Strong reduction in prevalence of HPV16/18 and closely related HPV types in sexually active adolescent women following the introduction of HPV vaccination in Argentina

Prevalence of Human Papilloma Virus in Coquimbo, Chile

BACKGROUND

Human papillomavirus (HPV) is the main pathogen responsible of cervical cancer. The characterization of HPV genotypes in preneoplastic lesions and cervical cancer could establishes the effectiveness of the vaccination plan in the Chilean population. The aim of this study was to determine the frequency of HPV in women in the Coquimbo region.

METHODS

A total of 1235 cervical samples from women aged 20-64 years old who attended gynecological check-ups from April 2023 to July 2024 were analyzed to detect HPV genotypes using qPCR.

RESULTS

The overall prevalence rate of HPV infection was 26.56 %, while the prevalence of HR-HPV in age groups G1 (20-29 years) and G2 (30-64 years) was 47.69 % and 24.07 %, respectively. The most prevalent genotypes of HPV infection among our entire population were HPV16, HPV51 and HPV 31. Single infection (74.70 %) was the main pattern of HPV infection observed in the entire group, followed by double infection (16.46 %) and multiple infection (8.84 %), which was similar in Group 2, with percentiles of 76.07 %, 15.79 % and 7.14 %, respectively. However, in Group 1 a higher frequency of multiple HPV infections was observed, with 16.13 %.

CONCLUSION

This HPV prevalence infections among women in the Coquimbo region appears to be higher than the reported in Chile. In the rest of country, HPV prevalence is likely underestimated. Molecular detection of 14 HR-HPV genotypes is important because it will not only help women avoid cervical cancer but could also inform the introduction of new vaccines targeting a broader spectrum of HR-HPV.

Prevalence of non-vaccine high-risk HPV cervical infections in vaccinated women: a systematic review and meta-analysis

BACKGROUND

Human Papillomavirus (HPV) is the most common sexually transmitted lower genital tract infection worldwide and the main etiological factor of cervical cancer (CC). Since 2006, vaccines have been implemented to reduce CC-related morbidity and mortality. This systematic review and meta-analysis aimed to evaluate the prevalence of cervical infections by non-vaccine high-risk HPV (HR-HPV) types in women vaccinated against types 16 and 18.

METHOD

This systematic review and meta-analysis used independent electronic databases - Lilacs, WHO, BDENF, State Department of Health SP, Health Information Locator, IRIS, Coleciona Sistema Único de Saúde, BINACIS, IBECS, CUMED and SciELO, on July 14, 2023. Observational studies that evaluated vaccinated and unvaccinated women against HR-HPV and the prevalence of cervical infection by types of HR-HPV were included. Intervention effects were expressed as prevalence ratios (PR). Forest plots were used to visualize vaccination effects. The study protocol was previously registered in PROSPERO, under code CRD42023440610.

RESULTS

Of the 7,051 studies, 31 met the analysis criteria. A total of 59,035 women were eligible for this systematic review. The results showed a high prevalence of non-vaccine HR-HPV types, regardless of vaccination status. For HPV 31/33/45 (PR = 0.60 [0.40-0.91]), HPV31 (PR = 0.47 [0.31-0.72]), and HPV 45 (PR = 0.38 [0.22-0.69]), a positive random effect was found.

CONCLUSION

The prevalence of non-vaccine HR-HPV cervical infection was high in women, regardless of vaccination status. For HPV types 31 and 45 and 31/33/45, the prevalence was lower in vaccinated women, suggesting a cross-protective effect of vaccines for these viral types.

How has post-implementation surveillance of high-coverage vaccination with HPV16/18-AS04 vaccine in England added to evidence about its cross-protective effects?

BACKGROUND

Bivalent human papillomavirus HPV16/18-AS04 vaccine (Cervarix, GSK) offers direct protection against HPV16/18. Results from randomised controlled trials showed cross protective effects and suggested that declines in some closely related HPV types could be expected in a population with high vaccination coverage.

AIM

To evaluate the evidence for cross-protection afforded by HPV16/18-AS04 from post-implementation surveillance in England, and how this complements clinical trial data and post-implementation observations in other countries.

METHODS

Evidence of cross-protection in young women offered vaccination with HPV16/18-AS04 was gathered from HPV surveillance in England. Data from clinical trials and other post-implementation studies were reviewed.

