 95% CI = 0.56-1.21). The adjusted prevalence of HPV types genetically unrelated to vaccine types did not change significantly (4.2% increase, AOR = 1.09, CI = 0.80-1.48), demonstrating no evidence of type replacement. Further studies are needed to monitor for cross-protection and possible type replacement after introduction of the 9-valent HPV vaccine.

Attitudes towards and knowledge about Human Papillomavirus (HPV) and the HPV vaccination in parents of teenage boys in the UK

The incidence of cancers attributable to Human Papillomavirus (HPV) that affect males is on the rise. Currently in the UK teenage boys are not vaccinated against HPV while teenage girls are. The rationale for not vaccinating boys is that vaccinating girls should provide herd immunity to boys, however this does not protect men who have sex with men or men who have sex with unvaccinated women. The issue of whether to vaccinate boys or not is a controversial one with considerable lobbying taking place to change the existing policy. On one side of the debate are financial considerations while on the other side health equality is important. One avenue that has not been presented is the parental perspective. The current study uses a self-report questionnaire to explore what parents of teenage boys know about HPV and the vaccine and whether they want the vaccine for their sons. Only half of the parents had heard of HPV prior to completing the survey. Of those who had heard of HPV, knowledge about the health sequelae of HPV for men was poor relative to their knowledge about its impact on female health. Parents who would be willing to vaccinate their sons had higher levels of knowledge about HPV than those parents who would be unwilling or unsure. Irrespective of whether they had previously heard of HPV or not, once provided with a brief description of HPV, the majority of parents thought that boys should be offered the vaccination. There is a pressing need for public education about the potential impact of HPV on male health in order to facilitate uptake of the vaccine in the event of the vaccination programme being extended to men or to facilitate informed decision making about seeking the vaccine privately in the event that it isn't.

Tumour virus vaccines: hepatitis B virus and human papillomavirus

Two of the most important human oncogenic viruses are hepatitis B virus (HBV) and human papillomavirus (HPV). HBV infection has been preventable by vaccination since 1982; vaccination of neonates and infants is highly effective, resulting already in decreased rates of new infections, chronic liver disease and hepato-cellular carcinoma. Nonetheless, HBV remains a global public health problem with high rates of vertical transmission from mother to child in some regions. Prophylactic HPV vaccines composed of virus-like particles (VLPs) of the L1 capsid protein have been licensed since 2006/2007. These target infection by the oncogenic HPVs 16 and 18 (the cause of 70% of cervical cancers); a new vaccine licensed in 2014/2015 additionally targets HPVs 31, 33, 45, 52, 58. HPV vaccines are now included in the national immunization programmes in many countries, with young adolescent peri-pubertal girls the usual cohort for immunization. Population effectiveness in women is now being demonstrated in countries with high vaccine coverage with significant reductions in high-grade cervical intra-epithelial neoplasia (a surrogate for cervical cancer), genital warts and vaccine HPV type genoprevalence. Herd effects in young heterosexual men and older women are evident. Cancers caused by HBV and HPV should, in theory, be amenable to immunotherapies and various therapeutic vaccines for HPV in particular are in development and/or in clinical trial.This article is part of the themed issue 'Human oncogenic viruses'.

Quadrivalent human papillomavirus vaccine and autoimmune adverse events: a case-control assessment of the vaccine adverse event reporting system (VAERS) database

