Long-term follow-up of cervical cancer incidence after normal cytological findings.

An increase in cervical cancer incidence in Sweden from 2014 to 2015 has been attributed to an increase in false-negative cytological findings before cancer diagnoses. Years later, we performed a long-term follow-up to investigate whether the problem persisted. At each calendar year from 2016 to 2020, we identified women with prior normal cervical screening results through linkage to the Swedish National Cervical Screening Registry. We reported their incidence rates (IRs) of invasive cervical cancer in consecutive years and compared the IRs over time. For the years 2016 to 2020, there was no overall change in cervical cancer incidence after two normal cytology in the last two screening intervals. However, there was a further 62% increase among women 50 to 60 years of age with normal cytology in the past two screening intervals. The incidence rate of cervical cancer was high among nonscreened women and low among HPV-screened women with negative results, with no trends over time. Our results imply that the previously reported decrease in sensitivity of cervical cytology is persisting. Although primary cytology screening is no longer used, cytology is used in triaging among HPV-positive women. Our findings suggest that improved triaging is needed, for example, improved quality assurance and/or use of alternative triage tests.

Scientific approaches toward improving cervical cancer elimination strategies.

At the 2023 EUROGIN workshop scientific basis for strategies to accelerate the elimination of cervical cancer and its causative agent, human papillomavirus (HPV) were reviewed. Although some countries have reached key performance indicators toward elimination (>90% of girls HPV vaccinated and >70% of women HPV screened), most are yet to reach these targets, implying a need for improved strategies. Gender-neutral vaccination, even with moderate vaccination coverage was highlighted as a strategy to achieve elimination more rapidly. It is more resilient against major disturbances in vaccination delivery, such as what happened during the coronavirus pandemic. Further, an analysis of ethical/legal issues indicated that female-restricted vaccination is problematic. Extended catch-up of vaccination with concomitant screening, and outreach to vulnerable groups were highlighted. Although birth cohorts with high coverage of HPV vaccination at school are protected against HPV, and HPVs have a very low reproductive rate in women above age 35, adult women below age 30 have inadequate direct protection. In addition to herd protection from gender-neutral vaccination, this group can be protected by offering concomitant catch-up HPV vaccination and HPV screening. Furthermore, hepatitis B vaccination experiences indicate that elimination cannot be achieved without prioritizing vulnerable/migrant populations. The long-lasting durability of vaccination-induced antibody responses suggests prolonged protection with HPV vaccines when adequately administrated. Finally, cost-effectiveness modelling suggests that high-coverage HPV vaccination in multiple population segments will be resource-saving due to reduced need for screening. In summary, the workshop found that strategically optimal deployment of vaccination will accelerate elimination of HPV and cervical cancer.

Low methylation marker levels among human papillomavirus-vaccinated women with cervical high-grade squamous intraepithelial lesions.

Cervical cancer screening programs, including triage tests, need redesigning as human papillomavirus (HPV)-vaccinated women are entering the programs. Methylation markers offer a potential solution to reduce false-positive rates by identifying clinically relevant cervical lesions with progressive potential. In a nested case-control study, 9242 women who received the three-dose HPV16/18-vaccine at ages 12-15 or 18 in a community-randomized trial were included. Subsequently, they were re-randomized for either frequent or infrequent cervical cancer screening trials. Over a 15-year post-vaccination follow-up until 2022, 17 high-grade squamous intraepithelial lesion (HSIL) and 15 low-grade (LSIL) cases were identified at the 25-year screening round, alongside 371 age and community-matched HPV16/18-vaccinated controls. Methylation analyses were performed on cervical samples collected at age 25, preceding histologically confirmed LSIL or HSIL diagnoses. DNA methylation of viral (HPV16/18/31/33) and host-cell genes (EPB41L3, FAM19A4, and miR124-2) was measured, along with HPV-genotyping. No HPV16/18 HSIL cases were observed. The predominant HPV-genotypes were HPV52 (29.4%), HPV59/HPV51/HPV58 (each 23.5%), and HPV33 (17.7%). Methylation levels were generally low, with no significant differences in mean methylation levels of viral or host-cell genes between the LSIL/HSIL and controls. However, a significant difference in methylation levels was found between HSIL cases and controls when considering a combination of viral genes and EPB41L3 (p value = .0001). HPV-vaccinated women with HSIL had HPV infections with uncommon HPV types that very rarely cause cancer and displayed low methylation levels. Further investigation is warranted to understand the likely regressive nature of HSIL among HPV-vaccinated women and its implications for management.

