Assessment of Human Papillomavirus Non-16/18, Type-Specific Risk for Cervical Intraepithelial Neoplasia Grade 3 or Worse Among Women With Cervical Atypical Glandular Cells.

OBJECTIVE: To evaluate the risk for cervical intraepithelial neoplasia grade 3 (CIN 3) or worse (including adenocarcinoma in situ [AIS] and invasive cervical cancer) associated with non-16/18 human papillomavirus (HPV) types (other HPV) among women with atypical glandular cells (AGC) in cervical cytology. METHODS: This population-based cohort study evaluates the risk of CIN 3 or worse associated with other HPV types. Human papillomavirus genotyping was performed on Pap tests collected in Sweden from 341 women with AGC that were positive for other HPV types from February 17, 2014, to December 31, 2018. The women were followed for histopathologic outcomes using comprehensive registry linkages until December 31, 2019. Cumulative incidence proportions of CIN 3 or worse by specific HPV type were calculated using 1-minus Kaplan-Meier function. Hazard ratios (HRs) for CIN 3 or worse were generated using multivariate Cox regression. RESULTS: Of 341 women, 134 (39.3%) had CIN 3-AIS, but there were only five (1.5%) women in the cohort with invasive cervical cancer. Human papillomavirus 45 preceded 80.0% of invasive cervical cancer cases. Among women positive for HPV33, 82.9% (95% CI 58.0-97.3%) had CIN 3 or worse during follow-up. Positivity for HPV31 conferred the highest HR for CIN 3 or worse relative to other types, both in primary cytology and primary HPV screening (HR 2.71, 95% CI 1.47-5.00 and HR 3.41, 95% CI 1.95-5.96, respectively). CONCLUSION: Among non-16/18 HPV types in AGC, HPV31 and 33 had the highest risk for CIN 3 or worse, whereas most of the women with invasive cancer were positive for HPV45. Extended HPV genotyping may be helpful for the management of AGC.

Assessment of bacterial and viral gut communities in healthy and tumoral colorectal tissue using RNA and DNA deep sequencing.

BACKGROUND: Colorectal cancer (CRC) is known to present a distinct microbiome profile compared to healthy mucosa. Non-targeted deep-sequencing strategies enable nowadays full microbiome characterization up to species level. AIM: We aimed to analyze both bacterial and viral communities in CRC using these strategies. MATERIALS & METHODS: We analyzed bacterial and viral communities using both DNA and RNA deep-sequencing (Novaseq) in colorectal tissue specimens from 10 CRC patients and 10 matched control patients. Following taxonomy classification using Kraken 2, different metrics for alpha and beta diversities as well as relative and differential abundance were calculated to compare tumoral and healthy samples. RESULTS: No viral differences were identified between tissue types, but bacterial species Polynucleobacter necessarius had a highly increased presence for DNA in tumors (p = 0.001). RNA analyses showed that bacterial species Arabia massiliensis had a highly decreased transcription in tumors (p = 0.002) while Fusobacterium nucleatum transcription was highly increased in tumors (p = 0.002). DISCUSSION: Sequencing of both DNA and RNA enables a wider perspective of micriobiome profiles. Lack of RNA transcription (Polynucleobacter necessarius) casts doubt on possible role of a microorganism in CRC. The association of F. nucleatum mainly with transcription, may provide further insights on its role in CRC. CONCLUSION: Joint assessment of the metagenome (DNA) and the metatranscriptome (RNA) at the species level provided a huge coverage for both bacteria and virus and identifies differential specific bacterial species as tumor associated.

Predicting past and future SARS-CoV-2-related sick leave using discrete time Markov modelling.

