Effectiveness of HPV vaccination in women reaching screening age in Italy

Knowledge and Practices Regarding Human Papillomavirus and Cervical Cancer Screening Among Women in Low-Income Areas of China: A Cross-Sectional Study

BACKGROUND

Persistent human papillomavirus (HPV) infection is the primary cause of cervical cancer. However, this can be prevented through vaccination and screening. This study aimed to clarify the relationship between behavior, knowledge, and attitude toward cervical cancer and regular screening and HPV infection among women in Lueyang County.

METHODS

Women who underwent cervical cancer screening at the outpatient department of a maternal and child health center between September and December 2021 were invited to participate. In total, 2,303 women completed the questionnaire. Women who underwent regular or irregular screening were 1:1 matched for age. Differences in knowledge of HPV and attitudes toward HPV vaccination among different populations were assessed. Logistic regression analysis was performed to identify the factors influencing HPV infection.

RESULTS

 In total, 417 pairs of women who underwent regular and irregular screening were successfully matched. Multivariate logistic regression results indicated that age is a risk factor for HPV infection (OR=1.056 95%CI: [1.031 1.082]), while regular screening acts as a protective factor against HPV infection (OR=0.174 95%CI: [0.117 0.259]). Additionally, regular screening was associated with a higher level of knowledge about HPV among women compared to those who did not undergo regular screening (p<0.001).

CONCLUSIONS

 Women in Lueyang County have low levels of knowledge regarding HPV and cervical cancer. Regular screening is a protective factor against HPV infection. The regular screening group demonstrates a higher level of HPV knowledge compared with the irregular screening group. These findings highlight the importance of regular screening and the need to strengthen public health education.

Cervical cancer screening in high-altitude areas in China: A large cross-section study of 25,173 women in northern Tibet

Background

Cervical cancer has become a worldwide concern owing to its high incidence and mortality rates. To date, high-altitude areas of Tibet have not benefited from any large-scale cervical cancer screening programs. Therefore, we initiated a screening program to investigate the prevalence of human papilloma virus (HPV) and HPV genotype distribution to reveal cervical cancer and its precursor which lead to morbidity among women in the city of Nagqu in northern Tib3et.

Methods

A total of 25,173 women were recruited to undergo HPV genotype tests between June and December 2019. Women infected with HPV 16 and/or 18 underwent colposcopy and histological examination. Women with other high-risk HPV type (hr-HPV) underwent cytological tests to determine whether to conduct further colposcopy and histological examination for diagnosis. HPV prevalence was calculated in the total population and further stratified according to various parameters, such as age group, area location (altitude level), and single or mixed infection status. The HPV genotype distribution was also investigated accordingly. Cervical lesions revealed by further colposcopic findings were also analyzed; high-grade and malignant lesion morbidities were calculated in total and in each county. Most data were collected and analyzed using descriptive and consistency check statistical methods, and a risk factor investigation for HPV infection was performed using logistic regression models.

Results

The total HPV infection rate among women in Nagqu was 13.42%. Of the 25,173 women in the study, 999 (3.97%) were HPV 16/18 positive, 2,379 (9.45%) were other hr-HPV-positive, and 21,795 (86.58%) were HPV-negative. The five most common HPV genotypes, accounting for more than 60% of all HPV infections in Nagqu people, were HPV 16, 58, 31, 18, and 52. Tibetan women younger than 20 years and older than 60 years were the two age groups with the highest rates of HPV infection, 26.7% and 19.8%, respectively. Among the HPV-positive women, 2,656 (78.33%) were infected with a single strain and 732 (21.67%) were infected with multiple strains (more than two genotypes). HPV prevalence increased in high-altitude areas (positive rate highest in Nyima with an altitude of 5,000 m, 23.9%) and decreased in relatively low-altitude areas (positive rate lowest in Lhari with an altitude of 4,000 m, 6.6%). Multiple analyses showed that age, parity, age at first delivery, and altitude of residence were independent factors facilitating HPV infection in Tibetan women. High-grade and malignant cervical lesions revealed by histological findings were different among living locations, with the highest rates in Xainza, Baingoin, and Nyainrong, these being 2.019%, 1.820%, and 1.116%, respectively, among women in these areas.

