Monitoring Effect of Human Papillomavirus Vaccines in US Population, Emerging Infections Program, 2008-2012

Incidence and Types of Human Papillomavirus Infections in Adolescent Girls and Young Women Immunized With the Human Papillomavirus Vaccine

IMPORTANCE

Rates of human papillomavirus (HPV) infection have decreased since the introduction of HPV vaccines in populations with high vaccine uptake. Data are limited for adolescent and young adult populations in US metropolitan centers.

OBJECTIVE

To determine HPV infection rates in adolescent girls and young women aged 13 to 21 years in New York City following HPV vaccination.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study of type-specific cervical HPV detection was conducted at a large adolescent-specific integrated health center in New York City between October 2007 and September 2019. Participants included an open cohort of adolescent girls and young adult women who received the HPV vaccine (Gardasil; Merck & Co) over a 12-year period following HPV vaccination introduction. Data analysis was concluded September 2019.

EXPOSURES

Calendar date and time since receipt of first vaccine dose.

MAIN OUTCOMES AND MEASURES

Temporal associations in age-adjusted postvaccine HPV rates.

RESULTS

A total of 1453 participants, with a mean (SD) age at baseline of 18.2 (1.4) years, were included in the cohort (African American with no Hispanic ethnicity, 515 [35.4%] participants; African American with Hispanic ethnicity, 218 [15.0%] participants; Hispanic with no reported race, 637 [43.8%] participants). Approximately half (694 [47.8%] participants) were vaccinated prior to coitarche. Age-adjusted detection rates for quadrivalent vaccine types (HPV-6, HPV-11, HPV-16, and HPV-18) and related types (HPV-31, and HPV-45) decreased year over year, with the largest effect sizes observed among individuals who had been vaccinated before coitarche (adjusted odds ratio [aOR], 0.81; 95% CI, 0.67-0.98). By contrast, detection was higher year over year for nonvaccine high-risk cervical HPV types (aOR, 1.08; 95% CI, 1.04-1.13) and anal HPV types (aOR, 1.11; 95% CI, 1.05-1.17). The largest effect sizes were observed with nonvaccine types HPV-56 and HPV-68.

CONCLUSIONS AND RELEVANCE

Whereas lower detection rates of vaccine-related HPV types were observed since introduction of vaccines in female youth in New York City, rates of some nonvaccine high-risk HPV types were higher. Continued monitoring of high-risk HPV prevalence is warranted.

Natural Language Processing for Surveillance of Cervical and Anal Cancer and Precancer: Algorithm Development and Split-Validation Study

Background

Accurate identification of new diagnoses of human papillomavirus–associated cancers and precancers is an important step toward the development of strategies that optimize the use of human papillomavirus vaccines. The diagnosis of human papillomavirus cancers hinges on a histopathologic report, which is typically stored in electronic medical records as free-form, or unstructured, narrative text. Previous efforts to perform surveillance for human papillomavirus cancers have relied on the manual review of pathology reports to extract diagnostic information, a process that is both labor- and resource-intensive. Natural language processing can be used to automate the structuring and extraction of clinical data from unstructured narrative text in medical records and may provide a practical and effective method for identifying patients with vaccine-preventable human papillomavirus disease for surveillance and research.

Objective

This study's objective was to develop and assess the accuracy of a natural language processing algorithm for the identification of individuals with cancer or precancer of the cervix and anus.

Methods

A pipeline-based natural language processing algorithm was developed, which incorporated machine learning and rule-based methods to extract diagnostic elements from the narrative pathology reports. To test the algorithm’s classification accuracy, we used a split-validation study design. Full-length cervical and anal pathology reports were randomly selected from 4 clinical pathology laboratories. Two study team members, blinded to the classifications produced by the natural language processing algorithm, manually and independently reviewed all reports and classified them at the document level according to 2 domains (diagnosis and human papillomavirus testing results). Using the manual review as the gold standard, the algorithm’s performance was evaluated using standard measurements of accuracy, recall, precision, and F-measure.