Gardasil is a quadrivalent human papillomavirus (HPV4) vaccine that was approved for use by the US Food and Drug Administration in June 2006. HPV4 vaccine is routinely recommended for administration to women in the USA who are 11-12 years old by the Advisory Committee on Immunization Practices. Previous studies suggest HPV4 vaccine administration was associated with autoimmune diseases. As a consequence, an epidemiological assessment of the vaccine adverse event reporting system database was undertaken for adverse event reports associated with vaccines administered from 2006 to 2014 to 6-39 year-old recipients with a listed US residence and a specified female gender. Cases with the serious autoimmune adverse event (SAAE) outcomes of gastroenteritis (odds ratio (OR) 4.627, 95 % confidence interval (CI) 1.892-12.389), rheumatoid arthritis (OR 5.629, 95 % CI 2.809-12.039), thrombocytopenia (OR 2.178, 95 % CI 1.222-3.885), systemic lupus erythematosus (OR 7.626, 95 % CI 3.385-19.366), vasculitis (OR 3.420, 95 % CI 1.211-10.408), alopecia (OR 8.894, 95 % CI 6.255-12.914), CNS demyelinating conditions (OR 1.585, 95 % CI 1.129-2.213), ovarian damage (OR 14.961, 95 % CI 6.728-39.199), or irritable bowel syndrome (OR 10.021, 95 % CI 3.725-33.749) were significantly more likely than controls to have received HPV4 vaccine (median onset of initial symptoms ranged from 3 to 37 days post-HPV4 vaccination). Cases with the outcome of Guillain-Barre syndrome (OR 0.839, 95 % CI 0.601-1.145) were no more likely than controls to have received HPV4 vaccine. In addition, cases with the known HPV4-related outcome of syncope were significantly more likely than controls to have received HPV4 vaccine (OR 5.342, 95 % CI 4.942-5.777). Cases with the general health outcomes of infection (OR 0.765, 95 % CI 0.428-1.312), conjunctivitis (OR 1.010, 95 % CI 0.480-2.016), diarrhea (OR 0.927, 95 % CI 0.809-1.059), or pneumonia (OR 0.785, 95 % CI 0.481-1.246) were no more likely than controls to have received HPV4 vaccine. Confirmatory epidemiological studies in other databases should be undertaken and long-term clinical consequences of HPV-linked SAAEs should be examined.

PREVALENCE OF HUMAN PAPILLOMAVIRUS GENOTYPES IN LOW AND HIGH GRADE SQUAMOUS INTRAEPITHELIAL LESIONS AT CERVICAL TISSUE

HPV infection is known to cause cervical cancer. This study aimed to identify the variant of HPV genotypes of cervical precancerous lesions from low grade squamous intraepithelial lesion  (LSIL) and high grade squamous intraepithelial lesion (HSIL). This was an explorative study using formalin fix paraffin embedded (FFPE) from cervical precancerous lesions at Dr. Soetomo Hospital, Surabaya. DNA was extracted from FFPE and hybridized for HPV genotyping using Ampliquality HPV Type Express kit (AB ANALITICA) by reverse line blot techniques. The results showed that there were variants of HPV genotype in LSIL. The variants were HPV16 (8/15), HPV18 (3/15), HPV52 (1/15), HPV6+31 (1/15), HPV6+18 (1/15), and HPV72+68 (1/15), and in HSIL which were HPV16 (4/10), HPV18 (2/10), HPV59 (1/10), HPV6+45 (1/10), HPV61+26 (1/10), and HPV16+31 (1/10). The characteristics of infection in LSIL were single infection of high-risk (hr) HPV and multiple infection of  low-risk (lr)+hr HPV, and in HSIL were single infection of HPVhr, multiple infection of HPVhr+hr and HPVlr+hr. In conclusion, HPV prevalence in cervical precancerous lesions is single infection by HPV16 (48%), HPV18 (20%), HPV52 (4%), HPV59 (4%), and multiple infection by HPV6+31, HPV6+18, HPV6+45, HPV16+31, HPV61+26, HPV72+68 is 4%.