Conclusion

Our survey provides an overall perspective on HPV genotype infection and cervical lesions in women in northern Tibet. The data not only provide useful information for the treatment of cervical lesions but also has great value in terms of the primary and secondary prevention measures that can be taken for women living in these regions.

Clinical Trial Registration

www.chictr.org.cn, indentifier ChiCTR2000035061.

Quadrivalent Human Papillomavirus Vaccine Effectiveness after 12 Years in Madrid (Spain)

A fully government-funded human papillomavirus (HPV) vaccination program started in 2007 in Spain (only 11–14-year-old girls). The first of those vaccinated cohorts, with the quadrivalent vaccine (Gardasil), turned 25 years old in 2018, the age at which cervical cancer screening begins in Spain. The current study could provide the first evidence about the effectiveness of the quadrivalent vaccine against HPV in Spain and the influence of age of vaccination. The present ambispective cohort study, which was conducted on 790 women aged 25 and 26 years old, compares the rate of HPV prevalence and cytologic anomaly according to the vaccination status. The overall infection rate was 40.09% (vaccinated group) vs. 40.6% (non-vaccinated group). There was a significant reduction in the prevalence of HPV 6 (0% vs. 1.3%) and 16 (2.4% vs. 6.1%), and in the prevalence of cytological abnormalities linked to HPV16: Atypical Squamous Cells of Undetermined Significance (ASCUS) (2.04% vs. 14%), Low-grade Squamous Intraepithelial Lesions (LSIL) (2.94% vs. 18.7%) and High-grade Squamous Intraepithelial Lesion (HSIL) (0% vs. 40%), in the vaccinated group vs. the non-vaccinated group. Only one case of HPV11 and two cases of HPV18 were detected. The vaccine effectively reduces the prevalence of vaccine genotypes and cytological anomalies linked to these genotypes.

Are We Facing a New Colposcopic Practice in the HPV Vaccination Era? Opportunities, Challenges, and New Perspectives

The combination of primary and secondary prevention has already influenced the colposcopic practice by reduction in HPV (human papillomavirus) vaccine-type HSIL (HIGH-GRADE SIL), colposcopy referral numbers, colposcopic positive predictive value (PPV) for CIN2+, and by modification of referral pattern, colposcopic performance, and procedures. Different strategies, both isolated and combined, have been proposed in order to maintain the diagnostic accuracy of colposcopy: patient risk stratification based on immediate or future risk of CIN3+ or on HPV genotyping after a positive screening test. Data are needed to support alternative colposcopic strategies based on vaccination status and on the application of artificial intelligence where the patient's risk stratification is implicit in precision medicine which involves the transition from an operator-dependent morphology-based to a less-operator dependent, more biomolecular management. The patient's risk stratification based on any combination of "history" and "test results" to decrease colposcopy workload further reduce colposcopic and histologic morphological approaches, while adding genotyping to the risk stratification paradigm means less cytologic morphologic diagnosis. In Italy, there is a strong colposcopic tradition and there is currently no immediate need to reduce the number of colposcopies. Instead, there is a need for more accredited colposcopists to maintain the diagnostic accuracy of colposcopy in the vaccination era.

Systematic literature review of cross-protective effect of HPV vaccines based on data from randomized clinical trials and real-world evidence

BACKGROUND

The extent of cross-protection provided by currently licensed bivalent and quadrivalent HPV vaccines versus direct protection against HPV 31-, 33-, 45-, 52-, and 58-related disease is debated. A systematic literature review was conducted to establish the duration and magnitude of cross-protection in interventional and observational studies.