Results

The natural language processing algorithm’s performance was validated on 949 pathology reports. The algorithm demonstrated accurate identification of abnormal cytology, histology, and positive human papillomavirus tests with accuracies greater than 0.91. Precision was lowest for anal histology reports (0.87, 95% CI 0.59-0.98) and highest for cervical cytology (0.98, 95% CI 0.95-0.99). The natural language processing algorithm missed 2 out of the 15 abnormal anal histology reports, which led to a relatively low recall (0.68, 95% CI 0.43-0.87).

Conclusions

This study outlines the development and validation of a freely available and easily implementable natural language processing algorithm that can automate the extraction and classification of clinical data from cervical and anal cytology and histology.

The role of epidemiology in informing United States childhood immunization policy and practice

One of the ten greatest public health achievements is childhood vaccination because of its impact on controlling and eliminating vaccine-preventable diseases (VPDs). Evidence-based immunization policies and practices are responsible for this success and are supported by epidemiology that has generated scientific evidence for informing policy and practice. The purpose of this report is to highlight the role of epidemiology in the development of immunization policy and successful intervention in public health practice that has resulted in a measurable public health impact: the control and elimination of VPDs in the United States. Examples in which epidemiology informed immunization policy were collected from a literature review and consultation with experts who have been working in this field for the past 30 years. Epidemiologic examples (e.g., thimerosal-containing vaccines and the alleged association between the measles, mumps, and rubella (MMR) vaccine and autism) are presented to describe challenges that epidemiologists have addressed. Finally, we describe ongoing challenges to the nation's ability to sustain high vaccination coverage, particularly with concerns about vaccine safety and effectiveness, increasing use of religious and philosophical belief exemptions to vaccination, and vaccine hesitancy. Learning from past and current experiences may help epidemiologists anticipate and address current and future challenges to respond to emerging infectious diseases, such as COVID-19, with new vaccines and enhance the public health impact of immunization programs for years to come.

Trends in High-grade Cervical Lesions and Cervical Cancer Screening in 5 States, 2008-2015

BACKGROUND

We describe changes in rates of cervical intraepithelial neoplasia grades 2, 3 and adenocarcinoma in situ (CIN2+) during a period of human papillomavirus (HPV) vaccine uptake and changing cervical cancer screening recommendations.

METHODS

We conducted population-based laboratory surveillance for CIN2+ in catchment areas in 5 states, 2008-2015. We calculated age-specific CIN2+ rates per 100000 women by age groups. We estimated incidence rate ratios (IRR) of CIN2+ for 2-year periods among all women and among screened women to evaluate changes over time.

RESULTS

A total of 16572 CIN2+ cases were reported. Among women aged 18-20 and 21-24 years, CIN2+ rates declined in all sites, whereas in women aged 25-29, 30-34, and 35-39 years, trends differed across sites. The percent of women screened annually declined in all sites and age groups. Compared to 2008-2009, rates among screened women were significantly lower for all 3 periods in women aged 18-20 years (2010-2011: IRR 0.82, 95% confidence interval [CI] 0.67-0.99; 2012-2013: IRR 0.63, 95% CI 0.47-0.85; 2014-2015: IRR 0.44, 95% CI 0.28-0.68) and lower for the latter 2 time periods in women aged 21-24 years (2012-2013: IRR 0.86, 95% CI 0.79-0.94; 2014-2015: IRR 0.61, 95% CI 0.55-0.67).

CONCLUSIONS

From 2008-2015, both CIN2+ rates and cervical cancer screening declined in women aged 18-24 years. The significant decreases in CIN2+ rates among screened women aged 18-24 years are consistent with a population-level impact of HPV vaccination.