RESULTS

Surveillance using anonymised residual specimens in England found declines of 52.3%, 67.4% and 33.3% against grouped HPV-31/33/45 in 16-18, 19-21, and 22-24 year olds, respectively. Additionally, type-specific analysis found that the prevalence of HPV31 declined to below 1% across all age groups. Cross-protection has been monitored and maintained for over 10 years since the introduction of the vaccination programme. Cross-protection against HPV6/11 was not found in English surveillance outcomes.

CONCLUSION

Surveillance of type-specific infections in vaccine-eligible populations in England has generated clear evidence of cross-protective effects from HPV16/18-AS04 vaccination against high-risk HPV 31/33/45 infections, consistent with other post-implementation observations and confirming and in some ways exceeding expectations from clinical trials.

[Ranking of immunization programs in Latin America, 2020Ranking dos programas de vacinação na América Latina, 2020]

Objective

Construct a ranking of national immunization programs in Latin America in 2020 and compare it with the previous year.

Methods

Eighteen national immunization programs were evaluated on the basis of public information obtained from official sites of the countries' ministries of health, the World Health Organization, the Pan American Health Organization, the United Nations Children's Fund, and local sources. The ranking was based on the 2020 vaccination schedule for different life stages, special situations, vaccination against influenza, 2019 vaccination coverage, and programmatic aspects.

Results

Vaccination coverage decreased in most countries. The average regional declined in 2020, as did the scores for most countries, except Chile and Colombia. Chile leads the ranking, followed by Uruguay, Panama, and Costa Rica. Chile stands out for its full calendar, higher vaccination coverage rates, and programmatic achievements.

Conclusions

The lower overall score in 2020 highlights the need to recover the Region's vaccination coverage rates. This analysis seeks to motivate countries to address pending challenges.

Human papillomavirus genotyping using next generation sequencing (NGS) in cervical lesions: Genotypes by histologic grade and their relative proportion in multiple infections

Sensitive and specific genotyping of human papillomaviruses (HPVs) is critical for the surveillance and monitoring of the vaccine effectiveness. Here, HPV genotypes were identified in 137 cervical samples with different histology (79 ≤CIN1 and 58 CIN3+) using Nested-PCR followed by Next-Generation sequencing (NGS) and relative proportions for each genotype in multiple infections were computed. All samples had been previously genotyped by PCR-Reverse Blotting Hybridization (PCR-RBH) thus allowing for a concordance analysis between both techniques. Multiple infections were present in 85% of ≤CIN1 cases compared to only 41% in CIN3+ cases (p<0.001). Among ≤CIN1 cases a towering genotypic diversity was observed, considering both low (LR-) and high risk (HR-) HPV genotypes; while among CIN3+, diversity was lower, HR-HPVs prevailing in most cases, especially HPV16. Furthermore, the predominance of HR-HPV genotypes in the proportions identified in each sample was higher in CIN3+ cases [(HPV16 (62.5%), followed by HPV31 and HPV58 (8.3% each)], than in ≤CIN1 cases [(HPV16 (17.7%), followed by HPV52 (14.7%) and HPV31 (10.3%)]. Agreement between PCR-RBH and NGS was higher than 90% for all genotypes (with an overall Kappa of 0.7), even though NGS identified eighty-nine positive results for HPV genotypes that had not been detected by PCR-RBH, evidencing its greater sensitivity. These results suggest that a reduction in genotypic diversity and/or an increase in the relative proportion of HR-HPVs in multiple infections can be considered as a biomarker for the potential risk of malignant progression.

HPV vaccine introduction in the Americas: a decade of progress and lessons learned

INTRODUCTION

Human papillomavirus (HPV) is an important public health concern due to its causative role in many cancers, especially cervical cancer, and other conditions that lead to serious health consequences in both men and women. In Latin America and the Caribbean, nearly 60,000 new cases of cervical cancer and another 7,000 HPV-associated cancers are diagnosed annually.

AREAS COVERED

HPV vaccination combined with comprehensive cervical cancer control programmingis paving the way for eliminating cervical cancer as a major public health problem and drastically reducing other HPV-associated diseases. To date, 44 countries and territories in the Americas have introduced HPV vaccines as part of their national immunization programs and cervical cancer control strategies. Early lessons from HPV vaccine introduction suggest that transparent and credible evidence-based decision-making, information, education and communication about HPV and cervical cancer, coordination with existing cervical cancer control initiatives, and precise planning for ensuring effective uptake of the vaccine in target groups are all critical elements of success.

EXPERT OPINION

There is an urgent need for strategies to increase HPV vaccine coverage, and as the integrated control programs evolve and other HPV-associated disease becomes important for public health, there will be a need for continued program and policy evaluation.