Divergent effects of switching from cytology to HPV-based screening in the Nordic countries.

BACKGROUND: Cervical cytology has been the primary method of cervical cancer screening for decades. Tests that detect viral HPV are shown in several randomized trials to provide better protection against cancer compared with cytology. HPV-based screening has been implemented alongside cytology in the Nordic countries for several years. The aim of this study was to compare cytology and HPV-based screening in the colposcopy referrals and detection rates of cervical lesions. METHODS: Individual-level screening data from Finland, Iceland, Norway and Sweden were harmonized and aggregated locally. We utilized data for tests taken during years 2015-17 and biopsies taken during years 2015-19 to allow 24 months of follow-up. Age-standardized estimates and age-adjusted risk ratios for six different outcomes of screening management were calculated. RESULTS: The age-standardized colposcopy rates were higher in HPV-based testing compared with cytology in Finland (3.5% vs. 0.9%) and Norway (6.0% vs. 4.1%) but lower in Sweden (3.7% vs. 4.9%). The relative detection rate of cervical intraepithelial neoplasia grade 2 and above in HPV-based testing compared with cytology was highest in Finland (RR 2.37, 95% CI 2.13-2.63) and Norway (RR 1.66, 95% CI 1.57-1.72) while in Sweden the difference was not statistically significant (RR 0.98, 95% CI 0.95-1.00). CONCLUSIONS: The effects of implementing HPV screening varied by country as different screening algorithms were implemented. HPV-based screening increases colposcopy rates mainly through referrals from increased repeat testing and detection rate is therefore significantly higher compared with cytology. Monitoring of these indicators in subsequent rounds of HPV-based screening remains essential.

HPV-induced host epigenetic reprogramming is lost upon progression to high-grade cervical intraepithelial neoplasia.

The impact of a pathogen on host disease can only be studied in samples covering the entire spectrum of pathogenesis. Persistent oncogenic human papilloma virus (HPV) infection is the most common cause for cervical cancer. Here, we investigate HPV-induced host epigenome-wide changes prior to development of cytological abnormalities. Using cervical sample methylation array data from disease-free women with or without an oncogenic HPV infection, we develop the WID (Women's cancer risk identification)-HPV, a signature reflective of changes in the healthy host epigenome related to high-risk HPV strains (AUC = 0.78, 95% CI: 0.72-0.85, in nondiseased women). Looking at HPV-associated changes across disease development, HPV-infected women with minor cytological alterations (cervical intraepithelial neoplasia grade 1/2, CIN1/2), but surprisingly not those with precancerous changes or invasive cervical cancer (CIN3+), show an increased WID-HPV index, indicating the WID-HPV may reflect a successful viral clearance response absent in progression to cancer. Further investigation revealed the WID-HPV is positively associated with apoptosis (ρ = 0.48; P < .001) and negatively associated with epigenetic replicative age (ρ = -0.43; P < .001). Taken together, our data suggest the WID-HPV captures a clearance response associated with apoptosis of HPV-infected cells. This response may be dampened or lost with increased underlying replicative age of infected cells, resulting in progression to cancer.

Assessing the risk of cervical neoplasia in the post-HPV vaccination era.

This review is based on the recent EUROGIN scientific session: "Assessing risk of cervical cancer in the post-vaccination era," which addressed the demands of cervical intraepithelial neoplasia (CIN)/squamous intraepithelial lesion (SIL) triage now that the prevalence of vaccine-targeted oncogenic high-risk (hr) human papillomaviruses (HPVs) is decreasing. Change in the prevalence distribution of oncogenic HPV types that follows national HPV vaccination programs is setting the stage for loss of positive predictive value of conventional but possibly also new triage modalities. Understanding the contribution of the latter, most notably hypermethylation of cellular and viral genes in a new setting where most oncogenic HPV types are no longer present, requires studies on their performance in vaccinated women with CIN/SIL that are associated with nonvaccine HPV types. Lessons learned from this research may highlight the potential of cervical cells for risk prediction of all women's cancers.