Effectiveness of 1, 2, and 3 Doses of Human Papillomavirus Vaccine Against High-Grade Cervical Lesions Positive for Human Papillomavirus 16 or 18

Before 2016, human papillomavirus (HPV) vaccination was recommended on a 3-dose schedule. However, many vaccine-eligible US females received fewer than 3 doses, which provided an opportunity to evaluate the real-world vaccine effectiveness (VE) of 1, 2, and 3 doses. We analyzed data on cervical intraepithelial neoplasia (CIN) grades 2-3 and adenocarcinoma in situ (designated CIN2+) from the HPV Vaccine Impact Monitoring Project (HPV-IMPACT; 2008-2014). Archived tissue from CIN2+ lesions was tested for 37 types of HPV. Women were classified by number of doses received ≥24 months before CIN2+ detection. Using a test-negative design, VE was estimated as 1 minus the adjusted odds ratio from a logistic regression model that compared vaccination history for women whose lesions tested positive for HPV-16/18 (vaccine-type cases) with that for women who had all other CIN2+ lesions (controls). Among 3,300 women with available data on CIN2+, typing results, and vaccine history, 1,561 (47%) were HPV-16/18-positive, 136 (4%) received 1 dose of HPV vaccine, 108 (3%) received 2 doses, and 325 (10%) received 3 doses. Adjusted odds ratios for vaccination with 1, 2, and 3 doses were 0.53 (95% confidence interval (CI): 0.37, 0.76; VE = 47%), 0.45 (95% CI: 0.30, 0.69; VE = 55%), and 0.26 (95% CI: 0.20, 0.35; VE = 74%), respectively. We found significant VE against vaccine-type CIN2+ after 3 doses of HPV vaccine and lower but significant VE with 1 or 2 doses.

Prevalence of cervical disease at age 20 after immunisation with bivalent HPV vaccine at age 12-13 in Scotland: retrospective population study

OBJECTIVE

To quantify the effect on cervical disease at age 20 years of immunisation with bivalent human papillomavirus (HPV) vaccine at age 12-13 years.

DESIGN

Retrospective population study, 1988-96.

SETTING

National vaccination and cervical screening programmes in Scotland.

PARTICIPANTS

138 692 women born between 1 January 1988 and 5 June 1996 and who had a smear test result recorded at age 20.

MAIN OUTCOME MEASURES

Effect of vaccination on cytology results and associated histological diagnoses from first year of screening (while aged 20), calculated using logistic regression.

RESULTS

138 692 records were retrieved. Compared with unvaccinated women born in 1988, vaccinated women born in 1995 and 1996 showed an 89% reduction (95% confidence interval 81% to 94%) in prevalent cervical intraepithelial neoplasia (CIN) grade 3 or worse (from 0.59% (0.48% to 0.71%) to 0.06% (0.04% to 0.11%)), an 88% reduction (83% to 92%) in CIN grade 2 or worse (from 1.44% (1.28% to 1.63%) to 0.17% (0.12% to 0.24%)), and a 79% reduction (69% to 86%) in CIN grade 1 (from 0.69% (0.58% to 0.63%) to 0.15% (0.10% to 0.21%)). Younger age at immunisation was associated with increasing vaccine effectiveness: 86% (75% to 92%) for CIN grade 3 or worse for women vaccinated at age 12-13 compared with 51% (28% to 66%) for women vaccinated at age 17. Evidence of herd protection against high grade cervical disease was found in unvaccinated girls in the 1995 and 1996 cohorts.

CONCLUSIONS

Routine vaccination of girls aged 12-13 years with the bivalent HPV vaccine in Scotland has led to a dramatic reduction in preinvasive cervical disease. Evidence of clinically relevant herd protection is apparent in unvaccinated women. These data are consistent with the reduced prevalence of high risk HPV in Scotland. The bivalent vaccine is confirmed as being highly effective vaccine and should greatly reduce the incidence of cervical cancer. The findings will need to be considered by cervical cancer prevention programmes worldwide.