Vaccination and allergy: EAACI position paper, practical aspects

Immunization is highly effective in preventing infectious diseases and therefore an indispensable public health measure. Allergic patients deserve access to the same publicly recommended immunizations as non-allergic patients unless risks associated with vaccination outweigh the gains. Whereas the number of reported possible allergic reactions to vaccines is high, confirmed vaccine-triggered allergic reactions are rare. Anaphylaxis following vaccination is rare, affecting <1/100 000, but can occur in any patient. Some patient groups, notably those with a previous allergic reaction to a vaccine or its components, are at heightened risk of allergic reaction and require special precautions. Allergic reactions, however, may occur in patients without known risk factors and cannot be predicted by currently available tools. Unwarranted fear and uncertainty can result in incomplete vaccination coverage for children and adults with or without allergy. In addition to concerns about an allergic reaction to the vaccine itself, there is fear that routine childhood immunization may promote the development of allergic sensitization and disease. Thus, although there is no evidence that routine childhood immunization increases the risk of allergy development, such risks need to be discussed.

Cervical cancer screening in the era of HPV vaccination: A review of shifting paradigms in cytopathology

Significant changes in cervical cancer screening practice, guidelines, and prevention of cervical cancer have taken place in recent years including the raising of initial cervical cancer screening age, changes in frequency of cytology screening, and the adoption of high risk HPV and cytology co-testing for some patients; the introduction of the bivalent, quadrivalent, and 9-valent HPV vaccines; and the recent approval of high risk HPV testing as primary screening with the use of cytology as triage in positive cases. This review discusses the significance of primary HPV screening, the impact of HPV vaccination in the prevalence of cervical cancer and its precursors, the interplay between high risk HPV testing and vaccination, and the implications for clinical and cytological management. Future strategies for cervical screening in the post-vaccination era are also discussed.

Immunogenicity and safety of quadrivalent human papillomavirus types 6/11/16/18 recombinant vaccine in chronic kidney disease stage IV, V and VD

Background

Up to >80% of sexually active adults will become infected with human papillomavirus (HPV) during their lifetime. Persistent HPV infection can result in cervical, vulvovaginal, penile and anogenital cancer. Clinical studies have shown the efficacy of three doses of quadrivalent HPV-6/11/16/18 L1 virus-like particle (VLP) vaccination, at Day 0, Month 2 and Month 6, to lower the occurrence of HPV infection and its complications. However, immunogenicity and safety of the HPV vaccine have not been proven in the chronic kidney disease (CKD) population.

Methods

Sixty CKD stage IV, V and VD patients were enrolled for quadrivalent HPV-6/11/16/18 vaccination. A dose of vaccine was given at Day 0, Month 2 and Month 6. Each dose contained 20 μg HPV-6 L1 VLP, 40 μg HPV-11 L1 VLP, 40 μg HPV-16 L1 VLP and 20 μg HPV-18 L1 VLP, along with 225 μg of amorphous aluminum hydroxyphosphate sulfate adjuvant. HPV type-specific antibody response to neutralizing epitopes on HPV-6/11/16/18 was performed by multiplexed, competitive Luminex® immunoassays (cLIA) at Day 0 and Month 7.

Results

At Day 0, anti-HPV seropositivity was 0-6.6% depending on HPV genotype. Patients who received three doses of vaccine had 98.2, 100, 100 and 98.2% seropositivity for genotypes 6/11/16/18, respectively. The average cLIA at Month 7 for genotypes 6/11/16/18 were 928.4 ± 231.1, 1136.1 ± 264.6, 6951.0 ± 1872.3 and 2196.3 ± 761.2 milliMerck units (mMu)/mL, respectively. No serious vaccine-related adverse events were observed.

Conclusions

Quadrivalent HPV vaccine has been well tolerated, is safe and provides excellent immunogenicity in late-stage CKD.