The WID-EC test for the detection and risk prediction of endometrial cancer.

The incidence of endometrial cancer is rising. Measures to identify women at risk and to detect endometrial cancer earlier are required to reduce the morbidity triggered by the aggressive treatment required for advanced endometrial cancer. We developed the WID-EC (Women's cancer risk IDentification-Endometrial Cancer) test, which is based on DNA methylation at 500 CpG sites, in a discovery set of cervical liquid-based cytology samples from 1086 women with and without an endometrial cancer (217 cancer cases and 869 healthy controls) with a worse prognosis (grade 3 or ≥stage IB). We validated the WID-EC test in an independent external validation set of 64 endometrial cancer cases and 225 controls. We further validated the test in 150 healthy women (prospective set) who provided a cervical sample as part of the routine Swedish cervical screening programme, 54 of whom developed endometrial cancer within 3 years of sample collection. The WID-EC test identified women with endometrial cancer with a receiver operator characteristic area under the curve (AUC) of 0.92 (95% CI: 0.88-0.97) in the external set and of 0.82 (95% CI: 0.74-0.89) in the prospective validation set. Using an optimal cutoff, cancer cases were detected with a sensitivity of 86% and a specificity of 90% in the external validation set, and a sensitivity and specificity of 52% and 98% respectively in the prospective validation set. The WID-EC test can identify women with or at risk of endometrial cancer.

Impact of cervical screening by human papillomavirus genotype: Population-based estimations.

BACKGROUND: Cervical screening programs use testing for human papillomavirus (HPV) genotypes. Different HPV types differ greatly in prevalence and oncogenicity. We estimated the impact of cervical screening and follow-up for each HPV type. METHODS AND FINDINGS: For each type of HPV, we calculated the number of women needed to screen (NNS) and number of women needing follow-up (NNF) to detect or prevent one cervical cancer case, using the following individual level input data (i) screening and cancer data for all women aged 25 to 80 years, resident in Sweden during 2004 to 2011 (N = 3,568,938); (ii) HPV type-specific prevalences and screening histories among women with cervical cancer in Sweden in 2002 to 2011(N = 4,254); (iii) HPV 16/18/other HPV prevalences in the population-based HPV screening program (N = 656,607); and (iv) exact HPV genotyping in a population-based cohort (n = 12,527). Historical screening attendance was associated with a 72% reduction of cervical cancer incidence caused by HPV16 (71.6%, 95% confidence interval (CI) [69.1%, 73.9%]) and a 54% reduction of cancer caused by HPV18 (53.8%, 95% CI [40.6%, 63.1%]). One case of HPV16-caused cervical cancer could be prevented for every 5,527 women attending screening (number needed to screen, NNS). Prevention of one case of HPV16-caused cervical cancer required follow-up of 147 HPV16-positive women (number needed to follow-up, NNF). The NNS and NNF were up to 40 to 500 times higher for HPV types commonly screened for with lower oncogenic potential (HPV35,39,51,56,59,66,68). For women below 30 years of age, NNS and NNF for HPV16 were 4,747 and 289, respectively, but >220,000 and >16,000 for HPV35,39,51,56,59,66,68. All estimates were either age-standarized or age-stratified. The primary limitation of our study is that NNS is dependent on the HPV prevalence that can differ between populations and over time. However, it can readily be recalculated in other settings and monitored when HPV type-specific prevalence changes. Other limitations include that in some age groups, there was little data and extrapolations had to be made. Finally, there were very few cervical cancer cases associated with certain HPV types in young age group. CONCLUSIONS: In this study, we observed that the impact of cervical cancer screening varies depending on the HPV type screened for. Estimating and monitoring the impact of screening by HPV type can facilitate the design of effective and efficient HPV-based cervical screening programs. TRIAL REGISTRATION: ClinicalTrials.gov with numbers NCT00479375, NCT01511328.