METHODS

PubMed and Embase databases were searched to identify randomized controlled trials (RCT) and observational studies published between 2008 and 2019 reporting on efficacy and effectiveness of HPV vaccines in women against non-vaccine types 31, 33, 45, 52, 58, and 6 and 11 (non-bivalent types). Key outcomes of interest were vaccine efficacy against 6- and 12-month persistent infection or genital lesions, and type-specific genital HPV prevalence or incidence. RCT data were analyzed for the according-to-protocol (bivalent vaccine) or negative-for-14-HPV-types (quadrivalent vaccine) efficacy cohorts.

RESULTS

Data from 23 RCTs and 33 observational studies evaluating cross-protection were extracted. RCTs assessed cross-protection in post-hoc analyses of small size subgroups. Among fully vaccinated, baseline HPV-naïve women, the bivalent vaccine showed statistically significant cross-protective efficacy, although with wide confidence intervals, against 6-month and 12-month persistent cervical infections and CIN2+ only consistently for HPV 31 and 45, with the highest effect observed for HPV 31 (range 64.6% [95% CI: 27.6 to 83.9] to 79.1% [97.7% CI: 27.6 to 95.9] for 6-month persistent infection; maximal follow-up 4.7 years). No cross-protection was shown in extended follow-up. The quadrivalent vaccine efficacy reached statistical significance for HPV 31 (46.2% [15.3-66.4]; follow-up: 3.6 years). Similarly, observational studies found consistently significant effectiveness only against HPV 31 and 45 with both vaccines.

CONCLUSIONS

RCTs and observational studies show that cross-protection is inconsistent across non-vaccine HPV types and is largely driven by HPV 31 and 45. Furthermore, existing data suggest that it wanes over time; its long-term durability has not been established.

Comparison of different human papillomavirus (HPV) vaccine types and dose schedules for prevention of HPV-related disease in females and males

BACKGROUND

Uptake of human papillomavirus (HPV) vaccine remains low in many countries, although the bivalent and quadrivalent HPV vaccines given as a three-dose schedule are effective in the prevention of precancerous lesions of the cervix in women. Simpler immunisation schedules, such as those with fewer doses, might reduce barriers to vaccination, as may programmes that include males.

OBJECTIVES

To evaluate the efficacy, immunogenicity, and harms of different dose schedules and different types of HPV vaccines in females and males.

SEARCH METHODS

We conducted electronic searches on 27 September 2018 in Ovid MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL) (in the Cochrane Library), and Ovid Embase. We also searched the WHO International Clinical Trials Registry Platform, and ClinicalTrials.gov (both 27 September 2018), vaccine manufacturer websites, and checked reference lists from an index of HPV studies and other relevant systematic reviews.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) with no language restriction. We considered studies if they enrolled HIV-negative males or females aged 9 to 26 years, or HIV-positive males or females of any age.

DATA COLLECTION AND ANALYSIS

We used methods recommended by Cochrane. We use the term 'control' to refer to comparator products containing an adjuvant or active vaccine and 'placebo' to refer to products that contain no adjuvant or active vaccine. Most primary outcomes in this review were clinical outcomes. However, for comparisons comparing dose schedules, the included RCTs were designed to measure antibody responses (i.e. immunogenicity) as the primary outcome, rather than clinical outcomes, since it is unethical to collect cervical samples from girls under 16 years of age. We analysed immunogenicity outcomes (i.e. geometric mean titres) with ratios of means, clinical outcomes (e.g. cancer and intraepithelial neoplasia) with risk ratios or rate ratios and, for serious adverse events and deaths, we calculated odds ratios. We rated the certainty of evidence with GRADE.