Trends in Human Papillomavirus Vaccine Types 16 and 18 in Cervical Precancers, 2008-2014

BACKGROUND

The impact of human papillomavirus (HPV) vaccination has been observed in the United States through declining cervical precancer incidence in young women. To further evaluate vaccine impact, we described trends in HPV vaccine types 16/18 in cervical precancers, 2008-2014.

METHODS

We analyzed data from a 5-site, population-based surveillance system. Archived specimens from women age 18-39 years diagnosed with cervical intraepithelial neoplasia grades 2-3 or adenocarcinoma in situ (CIN2+) were tested for 37 HPV types. We described the proportion and estimated number of cases of CIN2+ by HPV-type groups over time. Trends in HPV16/18-positive CIN2+ were examined, overall and by vaccination status, age, histologic grade, and race/ethnicity, using Cochrane-Armitage tests.

RESULTS

In 10,206 cases, the proportion and estimated number of cases of HPV16/18-positive CIN2+ declined from 52.7% (1,235 cases) in 2008 to 44.1% (819 cases) in 2014 (P < 0.001). Declining trends in the proportion of HPV16/18-positive CIN2+ were observed among vaccinated (55.2%-33.3%, P < 0.001) and unvaccinated (51.0%-47.3%, P = 0.03) women; ages 18-20 (48.7%-18.8%, P = 0.02), 21-24 (53.8%-44.0%, P < 0.001), 25-29 (56.9%-42.4%, P < 0.001), and 30-34 (49.8%-45.8%, P = 0.04) years; CIN2 (40.8%-29.9%, P < 0.001) and CIN2/3 (61.8%-46.2%, P < 0.001); non-Hispanic white (59.5%-47.9%, P < 0.001) and non-Hispanic black (40.7%-26.5%, P < 0.001).

CONCLUSIONS

From 2008-2014, the proportion of HPV16/18-positive CIN2+ declined, with the greatest declines in vaccinated women; declines in unvaccinated women suggest herd protection.

IMPACT

The declining proportion of HPV16/18-positive CIN2+ provides additional evidence of vaccine impact in the United States.

Prevalence of high-risk human papilloma virus in women with high-grade squamous cell intraepithelial lesions in Botswana using Abbott RealTime HPV assay

BACKGROUND

High-risk human papillomavirus (HR-HPV) has been demonstrated to be the necessary cause of cervical carcinoma. High-risk HPV detection has a prognostic significance for the women who are at increased risk of disease progression. HPV genotyping in cervical cancer precursor lesions is crucial for prevention and management of cervical cancer. This study was designed to investigate the distribution of HR-HPV genotypes among a group of patients with high-grade squamous intraepithelial lesions and higher, of the cervix, in Botswana.

MATERIALS AND METHODS

185-archived residual formalin-fixed paraffin-embedded cervical biopsies collected between the years, 2006 and 2008 were studied. These tissues were diagnosed with HSIL (n = 146) and squamous cell carcinoma (n = 39). DNA was extracted using the Abbott m2000 analyser (Abbott Laboratories, Illinois) using reagents provided by the manufacturer. HPV genotyping was done using the Abbott RealTime HR-HPV PCR, which qualitatively detects 14 HR-HPV (reported as HPV 16, 18 & Other HR-HPV).

RESULTS

DNA was successfully extracted from 162/185 (87.6%) tissues as indicated by a positive β-globin test. 132/162 (82%) tested positive for HR-HPV The HPV 16 prevalence was 50% (66/132), HPV 18 at 15.2% (20/132) and other Group 1 HR-HPV plus HPV 66 and 68 had a prevalence of 56.1% (74/132). Other HR-HPV types were common in HSIL than in carcinoma, while HPV 16 was more prevalent in carcinomas than other HR-HPV genotypes.

CONCLUSION

In this study, HPV 16 and other HR-HPV genotypes were commonly associated with HSIL but HPV 18 was uncommon among Botswana women. Our data highlights the need for multivalent HPV vaccines with cross coverage for other high risk HPV other than HPV 16 and 18.