BACKGROUND: Prediction of SARS-CoV-2-induced sick leave among healthcare workers (HCWs) is essential for being able to plan the healthcare response to the epidemic. METHODS: During first wave of the SARS-Cov-2 epidemic (April 23rd to June 24th, 2020), the HCWs in the greater Stockholm region in Sweden were invited to a study of past or present SARS-CoV-2 infection. We develop a discrete time Markov model using a cohort of 9449 healthcare workers (HCWs) who had complete data on SARS-CoV-2 RNA and antibodies as well as sick leave data for the calendar year 2020. The one-week and standardized longer term transition probabilities of sick leave and the ratios of the standardized probabilities for the baseline covariate distribution were compared with the referent period (an independent period when there were no SARS-CoV-2 infections) in relation to PCR results, serology results and gender. RESULTS: The one-week probabilities of transitioning from healthy to partial sick leave or full sick leave during the outbreak as compared to after the outbreak were highest for healthy HCWs testing positive for large amounts of virus (ratio: 3.69, (95% confidence interval, CI: 2.44-5.59) and 6.67 (95% CI: 1.58-28.13), respectively). The proportion of all sick leaves attributed to COVID-19 during outbreak was at most 55% (95% CI: 50%-59%). CONCLUSIONS: A robust Markov model enabled use of simple SARS-CoV-2 testing data for quantifying past and future COVID-related sick leave among HCWs, which can serve as a basis for planning of healthcare during outbreaks.

Human exposome assessment platform.

The Human Exposome Assessment Platform (HEAP) is a research resource for the integrated and efficient management and analysis of human exposome data. The project will provide the complete workflow for obtaining exposome actionable knowledge from population-based cohorts. HEAP is a state-of-the-science service composed of computational resources from partner institutions, accessed through a software framework that provides the world's fastest Hadoop platform for data warehousing and applied artificial intelligence (AI). The software, will provide a decision support system for researchers and policymakers. All the data managed and processed by HEAP, together with the analysis pipelines, will be available for future research. In addition, the platform enables adding new data and analysis pipelines. HEAP's final product can be deployed in multiple instances to create a network of shareable and reusable knowledge on the impact of exposures on public health.

Multianalyte serology in home-sampled blood enables an unbiased assessment of the immune response against SARS-CoV-2.

Serological testing is essential to curb the consequences of the COVID-19 pandemic. However, most assays are still limited to single analytes and samples collected within healthcare. Thus, we establish a multianalyte and multiplexed approach to reliably profile IgG and IgM levels against several versions of SARS-CoV-2 proteins (S, RBD, N) in home-sampled dried blood spots (DBS). We analyse DBS collected during spring of 2020 from 878 random and undiagnosed individuals from the population in Stockholm, Sweden, and use classification approaches to estimate an accumulated seroprevalence of 12.5% (95% CI: 10.3%-14.7%). This includes 5.4% of the samples being IgG+IgM+ against several SARS-CoV-2 proteins, as well as 2.1% being IgG-IgM+ and 5.0% being IgG+IgM- for the virus' S protein. Subjects classified as IgG+ for several SARS-CoV-2 proteins report influenza-like symptoms more frequently than those being IgG+ for only the S protein (OR = 6.1; p < 0.001). Among all seropositive cases, 30% are asymptomatic. Our strategy enables an accurate individual-level and multiplexed assessment of antibodies in home-sampled blood, assisting our understanding about the undiagnosed seroprevalence and diversity of the immune response against the coronavirus.

Evaluation of 11 SARS-CoV-2 antibody tests by using samples from patients with defined IgG antibody titers.

We evaluated the performance of 11 SARS-CoV-2 antibody tests using a reference set of heat-inactivated samples from 278 unexposed persons and 258 COVID-19 patients, some of whom contributed serial samples. The reference set included samples with a variation in SARS-CoV-2 IgG antibody titers, as determined by an in-house immunofluorescence assay (IFA). The five evaluated rapid diagnostic tests had a specificity of 99.0% and a sensitivity that ranged from 56.3 to 81.6% and decreased with low IFA IgG titers. The specificity was > 99% for five out of six platform-based tests, and when assessed using samples collected ≥ 22 days after symptom onset, two assays had a sensitivity of > 96%. These two assays also detected samples with low IFA titers more frequently than the other assays. In conclusion, the evaluated antibody tests showed a heterogeneity in their performances and only a few tests performed well with samples having low IFA IgG titers, an important aspect for diagnostics and epidemiological investigations.

Performance indicators in breast cancer screening in the European Union: A comparison across countries of screen positivity and detection rates.

