Papillomavirus Research最新文献

Objective

To determine the extent to which human rights considerations influence the attitudes of healthcare providers in Brazil with regard to access to the human papillomavirus (HPV) vaccine for females over 13 and males of all ages.

Methods

From May to August 2015, we conducted a cross-sectional study among healthcare providers in eight public health clinics in the city of Mauá, Brazil. Frequency analysis was conducted across three subject areas: access, knowledge, and attitudes.

Results

A total of 154 surveys were analyzed. Providers reported their perception that Brazilians do not have equal access to health (80%) and the vaccine exclusions limit an individual's right to health (72%). Providers stated it is medically effective to vaccinate females over the age of 13 (77%), these females should be vaccinated (84%), and they would vaccinate them (82%). Similar responses were reported for males.

Conclusion

Cervical cancer is the 4th leading cause of cancer among females in Brazil. Most cervical cancer cases are caused by persistent HPV infection, preventable through HPV vaccination. Limiting access to the HPV vaccine when medically efficacious is a perceived infringement of an individual's right to health. Brazil has a constitutional responsibility to reduce these access barriers.

Background

Some studies on human papillomavirus (HPV) provide not only type-specific incidence rates (IR), but also IRs of HPV groupings (e.g. the nonavalent grouping). We made an inventory of the different approaches used to calculate such IRs and assessed their impact on the estimated IRs of HPV groupings.

Methods

We performed a systematic review assessing all approaches used in literature to estimate IRs. Subsequently we applied these approaches to data of a Dutch cohort study on HPV in men who have sex with men (H2M). IRs were estimated for six different HPV groupings.

Results

The systematic review yielded six different approaches (A-F) for estimating the IRs, varying in exclusion criteria at baseline, and the definitions of an incident event and person-time. Applying these approaches to the H2M dataset (n = 749), we found differences in the number of participants at risk, number of incidents events, person-time, and IR. For example, for the nonavalent grouping, depending on the approach chosen, the IR varied between 3.09 and 6.54 per 100 person-months.

Conclusion

In published studies different epidemiological assumptions are used to estimate IRs of grouped HPV types, leading to widely differing estimates of IRs. IRs between different studies may therefore not be comparable.

Background

In a 2012 pilot, 9111 Mongolian girls aged 11–17 years received three doses of the quadrivalent (4vHPV) vaccine, Gardasil^®. This is the first study to measure early vaccine effectiveness and assess knowledge and attitudes of young women in Mongolia in relation to the human papillomavirus (HPV), the vaccine and cervical cancer.

Methods

A cohort of women vaccinated in 2012 (n = 726) and an unvaccinated cohort (n = 790) provided self-administered vaginal swabs for detection of high-risk HPV genotypes 16, 18/45, 31, 33, 35, 39, 51, 52, 56, 58, 59, 66, 68 five years following vaccination. Participant knowledge and attitudes were assessed through a questionnaire.

Results

A total of 1882 questionnaires and 1516 self-administered vaginal swabs were analyzed. The prevalence of any HRHPV was 39.5% among both cohorts. The prevalence of vaccine-targeted HPV types was significantly lower in the vaccinated cohort than unvaccinated: 4.8% and 17.2% respectively. The 4vHPV was shown to be protective against HRHPV 16, 18/45 with 75% vaccine effectiveness. Participant knowledge was low.

Conclusions

This study demonstrates that the 4vHPV is associated with reduced vaccine-targeted HPV detection rates in young Mongolian women. The questionnaire results highlight a need for awareness-raising initiatives in Mongolia on HPV, the vaccine and cervical cancer.

Aim

Prophylactic human papillomavirus (HPV) vaccines are highly effective at preventing pre–cancerous cervical lesions when given in a three–dose schedule. Some post–hoc trial data suggest that one dose prevents HPV infection. If one dose could prevent pre–cancerous cervical lesions, then global cervical cancer prevention would be greatly facilitated. We assessed the effectiveness of quadrivalent HPV vaccine by number of doses against cervical intraepithelial neoplasia (CIN) 2 or 3/adenocarcinoma–in–situ (AIS)/cancer in Australia up to seven years post vaccination.

Methods

We linked registry data from all 8 jurisdictional cervical screening registers, with the national HPV vaccination register, death index and cancer registers for all Australian women aged 15 or under when eligible for vaccine who screened between April 2007 (when vaccination commenced) and 31 December 2014. We performed Cox proportional hazard regression, adjusted a priori for age, socioeconomic status, and area of residence, to estimate hazard ratios of histologically confirmed CIN2/CIN3/AIS/cancer.