Persistence of memory B-cell and T-cell responses to the quadrivalent HPV vaccine in HIV-infected children

OBJECTIVE

To determine the magnitude and persistence of quadrivalent human papillomavirus (HPV)16 and HPV18 B-cell and T-cell memory after three or four doses of quadrivalent HPV vaccine (QHPV) in HIV-infected children.

METHODS

Seventy-four HIV-infected children immunized with four doses and 23 with three doses of QHPV had HPV16 and HPV18 IgG B-cell and IFNγ and IL2 T-cell ELISPOT performed at 2, 3.5 and 4-5 years after the last dose.

RESULTS

HPV16 and HPV18 T-cell responses were similar in both treatment groups, with higher responses to HPV16 vs. HPV18. These HPV T-cell responses correlated with HIV disease characteristics at the study visits. Global T-cell function declined over time as measured by nonspecific mitogenic stimulation. B-cell memory was similar across treatment groups and HPV genotypes. There was a decline in HPV-specific B-cell memory over time that reached statistical significance for HPV16 in the four-dose group.

CONCLUSION

B-cell and T-cell memory did not significantly differ after either three or four doses of QHPV in HIV-infected children. The clinical consequences of decreasing global T-cell function and HPV B-cell memory over time in HIV-infected children requires further investigation.

Surveillance of high-grade cervical cancer precursors (CIN III/AIS) in four population-based cancer registries, United States, 2009-2012

Surveillance of cervical intraepithelial neoplasia grade III (CIN III) and adenocarcinoma in situ (AIS) is important for determining the burden of a preventable disease, identifying effects of vaccination on future diagnoses, and developing targeted programs. We analyzed population-based rates of high-grade cervical cancer precursor lesions using data from four central cancer registries (diagnosis years 2009-2012 from Louisiana, Kentucky, Michigan, and diagnosis years 2011-2012 from Los Angeles) by age, race, and histology. We also compared rates of precursors to invasive cancers. With 4 complete years of data from Michigan, we were able to conduct a trend analysis for that state. Data analysis was conducted in Atlanta during 2016. Kentucky reported the highest rate of CIN III/AIS (69.8), followed by Michigan (55.4), Louisiana (42.3), and Los Angeles (19.2). CIN III/AIS rates declined among women in Michigan by 37% each year for women aged 15-19, 14% for those aged 20-24, and 7% for those aged 25-29. Rates of CIN III/AIS vary by registry, and were higher than invasive cancer. In Michigan, declines in CIN III/AIS among women aged 15-29 are likely related in part to updated screening recommendations, and to the impact of human papillomavirus vaccination.

Cervical cancer screening in the era of HPV vaccination: A review of shifting paradigms in cytopathology

Significant changes in cervical cancer screening practice, guidelines, and prevention of cervical cancer have taken place in recent years including the raising of initial cervical cancer screening age, changes in frequency of cytology screening, and the adoption of high risk HPV and cytology co-testing for some patients; the introduction of the bivalent, quadrivalent, and 9-valent HPV vaccines; and the recent approval of high risk HPV testing as primary screening with the use of cytology as triage in positive cases. This review discusses the significance of primary HPV screening, the impact of HPV vaccination in the prevalence of cervical cancer and its precursors, the interplay between high risk HPV testing and vaccination, and the implications for clinical and cytological management. Future strategies for cervical screening in the post-vaccination era are also discussed.

Population-Based Incidence Rates of Cervical Intraepithelial Neoplasia in the Human Papillomavirus Vaccine Era

IMPORTANCE

A substantial effect of human papillomavirus (HPV) vaccines on reducing HPV-related cervical disease is essential before modifying clinical practice guidelines in partially vaccinated populations.

OBJECTIVE

To determine the population-based cervical intraepithelial neoplasia (CIN) trends when adjusting for changes in cervical screening practices that overlapped with HPV vaccination implementation.