Efficacy, immunogenicity, and safety of the HPV-16/18 AS04-adjuvanted vaccine in Chinese women aged 18-25 years: event-triggered analysis of a randomized controlled trial

We previously reported the results of a phase II/III, double‐blind, randomized controlled study in Chinese women (NCT00779766) showing a 94.2% (95% confidence interval: 62.7–99.9) HPV‐16/18 AS04‐adjuvanted vaccine efficacy (VE) against cervical intraepithelial neoplasia grade 1 or higher (CIN1+) and/or 6‐month (M) persistent infection (PI) with a mean follow‐up of <2 years, and immunogenicity until 7 months post‐dose 1. Here, we report efficacy and safety results from an event‐triggered analysis with ~3 years longer follow‐up, and immunogenicity until M24. Healthy 18–25‐year‐old women (N = 6051) were randomized (1:1) to receive three doses of HPV‐16/18 vaccine or Al(OH)₃ (control) at M0, 1, 6. VE against HPV‐16/18‐associated CIN2+, and cross‐protective VE against infections with nonvaccine oncogenic HPV types, immunogenicity, and safety were assessed. In the according‐to‐protocol efficacy cohort, in initially seronegative/DNA‐negative women (vaccine group: N = 2524; control group: N = 2535), VE against HPV‐16/18‐associated CIN2+ was 87.3% (5.3–99.7); VE against incident infection or against 6‐month persistent infection associated with HPV‐31/33/45 was 50.1% (34.3–62.3) or 52.6% (24.5–70.9), respectively. At least, 99.6% of HPV‐16/18‐vaccines remained seropositive for anti‐HPV‐16/18 antibodies; anti‐HPV‐16 and ‐18 geometric mean titers were 1271.1 EU/mL (1135.8–1422.6) and 710.0 EU/ml (628.6–801.9), respectively. Serious adverse events were infrequent (1.7% vaccine group [N = 3026]; 2.5% control group [N = 3026]). Of the 1595 reported pregnancies, nine had congenital anomalies (five live infants, three elective terminations, one stillbirth) that were unlikely vaccination‐related (blinded data). VE against HPV‐16/18‐associated CIN2+ was demonstrated and evidence of cross‐protective VE against oncogenic HPV types was shown. The vaccine was immunogenic and had an acceptable safety profile.

Estimating long-term clinical effectiveness and cost-effectiveness of HPV 16/18 vaccine in China

BACKGROUND

Human papillomavirus (HPV) 16 and 18 are the two most common HPV oncogenic types that can be prevented by vaccination. This study aimed at assessing the cost-effectiveness of 3 doses of the bivalent HPV vaccine in rural and urban settings in China.

METHODS

A Markov model was adapted to reflect the lifetime of a modelled 100,000 12-year-old girls cohort in rural and urban settings in China. Input parameters were obtained from published literature, official reports and a two-round expert review panel. Clinical and economic outcomes of vaccination at age 12 with screening was compared to screening only. In the base case analysis, a 3 % discount rate, the vaccine cost of 247 CNY (US$ 39, PAHO vaccine cost in 2013), two rounds of screening in a life time and 70 % coverage for both screening and vaccination were used. One-way, two-way and probabilistic sensitivity analyses were performed. We used different thresholds of cost-effectiveness to reflect the diversity of economic development in China.

RESULTS

Vaccination in addition to screening could prevent 60 % more cervical cancer cases and deaths than screening only. The incremental cost effectiveness ratio varied largely when changing cost of vaccination and discount in one way analysis. Vaccination was very cost-effective when the vaccine cost ranged 87-630 CNY (US$ 13.8-100) in rural and 87-750 CNY (US$ 13.8-119) in urban; and remained cost-effective when the vaccine cost ranged 630-1,700 CNY (US$ 100-270) in rural and 750-1,900 CNY (US$ 119-302) in urban in two way analysis. Probabilistic sensitivity analyses showed that model results were robust.

CONCLUSIONS

In both rural and urban, the vaccination cost and discounting are important factors determining the cost-effectiveness of HPV vaccination; policy makers in China should take these into account when making a decision on the introduction of HPV vaccine. In areas with a high burden of cervical cancer and limited screening activities, HPV vaccination should be prioritized. However, the vaccine cost needs to be reduced in order to make it very cost-effective and affordable as well, in particular in poverty areas with high disease burden.