HPV Vaccination and the Risk of Invasive Cervical Cancer.

BACKGROUND: The efficacy and effectiveness of the quadrivalent human papillomavirus (HPV) vaccine in preventing high-grade cervical lesions have been shown. However, data to inform the relationship between quadrivalent HPV vaccination and the subsequent risk of invasive cervical cancer are lacking. METHODS: We used nationwide Swedish demographic and health registers to follow an open population of 1,672,983 girls and women who were 10 to 30 years of age from 2006 through 2017. We assessed the association between HPV vaccination and the risk of invasive cervical cancer, controlling for age at follow-up, calendar year, county of residence, and parental characteristics, including education, household income, mother's country of birth, and maternal disease history. RESULTS: During the study period, we evaluated girls and women for cervical cancer until their 31st birthday. Cervical cancer was diagnosed in 19 women who had received the quadrivalent HPV vaccine and in 538 women who had not received the vaccine. The cumulative incidence of cervical cancer was 47 cases per 100,000 persons among women who had been vaccinated and 94 cases per 100,000 persons among those who had not been vaccinated. After adjustment for age at follow-up, the incidence rate ratio for the comparison of the vaccinated population with the unvaccinated population was 0.51 (95% confidence interval [CI], 0.32 to 0.82). After additional adjustment for other covariates, the incidence rate ratio was 0.37 (95% CI, 0.21 to 0.57). After adjustment for all covariates, the incidence rate ratio was 0.12 (95% CI, 0.00 to 0.34) among women who had been vaccinated before the age of 17 years and 0.47 (95% CI, 0.27 to 0.75) among women who had been vaccinated at the age of 17 to 30 years. CONCLUSIONS: Among Swedish girls and women 10 to 30 years old, quadrivalent HPV vaccination was associated with a substantially reduced risk of invasive cervical cancer at the population level. (Funded by the Swedish Foundation for Strategic Research and others.).

The International Human Papillomavirus Reference Center: Standardization, collaboration, and quality assurance in HPV research and diagnostics.

The International Human Papillomavirus (HPV) Reference Center (IHRC) confirms and assigns type numbers to novel HPV types, maintains a reference clone repository, and issues international proficiency panels for HPV screening and genotyping. Furthermore, the Center coordinates the Global HPV Reference Laboratory Network that promotes collaboration and international exchange of experiences among national HPV reference laboratories, to further international standardization and quality assurance in the HPV field. The established HPV types (n = 225) belong to 5 different genera: alpha (n = 65), beta (n = 54), gamma (n = 102), mu (n = 3) and nu (n = 1). Since the last published IHRC overview in 2018, 6 novel types have been established, with 5/6 belonging to the gamma genus and 1/6 to beta genus. Also, 474 reference clones have been provided to 55 different research laboratories and the global proficiency program for HPV genotyping has seen an increasing proficiency (despite a decrease seen in 2019), from 68% proficiency in 2017 to 77.3% in 2022. The first proficiency study for HPV screening found an international proficiency of up to 77%. In summary, increasing complexity of the HPVs and demands on quality assurance in the era of cervical cancer elimination requires international efforts to support proficiency and recognized quality and order among HPV types.

Evaluation of co-testing with cytology and human papillomavirus testing in cervical screening.

Cervical screening is increasingly switching to human papillomavirus (HPV) testing. In many settings, the switch has involved one or several co-tests (testing using both cytology and HPV) in the screening guidelines, to ensure safety. When Sweden switched to HPV testing in 2015 the guidelines included a co-test at age 41. To evaluate the effect of co-testing, we identified all 208,701 women resident in Sweden who in 2019 were 40-42 years old and thus eligible for co-testing. All cervical samples, the results of the test and of the subsequent biopsies were identified in the Swedish National Cervical Screening Registry. Out of the 10,643 women with co-testing in screening, there were 197 women with a subsequent biopsy with high-grade cervical neoplasia or worse (CIN2+). Among these 197 women, 189 had a screening test positive for both HPV and cytology, 6 women were HPV+/Cyt- and 2 women were HPV-/Cyt+. There were 7115 women with a co-test outside of the screening program. Among these, 325 women had a CIN2+ in histopathology, 290 were double positive, 13 women were cyt+/HPV-, and 11 women each were HPV+/cyt- and HPV-/Cyt-. In summary, the additional yield of CIN2+ with co-testing was 2 cases per 10,643 women as compared with 195/10,643 CIN2+ cases detected with HPV screening alone. However, for cervical samples taken outside the screening program (e.g. taken on a clinical indication) there was an increased yield (314 CIN2+ cases detected with co-testing as compared to 301 cases with HPV screening).