Comparable performance indicators for breast cancer screening in the European Union (EU) have not been previously reported. We estimated adjusted breast cancer screening positivity rate (PR) and detection rates (DR) to investigate variation across EU countries. For the age 50-69 years, the adjusted EU-pooled PR for initial screening was 8.9% (cross-programme variation range 3.2-19.5%) while DR of invasive cancers was 5.3/1,000 (range 3.8-7.4/1,000) and DR of ductal carcinoma in situ (DCIS) was 1.3/1,000 (range 0.7-2.7/1,000). For subsequent screening, the adjusted EU-pooled PR was 3.6% (range 1.4-8.4%), the DR was 4.0/1,000 (range 2.2-5.8/1,000) and 0.8/1,000 (range 0.5-1.3/1,000) for invasive and DCIS, respectively. Adjusted performance indicators showed remarkable heterogeneity, likely due to different background breast cancer risk and awareness between target populations, and also different screening protocols and organisation. Periodic reporting of the screening indicators permits comparison and evaluation of the screening activities between and within countries aiming to improve the quality and the outcomes of screening programmes. Cancer Screening Registries would be a milestone in this direction and EU Screening Reports provide a fundamental contribution to building them.

Baseline findings and safety of infrequent vs. frequent screening of human papillomavirus vaccinated women.

Less frequent cervical cancer screening in human papillomavirus (HPV) vaccinated birth cohorts could produce considerable savings without increasing cervical cancer incidence and loss of life-years. We report here the baseline findings and interim results of safety and accuracy of infrequent screening among HPV16/18 vaccinated females. The entire 1992-1994 birth-cohorts (30,139 females) were invited to a community-randomized HPV16/18-vaccination trial. A total of 9,482 female trial participants received HPV16/18-vaccination in 2007-2009 at age of 13-15. At age 22, 4,273 (45%) of these females consented to attend a randomized trial on frequent (ages 22/25/28; Arm 1: 2,073 females) vs. infrequent screening (age 28; Arm 2: 2,200 females) in 2014-2017. Females (1,329), who had got HPV16/18 vaccination at age 18 comprised the safety Arm 3. Baseline prevalence and incidence of HPV16/18 and other high-risk HPV types were: 0.5% (53/1,000 follow-up years, 104 ) and 25% (2,530/104 ) in the frequently screened Arm 1; 0.2% (23/104 ) and 24% (2,413/104 ) in the infrequently screened Arm 2; and 3.1% (304/104 ) and 23% (2,284/104 ) in the safety Arm 3. Corresponding prevalence of HSIL/ASC-H and of any abnormal cytological findings were: 0.3 and 4.2% (Arm 1), 0.4 and 5.3% (Arm 2) and 0.3 and 4.7% (Arm 3). Equally rare HSIL/CIN3 findings in the infrequently screened safety Arm A3 (0.4%) and in the frequently screened Arm 1 (0.4%) indicate no safety concerns on infrequent screening despite the up to 10 times higher HPV16/18 baseline prevalence and incidence in the former.

Extension of the viral ecology in humans using viral profile hidden Markov models.

When human samples are sequenced, many assembled contigs are "unknown", as conventional alignments find no similarity to known sequences. Hidden Markov models (HMM) exploit the positions of specific nucleotides in protein-encoding codons in various microbes. The algorithm HMMER3 implements HMM using a reference set of sequences encoding viral proteins, "vFam". We used HMMER3 analysis of "unknown" human sample-derived sequences and identified 510 contigs distantly related to viruses (Anelloviridae (n = 1), Baculoviridae (n = 34), Circoviridae (n = 35), Caulimoviridae (n = 3), Closteroviridae (n = 5), Geminiviridae (n = 21), Herpesviridae (n = 10), Iridoviridae (n = 12), Marseillevirus (n = 26), Mimiviridae (n = 80), Phycodnaviridae (n = 165), Poxviridae (n = 23), Retroviridae (n = 6) and 89 contigs related to described viruses not yet assigned to any taxonomic family). In summary, we find that analysis using the HMMER3 algorithm and the "vFam" database greatly extended the detection of viruses in biospecimens from humans.

Viruses in cancers among the immunosuppressed.