The Effect of Cryotherapy on Human Papillomavirus Clearance Among HIV-Positive Women in Lusaka, Zambia

OBJECTIVE

We sought to investigate the progression of human papillomaviruses (HPV) infection in HIV-positive women after cryotherapy.

METHODS

We examined changes in detection of high-risk HPV (hrHPV) cervical infections among HIV-infected women over a 12-week period after cryotherapy using stored specimens from a cohort study conducted between June 2009 and March 2011 in Lusaka, Zambia. Samples from visits at baseline and weeks 4, 8, and 12 were tested using the Roche Linear Array assay.

RESULTS

A total of 89 women were included in the analysis. The median age was 32 years (interquartile range [IQR], 28-36 years). The median CD4+ cell count was 350 cells/μL (IQR, 214-470 cells/μL), and 66% of women were receiving antiretroviral therapy. At baseline, the prevalence of hrHPV was 91% (95% confidence interval [CI], 83%-95%). HPV45 was the most common HPV type, present in (30%) women, followed by HPV16 (27%), HPV18 (27%), HPV51 (20%), and HPV58 (22%). Among women with valid results both at baseline and 12 weeks, 25% (17/67) cleared their initial hrHPV infection within 12 weeks of treatment, although 65% (11/17) had new hrHPV types detected.

CONCLUSIONS

Cryotherapy led to clearance of 25% of hrHPV infections within 12 weeks of treatment. However, hrHPV infection remained persistent in most women, and new hrHPV types were detected often, explaining the high rate of persistence and recurrence of cervical disease in this population. Continued efforts to scale up HPV vaccination and cervical screening should remain a priority in high HIV burden settings such as Zambia.

Comparison of HPV prevalence between HPV-vaccinated and non-vaccinated young adult women (20-26 years)

There is some concern about the effectiveness of the HPV vaccine among young adult women due to the risk of prior HPV infection. This study used National Health and Nutrition Examination Survey (NHANES) 2007-2012 data to evaluate the effectiveness of HPV vaccination among women 20-26 years of age who were vaccinated after 12 years of age. This cross-sectional study examined 878 young adult women (20-26 years) with complete information on HPV prevalence and HPV vaccination status from NHANES 2007-2012. Vaginal swab specimens were analyzed for HPV DNA by L1 consensus polymerase chain reaction followed by type-specific hybridization. Multivariate logistic regression models controlling for sociodemographic characteristics and sexual behaviors were used to compare type-specific HPV prevalence between vaccinated and unvaccinated women. A total of 21.4% of young adult women surveyed through NHANES between 2007 and 2012 received the HPV vaccine. Vaccinated women had a lower prevalence of vaccine types than unvaccinated women (7.4% vs 17.1%, prevalence ratio 0.43, 95% CI 0.21-0.88). The prevalence of high-risk nonvaccine types was higher among vaccinated women than unvaccinated women (52.1% vs 40.4%, prevalence ratio 1.29, 95% CI 1.06-1.57), but this difference was attenuated after adjusting for sexual behavior variables (adjusted prevalence ratio 1.19, 95% CI 0.99-1.43). HPV vaccination was effective against all 4 vaccine types in young women vaccinated after age 12. However, vaccinated women had a higher prevalence of high-risk nonvaccine types, suggesting that they may benefit from newer vaccines covering additional types.

HPV vaccines: how many doses are needed for protection?