Quality assurance in human papillomavirus testing for primary cervical screening.

The recommendation for cervical screening is that it should be based on human papillomavirus (HPV) molecular testing. For all screening programs, attention to quality assurance is required to fully realize the benefits. Internationally recognized quality assurance recommendations for HPV-based screening are needed that are ideally applicable for a variety of settings, including in low- and middle-income countries. We summarize the main points of quality assurance for HPV screening, with a focus on the selection, implementation, and use of an HPV screening test, quality assurance systems (including internal quality control and external quality assessment), and staff competence. While we recognize that it might not be possible to fulfill all points in all settings, an awareness of the issues is essential.

Head-to-Head Comparison of Bi- and Nonavalent Human Papillomavirus Vaccine-Induced Antibody Responses.

For head-to-head comparison of human papillomavirus (HPV) antibody levels induced by different vaccines, 25-year-old vaccine-naive women were given either the bivalent (n = 188) or the nonavalent HPV vaccine (n = 184). Six months after vaccination antibodies against pseudovirions from 17 different HPV types (HPV6/11/16/18/31/33/35/39/45/51/52/56/58/59/66/68/73) were measured. Antibodies against HPV16/18 were higher after bivalent HPV vaccination (mean international units [IU] 1140.1 and 170.5 for HPV16 and 18, respectively) than after nonavalent vaccination (265.1 and 22.3 IUs, respectively). The bivalent vaccine commonly induced antibodies against the nonvaccine HPV types 31/33/35/45 or 58. The nonavalent vaccine induced higher antibodies against HPV6/11/31/33/45/52/58 and 35.

Human papillomavirus self-sampling with mRNA testing benefits routine screening.

High risk human papillomavirus (hrHPV) based screening provides the possibility of vaginal self-sampling as a tool to increase screening attendance. In order to evaluate the impact and feasibility of opt-in self-sampling in the Finnish setting, we invited a randomized population of 5350 women not attending screening after age group invitation or after reminder, to attend HPV self-sampling-based screening in the autumn of 2018 in Helsinki. Out of those, 1282 (24.0%) expressed their interest and ordered the sampling package. Eventually 787 women (14.7% of the total invited population) took part in screening, 770 women by providing a vaginal sample within 2 months from invitation and 17 by providing a pap smear in the laboratory. Self-taken samples were collected in Aptima Multitest vials and tested using the Aptima HPV mRNA assay. A high proportion, 158/770 (20.5%) of the samples were positive in the Aptima HPV assay. One hundred and forty-one samples were further submitted to Aptima HPV Genotyping and extended genotyping by a Luminex based assay. Of those, 23 samples (16.3%) were HPV 16 positive and 7 (5.0%) were positive for HPV 18/45; extended genotyping revealed multiple high-risk and low-risk HPV genotypes. At follow-up seven cases of high-grade squamous intraepithelial lesion (HSIL) were diagnosed, which represents 4.4% of HPV positive women and 0.9% of screened women, whereas the rate was 0.5% in routine screening. Our findings suggest that self-sampling with HPV mRNA testing is a feasible approach to improve screening efficacy in a high-risk population among original nonattendees.

Atypical glandular cells and development of cervical cancer: Population-based cohort study.