Distribution of human papillomavirus genotypes by severity of cervical lesions in HPV screened positive women from the ESTAMPA study in Latin America

The proportion of HPV16 and 18-associated cervical cancer (CC) appears rather constant worldwide (≥70%), but the relative importance of the other HR-HPV differs slightly by geographical region. Here, we studied the HPV genotype distribution of HPV positive Latin American (LA) women by histological grade, in a sub-cohort from the ESTAMPA study; we also explored the association of age-specific HPV genotypes in severe lesions. Cervical samples from 1,252 participants (854 ≤CIN1, 121 CIN2, 194 CIN3 and 83 CC) were genotyped by two PCRs-Reverse Blotting Hybridization strategies: i) Broad-Spectrum General Primers 5+/6+ and ii) PGMY9/11 PCRs. HPV16 was the most frequently found genotype in all histological grades, and increased with the severity of lesions from 14.5% in ≤ CIN1, 19.8% in CIN2, 51.5% in CIN3 to 65.1% in CC (p < 0.001). For the remaining HR-HPVs their frequency in CC did not increase when compared to less severe categories. The nonavalent vaccine HR-types ranked at the top in CC, the dominant ones being HPV16 and HPV45. HR-HPV single infection occurs, respectively, in 57.1% and 57.0% of ≤CIN1 and CIN2, increasing to 72.2% and 91.6% in CIN3 and CC (p<0.001). No association between age and HPV type was observed in CC, although the risk of HPV16 infection in CIN3 cases increased with age. Results confirm the relevance of HPV16 in the whole clinical spectrum, with a strong rise of its proportion in CIN3 and cancer. This information will be relevant in evaluating the impact of HPV vaccination, as a baseline against which to compare genotype changes in HPV type-specific distribution as vaccinated women participate in screening in LA region. Likewise, these data may help select the best HPV testing system for HPV-based efficient, affordable, and sustainable screening programmes.

Genetic variation in the E6 and E7 genes of human papillomavirus type 16 in northeastern Argentina

The province of Misiones is considered a region with a high mortality rate due to cervical cancer (CC). To gain insight into this problem, we explored the association between genetic variation in the E6 and E7 oncogenes of HPV16 and the risk of CC. We studied 160 women with cytological diagnoses of negative for intraepithelial lesion or malignity, low-grade squamous intraepithelial lesion, and high-grade squamous intraepithelial lesion/CC and a positive test for HPV16 infection. The genetic characterization of E6 and E7 genes was undertaken through PCR amplification and direct Sanger sequencing. Phylogenetic classification was conducted using Bayesian methods. To estimate the odds ratio (OR) for an association between genetic variants in the E6 and E7 genes and the risk of CC, we used ordinal logistic regression adjusted by age. The final data set comprised 112 samples. Diagnostic single-nucleotide polymorphisms (SNPs) and phylogenetic trees confirmed the presence of Lineage A (95.5%) and D (4.5%) in the samples. For the E6 gene, we identified eleven different sequences, with the most common ones being Lineage A E6 350G (58.9%) and E6 350T (37.5%). The E6 350G was associated with progression to HSIL/CC, with an OR of 19.41 (4.95-76.10). The E7 gene was more conserved than E6, probably due to the functional constraints of this small protein. Our results confirmed the association of the E6 350G SNP with a higher risk of developing CC. These data will contribute to understanding the biological bases of CC incidence in this region.

Monitoring HPV vaccine impact on cervical disease: Status and future directions for the era of cervical cancer elimination

Post-licensure monitoring of the impact of HPV vaccines is critical to track the progress being made toward cervical cancer elimination and to identify areas where further progress can accelerate the achievement of this important public health goal. Over the past decade, a large body of evidence has revealed convincing benefits of HPV vaccination in preventing cervical infections and precancers at the individual-level (i.e., direct effectiveness) as well as in reducing the population-level burden of disease (i.e., overall effectiveness). At this time, effectiveness of the vaccines on preventing cervical cancer is just beginning to emerge given that there is a prolonged latency period for invasive disease. As we enter the era of cervical cancer elimination, these early and promising results may be expected in other countries in the near future. Thus, monitoring the direct and overall effectiveness for cervical cancer is an urgent research priority. In this article, we summarize what is known about the effectiveness of HPV vaccines on precancerous outcomes, and we highlight considerations for continuing these important public health activities going forward to monitor progress toward cervical cancer elimination.