MAIN RESULTS

We included 20 RCTs with 31,940 participants. The length of follow-up in the included studies ranged from seven months to five years. Two doses versus three doses of HPV vaccine in 9- to 15-year-old females Antibody responses after two-dose and three-dose HPV vaccine schedules were similar after up to five years of follow-up (4 RCTs, moderate- to high-certainty evidence). No RCTs collected clinical outcome data. Evidence about serious adverse events in studies comparing dose schedules was of very low-certainty owing to imprecision and indirectness (three doses 35/1159; two doses 36/1158; 4 RCTs). One death was reported in the three-dose group (1/898) and none in the two-dose group (0/899) (low-certainty evidence). Interval between doses of HPV vaccine in 9- to 14-year-old females and males Antibody responses were stronger with a longer interval (6 or 12 months) between the first two doses of HPV vaccine than a shorter interval (2 or 6 months) at up to three years of follow-up (4 RCTs, moderate- to high-certainty evidence). No RCTs collected data about clinical outcomes. Evidence about serious adverse events in studies comparing intervals was of very low-certainty, owing to imprecision and indirectness. No deaths were reported in any of the studies (0/1898, 3 RCTs, low-certainty evidence). HPV vaccination of 10- to 26-year-old males In one RCT there was moderate-certainty evidence that quadrivalent HPV vaccine, compared with control, reduced the incidence of external genital lesions (control 36 per 3081 person-years; quadrivalent 6 per 3173 person-years; rate ratio 0.16, 95% CI 0.07 to 0.38; 6254 person-years) and anogenital warts (control 28 per 2814 person-years; quadrivalent 3 per 2831 person-years; rate ratio 0.11, 95% CI 0.03 to 0.38; 5645 person-years). The quadrivalent vaccine resulted in more injection-site adverse events, such as pain or redness, than control (537 versus 601 per 1000; risk ratio (RR) 1.12, 95% CI 1.06 to 1.18, 3895 participants, high-certainty evidence). There was very low-certainty evidence from two RCTs about serious adverse events with quadrivalent vaccine (control 12/2588; quadrivalent 8/2574), and about deaths (control 11/2591; quadrivalent 3/2582), owing to imprecision and indirectness. Nonavalent versus quadrivalent vaccine in 9- to 26-year-old females and males Three RCTs were included; one in females aged 9- to 15-years (n = 600), one in females aged 16- to 26-years (n = 14,215), and one in males aged 16- to 26-years (n = 500). The RCT in 16- to 26-year-old females reported clinical outcomes. There was little to no difference in the incidence of the combined outcome of high-grade cervical epithelial neoplasia, adenocarcinoma in situ, or cervical cancer between the HPV vaccines (quadrivalent 325/6882, nonavalent 326/6871; OR 1.00, 95% CI 0.85 to 1.16; 13,753 participants; high-certainty evidence). The other two RCTs did not collect data about clinical outcomes. There were slightly more local adverse events with the nonavalent vaccine (905 per 1000) than the quadrivalent vaccine (846 per 1000) (RR 1.07, 95% CI 1.05 to 1.08; 3 RCTs, 15,863 participants; high-certainty evidence). Comparative evidence about serious adverse events in the three RCTs (nonavalent 243/8234, quadrivalent 192/7629; OR 0.60, 95% CI 0.14 to 2.61) was of low certainty, owing to imprecision and indirectness. HPV vaccination for people living with HIV Seven RCTs reported on HPV vaccines in people with HIV, with two small trials that collected data about clinical outcomes. Antibody responses were higher following vaccination with either bivalent or quadrivalent HPV vaccine than with control, and these responses could be demonstrated to have been maintained for up to 24 months in children living with HIV (low-certainty evidence). The evidence about clinical outcomes and harms for HPV vaccines in people with HIV is very uncertain (low- to very low-certainty evidence), owing to imprecision and indirectness.