The effect of cervical screening on cervical adenocarcinoma has been variable, possibly because the risk associated with the precursor atypical glandular cells (AGC) is not well known. A cohort of all 885 women in the capital region of Sweden with AGC, a concomitant human papillomavirus (HPV) analysis, and a histopathology was followed until 2019. Cumulative incidence proportions of cervical intraepithelial lesion grade 3 or worse (CIN3+) by HPV type was determined by 1-Kaplan-Meier estimates. Hazard ratios (HR) for CIN3+ or for invasive cancer were estimated with Cox regression. After 2 years of follow-up, the cumulative incidence proportions of CIN3+ were 80% (95% confidence interval [CI]: 74-86%), 58% (95% CI: 50-60%) and 10% (95% CI: 5-18%) among HPV16/18 positive, "other HPV" positive and HPV-negative women, respectively. Among the 300 women with HPV16/18 positive AGC, 217 developed CIN3+ of which 35 were invasive cervical cancer. The 2-year cumulative invasive cancer risk for HPV16/18 positive AGC was 17% (95% CI: 12-24%). Primary HPV-screening had a similar yield of CIN3+ as cytology screening, albeit HPV-negative AGC is by design not detected by HPV screening. Among 241 women with HPV-negative AGC, 11 developed CIN3+ mostly after clinically indicated samples. We found no significant risk differences depending on age or sampling indication. The low CIN3+ risk after HPV-negative AGC implies safety of primary HPV screening. The high risk of invasive cervical cancer after HPV16/18 positive AGC implies that management of this finding is a priority in cervical screening.

Shared environment and colorectal cancer: A Nordic pedigree registry-based cohort study.

Risk of colorectal cancer (CRC) increases in relatives of patients with CRC. The extent to which this is attributable to genetic predisposition or shared environment is unclear. We explored this question using nationwide cohorts from Denmark, Finland and Sweden. From 1977 to 2013, we identified 359 879 individuals with a CRC diagnosis and 2 258 870 of their relatives who we followed for CRC incidence. We calculated standardized incidence ratios (SIR) and 95% confidence intervals (CI) for CRC in individuals with an affected relative. We used nationwide household and pedigree data along with national SIR estimates to calculate risk ratios (RR) for the contribution of shared household environment, childhood environment and genetic relationship to CRC risk in those with an affected relative. SIR of CRC was increased for individuals with an affected relative, across all countries and ages. For those with an affected parent, the SIR was 1.65 (95% CI: 1.61-1.69), 1.98 (95% CI: 1.87-2.09), for those with an affected sibling and 2.14 (95% CI: 1.84-2.49) for those with an affected halfsibling. In those <65 years old, shared childhood (RR: 1.41, 95% CI: 1.26-1.57) and household (RR: 2.08, 95% CI: 1.25-3.46) environments were significantly greater contributors to familial risk of CRC than genetics (RR: 0.88, 95% CI: 0.53-1.46). This large-scale Nordic population-based study of excess risk of CRC among relatives of those with CRC addresses the difficult disentangling of shared environment from genetic predisposition in the heritability of CRC. We found shared environment to be the most important contributor to CRC risk.

Overtreatment rate after immediate local excision of suspected cervical intraepithelial neoplasia: A prospective cohort study.

OBJECTIVE: The gold standard of cervical intraepithelial neoplasia (CIN) treatment is large loop excision of the transformation zone (LLETZ) after histopathological diagnosis from punch biopsies. In addition, treatment may be appropriate at initial colposcopy. Our objective was to study the applicability of immediate treatment strategy according to clinical parameters. METHODS: We conducted a prospective cohort study among patients referred to colposcopy at Helsinki University Hospital, Finland, between January 2014, and September 2018 (ISRCTN10933736). Patients treated with LLETZ, either after biopsies or immediately at initial colposcopy, were included. The main outcome measure was overtreatment (OT) rate defined as normal or low-grade histopathological findings in LLETZ specimen within both treatment groups. RESULTS: A total of 572 patients treated with LLETZ were included: 360 treated after biopsies and 212 treated immediately at initial colposcopy. When LLETZ was performed immediately after high-grade referral cytology and with colposcopic impression of high-grade disease, the overtreatment (OT) rate was 10.0% (95% CI 9.10 to 17.2), whereas when LLETZ was done after biopsy-confirmed high-grade lesions, the OT rate was 18.9% (95% CI 14.7 to 23.7), resulting in risk difference (RD) -8.91% (95% CI -16.0 to -1.82). Among HPV16/18 positive patients the OT rate was 8.22% (95% CI 3.08 to 17.0) for immediate treatment, resulting in RD of -10.7% (95% CI -18.3 to -3.04) compared to LLETZ after biopsies. CONCLUSIONS: Immediate LLETZ does not result in overtreatment when applied on selected cases, especially after high-grade referral cytology and when high-grade lesion is also colposcopically suspected.