HPV virus-like particle vaccines are highly immunogenic, well tolerated and are in the national immunization programs in more than 62 countries. Genital HPV is a sexually transmitted infection with first infection occurring just after the onset of sexual activity. The routine cohort for immunization in almost all countries are adolescent girls 9–15 years of age with or without catch-up for older adolescents and young women. In countries with vaccine coverage exceeding 50%, reductions in vaccine type HPV geno-prevalence and disease are being shown. The mechanism of protection is assumed to be via neutralizing antibody. Antibody concentration in adolescents less than 14 years of age after two doses of vaccine at 0 and 6 months are noninferior to women after three doses and in whom efficacy was demonstrated in randomized control trials. The original three-dose schedules have already been reduced in many countries, for those 14 years of age and under, to two doses at least 6 months apart for the licensed vaccines Cervarix® and GARDASIL®. There is preliminary evidence that one dose of vaccine is as effective as two or three doses at preventing persistent HPV infection in the cervix in young women and a one-dose schedule may be possible if supported by evidence from randomized controlled trials.

The Human Papillomavirus Vaccine: Current Perspective and Future Role in Prevention and Treatment of Anal Intraepithelial Neoplasia and Anal Cancer

The incidences of human papillomavirus (HPV)-related anal cancer and its precursor lesion, anal intraepithelial neoplasia, are rising in the U.S. and globally. Five-year survival rates with current modalities of treatment for anal cancer are generally favorable for localized and regional disease. For metastatic disease, the relative survival rate is poor. Major contributing factors for the increase in anal cancer incidence include increasing receptive anal intercourse (hetero- and homosexual), increasing HPV infections, and longer life expectancy of treated people who are seropositive for human immunodeficiency virus. Because treatment outcomes with systemic therapy in patients with advanced disease are so poor, prevention may be the best approach for reducing disease burden. The association of a major causative agent with anal cancer provides an excellent opportunity for prevention and treatment. The advent of the HPV vaccine for anal cancer prevention and treatment is a significant milestone and has the potential to greatly impact these cancers. The data regarding potential use of the HPV vaccine in anal cancer prevention and treatment are reviewed.

IMPLICATIONS FOR PRACTICE

The incidences of human papillomavirus (HPV)-related anal cancer and its precursor lesion, anal intraepithelial neoplasia, are on the rise in the U.S. and globally. Based on recent studies, the HPV vaccine is approved for prevention of the infection and development of HPV-related anal cancer. In addition, several small studies have shown that the vaccine may be useful as adjuvant therapy for anal cancer. There is a need for public health strategies aimed at education of both patients and practitioners to improve the use of the vaccine for prevention of HPV-related anal cancer. The development of a therapeutic vaccine is a work in progress.

Different applications of virus-like particles in biology and medicine: Vaccination and delivery systems

Virus-like particles (VLPs) mimic the whole construct of virus particles devoid of viral genome as used in subunit vaccine design. VLPs can elicit efficient protective immunity as direct immunogens compared to soluble antigens co-administered with adjuvants in several booster injections. Up to now, several prokaryotic and eukaryotic systems such as insect, yeast, plant, and E. coli were used to express recombinant proteins, especially for VLP production. Recent studies are also generating VLPs in plants using different transient expression vectors for edible vaccines. VLPs and viral particles have been applied for different functions such as gene therapy, vaccination, nanotechnology, and diagnostics. Herein, we describe VLP production in different systems as well as its applications in biology and medicine.

Human papillomavirus in the HIV-infected host: epidemiology and pathogenesis in the antiretroviral era

Human papillomavirus (HPV) infection is associated with essentially all cervical cancers, 80-90 % of anal cancers, and a high proportion of oropharyngeal, vaginal, penile, and vulvar cancers. Malignancy is preceded by the development of precancerous lesions termed high-grade squamous intraepithelial lesions (HSIL). Men and women with human immunodeficiency virus (HIV) infection are at high risk of HPV-related malignancies. The incidence of anal cancer in particular has markedly risen during the antiretroviral era due to the increased longevity of patients with HIV and the absence of anal malignancy screening programs. HIV infection may facilitate initial HPV infection by disrupting epithelial cell tight junctions. Once infection is established, HIV may promote HSIL development via the up-regulation of HPV oncogene expression and impairment of the immune response needed to clear the lesion. HIV-infected women should be screened for cervical HSIL and cancer, and HIV-infected men and women should be considered for anal screening programs.