AUTHORS' CONCLUSIONS

The immunogenicity of two-dose and three-dose HPV vaccine schedules, measured using antibody responses in young females, is comparable. The quadrivalent vaccine probably reduces external genital lesions and anogenital warts in males compared with control. The nonavalent and quadrivalent vaccines offer similar protection against a combined outcome of cervical, vaginal, and vulval precancer lesions or cancer. In people living with HIV, both the bivalent and quadrivalent HPV vaccines result in high antibody responses. For all comparisons of alternative HPV vaccine schedules, the certainty of the body of evidence about serious adverse events reported during the study periods was low or very low, either because the number of events was low, or the evidence was indirect, or both. Post-marketing surveillance is needed to continue monitoring harms that might be associated with HPV vaccines in the population, and this evidence will be incorporated in future updates of this review. Long-term observational studies are needed to determine the effectiveness of reduced-dose schedules against HPV-related cancer endpoints, and whether adopting these schedules improves vaccine coverage rates.

The impact of 10 years of human papillomavirus (HPV) vaccination in Australia: what additional disease burden will a nonavalent vaccine prevent?

Background: A National human papilloma virus (HPV) Vaccination Programme for the prevention of HPV infection and associated disease using the quadrivalent HPV vaccine (4vHPV) has been funded and implemented in Australia since 2007, initially for girls only and extended to boys in 2013, with uptake rates among the highest observed worldwide. Aim: We report on the impact of this national programme on HPV prevalence and associated disease burden and estimate the potential impact of adopting a nonavalent HPV (9vHPV) vaccine. Methods: We performed a non-systematic literature review of studies measuring the burden of HPV-associated disease and infection in Australia before and after introduction of HPV vaccination. We also included key national reports with estimates of HPV-related disease burden. Results: Substantial declines in high-grade cervical disease and genital warts among vaccine-eligible women have been observed. Reductions in genital warts incidence and HPV prevalence among heterosexual men of similar age were observed before introduction of the male vaccination programme, indicating a substantial herd effect. 9vHPV vaccine is expected to prevent up to 90% of cervical and 96% of anal cancers. Of an estimated 1,544 HPV-associated cancers in 2012, 1,242 would have been preventable by the 4vHPV vaccine and an additional 187 anogenital cancers by the 9vHPV vaccine. Conclusions: Vaccination using 4vHPV vaccine has had a large demonstrable impact on HPV-related disease in Australia. A switch to 9vHPV could further reduce the HPV-associated cancer burden. With continued high coverage among both males and females, elimination of vaccine-type HPV disease seems achievable in Australia.

The prevalence, trends, and geographical distribution of human papillomavirus infection in China: The pooled analysis of 1.7 million women

Human papillomavirus (HPV) infection which continues to be the most common sexually transmitted disease, has been identified as a major risk factor for cervical cancer. Therefore, it is very important to understand and grasp the distribution of HPV in Chinese population, and make the foundation for the development of cervical cancer vaccine in China. An extensive search strategy was conducted in multiple literature databases. All retrieved studies were screened by October 31, 2018. The prevalence of HPV infection was analyzed using random effects model. A total of 68 studies satisfied the inclusion criteria for our study. The national overall prevalence of HPV infection was 15.54% (95% CI: 13.83%-17.24%). we also performed subgroup analysis by age, geographic location, level of economic development, HPV assay method, and type of HPV infection. The top 5 common HPV types detected in general population, were HPV 16 (3.52%, 95% CI: 3.18%-3.86%), 52 (2.20%, 95% CI: 1.93%-2.46%), 58 (2.10%, 95% CI: 1.88%-2.32%), 18 (1.20%, 95% CI: 1.05%-1.35%), and 33 (1.02%, 95% CI: 0.89%-1.14%). Except for the higher prevalence of HPV infection in 2009 and 2010, the prevalence of HPV infection in other years changed little, ranged from 13.2% to 17.4%. HPV type in Chinese women was quite distinctive. HPV infection played a critical role in the occurrence of cervical cancer, understanding the distribution of HPV type and performing the HPV type testing had important clinical value for colposcopy referral and increasing the detection rate. Therefore, our findings could provide evidence for cervical cancer screening and vaccine, in order to reduce the burden of cervical cancer.