Most cancer forms known to be caused by viruses are increased among the immunosuppressed, but several cancer forms without established viral etiology are also increased, notably nonmelanoma skin carcinoma (NMSC). We followed all 13,429 solid organ transplantation patients in Sweden for cancer occurrence after transplantation. We requested these tumor specimens and sequenced the first 89 specimens received (62 NMSCs, 27 other cancers). The sequences were analyzed for viruses based on two bioinformatics algorithms (paracel-blast (sensitive for detection of known viruses) and hidden Markov model (HMM; sensitive for distantly related viruses)). Among the 62 NMSCs, the virus family detected in the largest proportion of specimens was Mimiviridae (9/62 NMSCs). The majority of the virus-related reads belonged to Papillomaviridae. The HMM analysis identified 86 additional previously not described viral contigs related to 11 virus families, with reads related to Mimiviridae being the most common (detected in 28/62 NMSCs) with the most prevalent contig (Mimivirus SE906, 1937 bp) detected in 17/62 NMSCs. Among the 27 other cancers, viral sequences were detected in only 5 specimens by blast analysis, compared to in all 27 specimens by HMM (Mimiviridae, Poxviridae, Phycodnaviridae and virus-related sequences yet unclassified to any family). 99% of the virus reads belonged to a single previously not described sequence (Mimivirus SE996, 911 bp). A multitude of viruses is readily detectable in specimens with cancers occurring among the immunosuppressed, with sequences related to Mimiviridae being the most prevalent. Further research would be needed to elucidate the biological significance of the viruses.

Randomised healthcare policy evaluation of organised primary human papillomavirus screening of women aged 56-60.

OBJECTIVE: The aim of this research is to implement and reliably evaluate primary human papillomavirus (HPV) screening in an established and routinely running organised, large-scale population-based screening programme. PARTICIPANTS: Resident women in the Stockholm/Gotland region of Sweden, aged 56-60 years were randomised to either (1) screening with cervical cytology, with HPV test in triage of low-grade cytological abnormalities (old policy) or (2) screening with HPV testing, with cytology in triage of HPV positives (new policy). OUTCOME: The primary evaluation was the detection rate of cervical intraepithelial neoplasia grade 2 or worse (CIN2+). RESULTS: During January 2012-May 2014, the organised screening programme sent 42 752 blinded invitations with a prebooked appointment time to the women in the target age group. 7325 women attended in the HPV policy arm and 7438 women attended in the cytology arm. In the new policy, the population HPV prevalence was 5.5%, using an accredited HPV test (Cobas 4800). HPV16 prevalence was 1.0% (73/7325) and HPV18 prevalence was 0.3% (22/7325). In the HPV policy arm, 78/405 (19%) HPV-positive women were also cytology positive. There were 19 cases of CIN2+ in histopathology, all among women who were both HPV positive and cytology positive. The positive predictive value for CIN2+ in this group was 33.3% (19/57). In the cytology policy, 153 women were cytology positive and there were 18 cases of CIN2+ in histopathology. Both the total number of cervical biopsies and the number of cervical biopsies with benign histopathology were much lower in thepositive predictive value policy (49 benign, 87 total vs 105 benign, 132 total). CONCLUSION: Primary HPV screening had a similar detection rate for CIN2+ as cytology-based screening, already before follow-up of HPV-positive, cytology-negative women with new HPV test and referral of women with persistence. TRIAL REGISTRATION NUMBER: NCT01511328.

Registry-based assessment of the status of cervical screening in Sweden.

OBJECTIVES: Comprehensive nationwide monitoring and evaluation of screening through registry-based review of key indicators is necessary for programme optimization, especially as new tests and strategies are introduced. We aimed to investigate and report on the use of these key indicators in the Swedish programme. SETTING AND METHODS: Organized population-based cervical screening targeting women aged 23-50 and 51-60 every three and five years, respectively, is regionally implemented in Sweden. All cytological and histopathological test results and invitations are exported to the National Cervical Screening Registry. We describe the methods to obtain registry-based quality indicators by age, region, and calendar period. RESULTS: In 2013, there were 633,592 cervical smears in Sweden, of which 69% were organized smears resulting from an invitation. Screening test coverage for women aged 23-60 was 80% and similar for the previous decade, but varied greatly between and within counties over-time. Among women aged 23-25, test coverage increased dramatically during the previous six years, reaching 87% in 2013. The proportion of women with cytological high-grade cervical lesions found in cytology that had been followed-up with biopsy within one year was 97%. Major variations in cervical cancer incidence between counties were observed. CONCLUSIONS: Registry-based analyses of key quality indicators provided the basis for prioritizing improvements of the organized cervical screening programme.