Sustained Cross-reactive Antibody Responses After Human Papillomavirus Vaccinations: Up to 12 Years Follow-up in the Finnish Maternity Cohort.

BACKGROUND: Human papillomaviruses (HPV) cause several human cancers. Bivalent (Cervarix) and quadrivalent (qGardasil) HPV vaccines both contain virus-like particles of the major oncogenic HPV types 16 and 18, but also cross-protect against some nonvaccine types. However, data on long-term sustainability of the cross-reactive antibody responses to HPV vaccines are scarce. METHODS: Serum samples donated 7-12 years after immunization at age 16-17 years with bivalent (n = 730) or quadrivalent (n = 337) HPV vaccine were retrieved from the population-based Finnish Maternity Cohort biobank. Serum antibody levels against HPV types 6, 11, 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 68, and 73 were determined using multiplex pseudovirion binding assay. Antibody avidity was assessed using ammonium thiocyanate treatment. RESULTS: Seropositivity for HPV31, 33, 35, 45, 51, 52, 58, 59, 68, and 73 was increasingly common (P ≤ .001; χ 2 test for trend for each of these types) when women had high anti-HPV16 antibody levels. For 8 nonvaccine HPV types seropositivity was more common among recipients of bivalent than quadrivalent vaccine, in particular for HPV31, 35, 45, 51, 52, and 58 (P < .001). Antibody avidity was higher in the quadrivalent vaccine recipients for HPV6, 11, and two of the nonvaccine types, but lower for HPV16 and 18 (P < .001). CONCLUSIONS: Both vaccines elicit cross-reactive antibodies detectable even 12 years after vaccination. Cross-reactive seropositivity is more common in women with high anti-HPV16 antibody response and in the bivalent vaccine recipients.

High Amounts of SARS-CoV-2 Precede Sickness Among Asymptomatic Health Care Workers.

BACKGROUND: Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) positivity among asymptomatic subjects reflects past or future disease may be difficult to ascertain. METHODS: We tested 9449 employees at Karolinska University Hospital, Stockholm, Sweden for SARS-CoV-2 RNA and antibodies, linked the results to sick leave records, and determined associations with past or future sick leave using multinomial logistic regression. RESULTS: Subjects with high amounts of SARS-CoV-2 virus, indicated by polymerase chain reaction (PCR) cycle threshold (Ct) value, had the highest risk for sick leave in the 2 weeks after testing (odds ratio [OR], 11.97; 95% confidence interval [CI], 6.29-22.80) whereas subjects with low amounts of virus had the highest risk for sick leave in the 3 weeks before testing (OR, 6.31; 95% CI, 4.38-9.08). Only 2.5% of employees were SARS-CoV-2 positive while 10.5% were positive by serology and 1.2% were positive in both tests. Serology-positive subjects were not at excess risk for future sick leave (OR, 1.06; 95% CI, .71-1.57). CONCLUSIONS: High amounts of SARS-CoV-2 virus, as determined using PCR Ct values, was associated with development of sickness in the next few weeks. Results support the concept that PCR Ct may be informative when testing for SARS-CoV-2. Clinical Trials Registration. NCT04411576.

Estimating Total Excess Mortality During a Coronavirus Disease 2019 Outbreak in Stockholm, Sweden.

Total excess mortality peaked during a coronavirus disease 2019 (COVID-19) outbreak in Stockholm, but 25% of these deaths were not recognized as COVID-19 related nor occurred in hospitals. Estimate of total excess mortality may give a more comprehensive picture of the total disease burden during a COVID-19 outbreak, and may facilitate managing future outbreaks.