How to assess the binding strength of antibodies elicited by vaccination against HIV and other viruses

Vaccines that protect against viral infections generally induce neutralizing antibodies. When vaccines are evaluated, the need arises to assess the affinity maturation of the antibody responses. Binding titers of polyclonal sera depend not only on the affinities of the constituent antibodies but also on their individual concentrations, which are difficult to ascertain. Therefore an assay based on chaotrope disruption of antibody-antigen complexes was designed for measuring binding strength. This assay works well with many viral antigens but gives differential results depending on the conformational dependence of epitopes on complex antigens such as the envelope glycoprotein of HIV-1. Kinetic binding assays might offer alternatives, since they can measure average off-rate constants for polyclonal antibodies in a serum. Here, potentials and fallacies of these techniques are discussed.

A Live Vector Expressing HPV16 L1 Generates an Adjuvant-Induced Antibody Response In-vivo

Background:

The association between human papillomavirus (HPV) infections and cervical cancer has suggested the design of prophylactic and therapeutic vaccines against genital warts. The HPV capsid has made of two L1 and L2 coat proteins that have produced late in viral infections. Regarding to the recent studies, two commercial prophylactic vaccines have based on L1 viral like particles (VLPs) could strongly induce antibody responses, and protect human body from HPV infections. However, the use of these HPV vaccines has hindered due to their high cost and some limitations. Currently, among various vaccination strategies, live vector-based vaccines have attracted a great attention.

Objectives:

Herein, a non-pathogenic strain of the protozoan organism known as Leishmania tarentolae has utilized to induce potent humoral immunity in mice model.

Materials and Methods:

At first, cloning of HPV16 L1 gene into Leishmania expression vector has performed and confirmed by PCR and digestion with restriction enzymes. The promastigotes of Leishmania tarentolae (L.tar) have transfected with linearized DNA construct by electroporation. Protein expression has analyzed by SDS-PAGE and western blotting. Then, the immunogenicity of leishmania expressing L1 protein (L.tar-L1) has assessed in mice model.

Results:

Our data has indicated that subcutaneous immunization of mice with the recombinant L.tar-L1 has led to enhance the levels of IgG1 and lgG2a in comparison with control groups. Furthermore, there was no significant increase in antibody levels between two and three times of immunizations.

Conclusions:

The recombinant live vector was able to induce humoral immunity in mice without need of any adjuvant. However, further studies have required to increase its efficiency.

Intramuscular Priming and Intranasal Boosting Induce Strong Genital Immunity Through Secretory IgA in Minipigs Infected with Chlamydia trachomatis

International efforts in developing a vaccine against Chlamydia trachomatis have highlighted the need for novel immunization strategies for the induction of genital immunity. In this study, we evaluated an intramuscular (IM) prime/intranasal boost vaccination strategy in a Göttingen Minipig model with a reproductive system very similar to humans. The vaccine was composed of C. trachomatis subunit antigens formulated in the Th1/Th17 promoting CAF01 adjuvant. IM priming immunizations with CAF01 induced a significant cell-mediated interferon gamma and interleukin 17A response and a significant systemic high-titered neutralizing IgG response. Following genital challenge, intranasally boosted groups mounted an accelerated, highly significant genital IgA response that correlated with enhanced bacterial clearance on day 3 post infection. By detecting antigen-specific secretory component (SC), we showed that the genital IgA was locally produced in the genital mucosa. The highly significant inverse correlation between the vaginal IgA SC response and the chlamydial load suggests that IgA in the minipig model is involved in protection against C. trachomatis. This is important both for our understanding of protective immunity and future vaccination strategies against C. trachomatis and genital pathogens in general.