Laboratory audit as part of the quality assessment of a primary HPV-screening program.

BACKGROUND: As primary HPV screening programs are rolled out, methods are needed for routine quality assurance of HPV laboratory analyzes. OBJECTIVE: To explore the use of similar design for audit as currently used in cytology-based screening, to estimate the clinical sensitivity to identify women at risk for CIN 3 or worse (CIN3+). STUDY DESIGN: Population-based cohort study conducted within the cervical screening program in Stockholm, Sweden, in 2011-2012. All women with histopathologically confirmed CIN3+ in the following two years were identified by registry analysis. Primary HPV and cytology screening results were collected. For women who had not been HPV tested, biobanked cytology samples were HPV-tested. If the original HPV result had been negative, the sample and subsequent biopsies were analyzed with broad HPV typing (general primer PCR and Luminex). RESULTS: 154 women had a biobanked prediagnostic cytology sample taken up to 2 years before a histopathologically confirmed CIN3+. The high-risk HPV-positivity was 97% (148/154 women), whereas 143/154 (94%) women had had a cytological abnormality. Among the six HPV-negative samples, one sample was HPV 33 positive in repeat testing whereas the other five cases were HPV-negative also on repeat testing, but HPV-positive in the subsequent tumor tissue. CONCLUSIONS: A sensitivity of the HPV test that is higher than the sensitivity of cytology suggests adequate quality of the testing. Regular audits of clinical sensitivity, similar to those of cytology-based screening, should be used also in HPV-based screening programs, in order to continuously monitor the performance of the analyzes.

Human Papillomavirus Vaccination of Boys and Extended Catch-up Vaccination: Effects on the Resilience of Programs.

BACKGROUND: Decreasing human papillomavirus (HPV) vaccine prices makes scaling up of vaccination programs attractive for countries that initially targeted 1 or a few birth cohorts of girls and/or achieved low coverage. This article aims to compare the impact of alternative HPV vaccination strategies, using data from Sweden, a high-income country that has experienced vaccine price changes. METHODS: Using an HPV transmission model, we compared the existing vaccination program to alternatives, accounting for a 1-time catch-up vaccination of 22-26-year-old women, with or without routine vaccination of school-age boys, and for a 1-time catch-up vaccination of males aged 13-26 years. We also assessed the resilience of vaccination alternatives to coverage reduction. RESULTS: On the basis of an HPV16/18 prevalence of 12% before the HPV vaccine era, extended catch-up vaccination for females and males yielded relative reductions in the HPV prevalence of 49.4% and 55.6%, respectively, during the first 10 years after the start of each vaccination strategy, whereas the existing program yielded a relative reduction of 38.6% during the same period. The increased prevalence reduction due to catch-up vaccination continued for about 30 years. As compared to female-only routine and extended catch-up vaccination, routine vaccination of males with or without catch-up was, respectively, 12.6-fold and 7.2-fold more resilient to coverage reduction. CONCLUSIONS: Vaccination strategies based on catch-up vaccination of females and males are effective for accelerating HPV prevalence reduction. Inclusion of routine male vaccination improves the resilience of vaccination programs.

Cervical cancer screening in Europe: Quality assurance and organisation of programmes.