Results

We included 250,648 women: 48,845 (19·5%) unvaccinated, 174,995 (69·8%) had received three doses, 18,190 (7·3%) two doses and 8,618 (3·4%) one dose. The adjusted hazard ratio was significantly lower for all dose groups compared to unvaccinated women (1 dose 0·65 (95%CI 0·52–0·81), 2 doses 0·61 (0·52–0·72) and 3 doses 0·59 (0·54–0·65).) With adjustment for age at vaccination amongst the vaccinated group, the adjusted hazard ratios for one dose and two dose recipients were comparable to three dose recipients (one dose 1.01 (95%CI 0.81–1.26), two doses 1.00 (0.85–1.17).) Multiple sensitivity analyses, including use of different dose assignment methods, produced consistent findings. Comparison with a historical cohort of age matched women showed that the result was not due to herd protection alone.

Conclusions

One dose had comparable effectiveness as two or three doses in preventing high–grade disease in a high coverage setting. These findings support the hypothesis that one dose vaccination may be a viable strategy when working towards the global elimination of cervical cancer.

Persons with HIV are at increased risk of HPV infection, HPV disease, and HPV-related cancers compared to HIV negative persons. In persons with HIV, immune responses to vaccination are often sub-optimal, and while these improve with ART, they often remain lower and decline more rapidly than in HIV-negative individuals. Although the evidence base to support the immunogenicity of HPV vaccines in HIV + ve persons is reasonable, the evidence base to support the efficacy of HPV vaccines in HIV + ve individuals is inconsistent. There is one study in HIV + ve men who have sex with men (MSM) which showed no effect, and two other studies, one in HIV + ve women and one in HIV + ve adolescents that showed reduced effectiveness. All these effectiveness studies used Gardasil 4 (G4). Two studies in HIV + ve persons have shown superior immunogenicity of Cervarix (which uses a TLR4 agonist adjuvant) compared to G4. Studies of Hepatitis B vaccines in HIV + ve persons have shown that either (i) increased number of doses (ii) increased vaccine dose, or (iii) TLR agonist adjuvanted vaccines, all produce increased immunogenicity compared to standard vaccine regimes. Therefore, questions remain as to optimal HPV vaccine regimes in HIV and further clinical trials with different HPV vaccine regimes are needed.

Background

Human Papillomavirus (HPV) infection is well established in oropharyngeal squamous cell carcinoma (OPSCC) and cervical cancer (CC). However, the association between both HPV related cancers remains unclear. The purpose of this study was to investigate the association between HPV related cancers of the oropharynx and cervix.

Methods

A provincial cancer registry was used to retrospectively identify all patients diagnosed with OPSCC from 1997-2015. The standardized incidence ratio (SIR) of CC history in women with p16+/-OPSCC was measured.

Results

From 372 women with OPSCC included, the SIR of CC was significantly higher across all ages compared to the general population in Alberta, Canada (p < 0.0001).

Conclusions

Women with HPV/p16+ OPSCC have a significantly higher risk of CC compared to the general population.

The linear reverse blotting assays are valid methods for accurate human papillomavirus (HPV) typing required to manage women at risk of developing cervical cancer. However, some samples showed a positive signal in HPV lines but failed to display a positive signal in subsequent typing lines (designated as HPV-X), which indicate that certain types were not available on the respective typing blots. The aim of this study is to elucidate the types or variants of HPV through the high-throughput sequencing (HTS) of 54 ASCUS cervical samples in which the viruses remained untypeable with INNO LiPA HPV^® assays. Low-risk (LR)-HPV types (HPV6, 30, 42, 62, 67, 72, 74, 81, 83, 84, 87, 89, 90 and 114), high-risk (HR)-HPV35 and possibly (p)HR-HPV73 were detected among HPV-X. Individual multiple infections (two to seven types) were detected in 40.7% of samples. Twenty-two specimens contained variants characterised by 2–10 changes. HPV30 reached the maximal number of 17 variants with relative abundance inferior or equal to 2.7%. The presence of L1 quasispecies explains why linear reverse blotting assays fail when variants compete or do not match the specific probes. Further studies are needed to measure the LR-HPV quasispecies dynamics and its role during persistent infection.

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.