Human papillomavirus vaccination in HIV-infected women: need for increased coverage

Human immunodeficiency virus (HIV)-infected women carry a significant burden on human papillomavirus (HPV) infection and associated diseases. As HIV-infected individuals are living longer, the prevalence of HPV infection is rising and HPV-associated cytological abnormalities remain high despite successful treatments of HIV infection. Several HPV vaccines are currently available and recommended for adolescents and adults up to age 26. The vaccines are safe, immunogenic and effective in preventing diseases due to HPV types included in the vaccines, particularly among persons without prior HPV exposure. This review summarizes available data on the use of the HPV vaccines among HIV-infected women. The immunogenicity and safety of the vaccines are highlighted and in particular, barriers to vaccination among HIV-infected women are discussed.

Persistent infection with high-risk human papilloma viruses: cohort study, Mérida, Venezuela

Cervical lesions have been associated with infection by high-risk human papilloma virus (high-risk HPV). In 409 women aged >15 years high-risk HPV lesions were identified. In a cohort of this population persistent infection was compared with cytological, colposcopic, and histological lesions. Cervical scrapes were taken and DNA was isolated. HPV was detected by PCR in the E6/E7 region. Genotyping was performed by PCR nested multiple E6/E7. HPV was detected in a 37.40% (153/409), high-risk HPV in 86% (153/178), HPV18 46.64% (83/178), HPV16 34.28% (61/178). Among these 53.93% (96/178) were multiple infections, and HPV18/16 (30/96) was the most frequent 31.25%. The cytology showed changes in 15% of positive patients. A 49.67% in women positive for HPV infection showed abnormalities in the colposcopic study, a relationship that turned out to be statistically significant ( p < 0.0019 test χ²). Among all 85% of the women were younger than 45 years of age. Fifty-seven patients were evaluated 15 months after the base study, with initial prevalence of morbidity 49.12% (28/57) and at the end 10.53% (6/57), showing in 89.29% (25/28) negative for HR-HPV infection, 10.34% (3/28) showed persistence of infection, 17.54% (10/57) presented cytological alterations, with 80% of positivity for HPV, and a regression of 100% (10/10) of the previously identified lesions. With colposcopy, 50% (14/28) presented alterations related to HPV, of these 85.71% (12/14) showed regression of such an alteration. The cumulative incidence for HPV was 10.34% (3/29). The incidence rate was 4.23% (3/71), which is equal to 4.23 new cases of HPV infection per 100 people, per year of follow-up. In conclusion, the present work shows a high frequency of infection by high-risk HPV, with predominance of HPV18 and 16 and in general for multiple infections. Colposcopy was better predictor than the Pap smear for infection. The follow-up study revealed a low percentage of persistent infection, and a high frequency of negativity for viral infection, high regression of cytological and colposcopic lesions, a low cumulative and incidence rate similar to that reported by other Latin American countries and higher than the European countries.

Delivery strategies to enhance oral vaccination against enteric infections

While the majority of human pathogens infect the body through mucosal sites, most licensed vaccines are injectable. In fact the only mucosal vaccine that has been widely used globally for infant and childhood vaccination programs is the oral polio vaccine (OPV) developed by Albert Sabin in the 1950s. While oral vaccines against Cholera, rotavirus and Salmonella typhi have also been licensed, the development of additional non-living oral vaccines against these and other enteric pathogens has been slow and challenging. Mucosal vaccines can elicit protective immunity at the gut mucosa, in part via antigen-specific secretory immunoglobulin A (SIgA). However, despite their advantages over the injectable route, oral vaccines face many hurdles. A key challenge lies in design of delivery strategies that can protect antigens from degradation in the stomach and intestine, incorporate appropriate immune-stimulatory adjuvants and control release at the appropriate gastrointestinal site. A number of systems including micro and nanoparticles, lipid-based strategies and enteric capsules have significant potential either alone or in advanced combined formulations to enhance intestinal immune responses. In this review we will outline the opportunities, challenges and potential delivery solutions to facilitate the development of improved oral vaccines for infectious enteric diseases.