BACKGROUND: Cervical screening programmes have reduced cervical cancer incidence and mortality but the level of success is highly variable between countries. Organisation of programmes is essential for equity and cost-effectiveness. However, there are differences in effectiveness, also among organised programmes. In order to identify the key organisational components that determine effectiveness, we performed a Europe-wide survey on the current status of organisation and organised quality assurance (QA) measures in cervical cancer prevention programmes, as well as organisation-associated costs. METHODS: A comprehensive questionnaire was developed through systematic review of literature and existing guidelines. The survey was sent to programme organisers, Ministries of Health and experts in 34 European Union (EU) and European Free Trade Agreement (EFTA) countries. Detailed aspects of programme organisation, quality assurance, monitoring, evaluation and corresponding line-item costs were recorded. Documentation of programme guidelines, protocols and publications was requested. RESULTS: Twenty-nine of 34 countries responded. The results showed that organised efforts for QA, monitoring and evaluation were carried out to a differing extent and were not standardised, making it difficult to compare the cost-effectiveness of organisation and QA strategies. Most countries found it hard to estimate the costs associated with launching and operating the organised programme. CONCLUSIONS: To our knowledge, this is the first questionnaire to request detailed information on the actual organisation and QA of programmes. The results of this survey can be used as a basis for further development of standardised guidelines on organisation and QA of cervical cancer screening programmes in Europe.

Organization and quality of HPV vaccination programs in Europe.

BACKGROUND: HPV vaccination is underway in most European countries, but there are limited efforts toward optimization and standardization of organization, monitoring and evaluation. Our Europe-wide survey sought to identify how programs are currently organized, the costs associated with the organizing and ensuring quality of the program and how quality and effectiveness measurements are carried out. METHODS: A comprehensive questionnaire was developed through systematic literature review and the European guidelines for quality assurance in cervical screening. The survey was piloted in a sub-set of countries and then sent to program organizers, Ministries of Health, and key experts in 34 EU and EFTA countries (including countries within the UK). Detailed information on program organization and target population, monitoring and evaluation (including indicators used for evaluating the impact of vaccination), and associated costs were collected. In addition, documentation of program guidelines, protocols, and publications were requested. RESULTS: Of the 34 countries contacted, 27 responded. The majority of countries had some level of vaccination activity, with approximately half of the countries reporting an organized vaccination program. Centralized vaccine registries were in place in the majority of countries with an organized program, allowing for monitoring of key indicators at the national level. Costs of organization and monitoring were difficult to estimate and varied significantly, as some countries were able to use existing infrastructures while others had to create new systems, incurring greater costs. CONCLUSIONS: The organization and quality of HPV vaccination programs differ across countries and, in some instances, even across regions within the same country. The monitoring being performed varies across programs with regard to level of detail but engagement in the survey from the participating countries demonstrates that there is strong interest in reflecting on and improving program performance. This survey could serve as a basis for strengthening surveillance of HPV vaccination programs.

The process of moving from a regionally based cervical cytology biobank to a national infrastructure.

This article addresses the important issue of the standardization of the biobank process. It reports on i) the implementation of standard operating procedures for the processing of liquid-based cervical cells, ii) the standardization of storage conditions, and iii) the ultimate establishment of nationwide standardized biorepositories for cervical specimens. Given the differences in the infrastructure and healthcare systems of various county councils in Sweden, these efforts were designed to develop standardized methods of biobanking across the nation. The standardization of cervical sample processing and biobanking is an important and widely acknowledged issue. Efforts to address these concerns will facilitate better patient care and improve research based on retrospective and prospective collections of patient samples and cohorts. The successful nationalization of the Cervical Cytology Biobank in Sweden is based on three vital issues: i) the flexibility of the system to adapt to other regional systems, ii) the development of the system based on national collaboration between the university and the county councils, and iii) stable governmental financing by the provider, the Biobanking and Molecular Resource Infrastructure of Sweden (BBMRI.se). We will share our experiences with biorepository communities to promote understanding of and advances in opportunities to establish a nationalized biobank which covers the healthcare of the entire nation.

Translational cancer research: balancing prevention and treatment to combat cancer globally.

Cancer research is drawing on the human genome project to develop new molecular-targeted treatments. This is an exciting but insufficient response to the growing, global burden of cancer, particularly as the projected increase in new cases in the coming decades is increasingly falling on developing countries. The world is not able to treat its way out of the cancer problem. However, the mechanistic insights from basic science can be harnessed to better understand cancer causes and prevention, thus underpinning a complementary public health approach to cancer control. This manuscript focuses on how new knowledge about the molecular and cellular basis of cancer, and the associated high-throughput laboratory technologies for studying those pathways, can be applied to population-based epidemiological studies, particularly in the context of large prospective cohorts with associated biobanks to provide an evidence base for cancer prevention. This integrated approach should allow a more rapid and informed translation of the research into educational and policy interventions aimed at risk reduction across a population.

Association of varying number of doses of quadrivalent human papillomavirus vaccine with incidence of condyloma.

IMPORTANCE: Determining vaccine dose-level protection is essential to minimize program costs and increase mass vaccination program feasibility. Currently, a 3-dose vaccination schedule is recommended for both the quadrivalent and bivalent human papillomavirus (HPV) vaccines. Although the primary goal of HPV vaccination programs is to prevent cervical cancer, condyloma related to HPV types 6 and 11 is also prevented with the quadrivalent vaccine and represents the earliest measurable preventable disease outcome for the HPV vaccine. OBJECTIVE: To examine the association between quadrivalent HPV vaccination and first occurrence of condyloma in relation to vaccine dose in a population-based setting. DESIGN, SETTING, AND PARTICIPANTS: An open cohort of all females aged 10 to 24 years living in Sweden (n = 1,045,165) was followed up between 2006 and 2010 for HPV vaccination and first occurrence of condyloma using the Swedish nationwide population-based health data registers. MAIN OUTCOMES AND MEASURES: Incidence rate ratios (IRRs) and incidence rate differences (IRDs) of condyloma were estimated using Poisson regression with vaccine dose as a time-dependent exposure, adjusting for attained age and parental education, and stratified on age at first vaccination. To account for prevalent infections, models included a buffer period of delayed case counting. RESULTS: A total of 20,383 incident cases of condyloma were identified during follow-up, including 322 cases after receipt of at least 1 dose of the vaccine. For individuals aged 10 to 16 years at first vaccination, receipt of 3 doses was associated with an IRR of 0.18 (95% CI, 0.15-0.22) for condyloma, whereas receipt of 2 doses was associated with an IRR of 0.29 (95% CI, 0.21-0.40). One dose was associated with an IRR of 0.31 (95% CI, 0.20-0.49), which corresponds to an IRD of 384 cases (95% CI, 305-464) per 100,000 person-years, compared with no vaccination. The corresponding IRDs for 2 doses were 400 cases (95% CI, 346-454) and for 3 doses, 459 cases (95% CI, 437-482). The number of prevented cases between 3 and 2 doses was 59 (95% CI, 2-117) per 100,000 person-years. CONCLUSIONS AND RELEVANCE: Although maximum reduction in condyloma risk was seen after receipt of 3 doses of quadrivalent HPV vaccine, receipt of 2 vaccine doses was also associated with a considerable reduction in condyloma risk. The implications of these findings for the relationship between number of vaccine doses and cervical cancer risk require further investigation.

Upscaling human papillomavirus vaccination in high-income countries: impact assessment based on transmission model.

BACKGROUND: The decrease in human papillomavirus (HPV) vaccine prices may allow upscale already started vaccination programmes but the advantages of different options are unclear. METHODS: Using a mathematical model of HPV16 and 18 transmission and data on vaccination coverage from Italy, we compared 3 options to upscale an already started programme targeting 11-year old girls (coverage 65%): a) coverage improvement (from 65% to 90%); b) addition of 11-year-old boys (coverage 65%); or c) 1-year catch-up of older girls (coverage 50%). RESULTS: The reduction of cervical HPV16/18 infection as compared to no vaccination (i.e. effectiveness against HPV16/18) increased from 76% to 98% with coverage improvement in girls and to 90% with the addition of boys. With higher coverage in girls, HPV16/18 infection cumulative probability by age 35 decreased from 25% to 8% with a 38% increase in vaccine number. The addition of boys decreased the cumulative probability to 18% with a 100% increase in the number of vaccinees. For any coverage in girls, the number of vaccinees to prevent 1 woman from being infected by HPV16/18 by age 35 was 1.5, whereas it was 2.7 for the addition of boys. Catch-up of older girls only moved forward the vaccination effectiveness by 2-5 years. CONCLUSIONS: Increasing vaccination coverage among girls is the most effective option for decreasing HPV16/18. If not achievable, vaccinating boys is justifiable if vaccine cost has at least halved, because this option would almost double the number of vaccinees.