DESIGN, SETTING, AND PARTICIPANTS

The New Mexico HPV Pap Registry, which captures population-based estimates of both cervical screening prevalence and CIN, was used to compute CIN trends from January 1, 2007, to December 31, 2014. Under New Mexico Administrative Code, the New Mexico HPV Pap Registry, a statewide public health surveillance program, receives mandatory reporting of all cervical screening (cytologic and HPV testing) and any cervical, vulvar, and vaginal histopathological findings for all women residing in New Mexico irrespective of outcome.

MAIN OUTCOME MEASURES

Prespecified outcome measures included low-grade CIN (grade 1 [CIN1]) and high-grade CIN (grade 2 [CIN2] and grade 3 [CIN3]).

RESULTS

From 2007 to 2014, a total of 13 520 CIN1, 4296 CIN2, and 2823 CIN3 lesions were diagnosed among female individuals 15 to 29 years old. After adjustment for changes in cervical screening across the period, reductions in the CIN incidence per 100 000 women screened were significant for all grades of CIN among female individuals 15 to 19 years old, dropping from 3468.3 to 1590.6 for CIN1 (annual percentage change [APC], -9.0; 95% CI, -12.0 to -5.8; P < .001), from 896.4 to 414.9 for CIN2 (APC, -10.5; 95% CI, -18.8 to -1.2; P = .03), and from 240.2 to 0 for CIN3 (APC, -41.3; 95% CI, -65.7 to 0.3; P = .05). Reductions in the CIN2 incidence were also significant for women 20 to 24 years old, dropping from 1027.7 to 627.1 (APC, -6.3; 95% CI, -10.9 to -1.4; P = .02).

CONCLUSIONS AND RELEVANCE

Population-level decreases in CIN among cohorts partially vaccinated for HPV may be considered when clinical practice guidelines for cervical cancer screening are reassessed. Evidence is rapidly growing to suggest that further increases in raising the age to start screening are imminent, one step toward integrating screening and vaccination.

Comparison of methods using paraffin-embedded tissues and exfoliated cervical cells to evaluate human papillomavirus genotype attribution

Monitoring the attribution of human papillomavirus (HPV) genotypes to cervical precancerous lesions is essential in assessing the efficacy of HPV vaccines. To resolve the lack of studies comparing the HPV genotyping procedures used to estimate HPV genotype attribution, we undertook a retrospective cross-sectional study to determine the appropriate genotyping procedures for evaluating the potential efficacy of HPV vaccines. Three procedures, including two different genotyping methods, Clinichip HPV test (C-Chip) and modified GP5+/6+ PCR coupled to fluorescent bead sorter detection (MGP), using exfoliated cervical cells (C-Chip and C-MGP, respectively) or formalin-fixed paraffin-embedded tissues (F-MGP), were compared. The overall agreement in detecting high-risk HPV was 88.5-92.1% among the three procedures, and genotype-specific agreement was 83.9-100% for all pairwise comparisons. In cervical intraepithelial neoplasia grade 2/3 specimens, HPV16/18 attribution estimated with the hierarchical attribution method was consistent among the procedures: 52.3% (45/86) for C-Chip, 54.7% (47/86) for C-MGP, and 52.3% (45/86) for F-MGP (P = 0.81). HPV16/18/31/33/45/52/58 hierarchical attribution was 88.4% (76/86) with C-Chip, 86.0% (74/86) with C-MGP, and 83.7% (72/86) with F-MGP (P = 0.49). In cervical intraepithelial neoplasia grade 3 specimens, the corresponding hierarchical attribution was 96.4% (53/55) with C-Chip, 89.1% (49/55) with C-MGP, and 94.5% (52/55) with F-MGP (P = 0.27). Although F-MGP is theoretically a reliable method for determining HPV genotype attribution, it is acceptable to use C-Chip or C-MGP, coupled to the hierarchical attribution formula to correct the bias of multiple infections. These approaches using exfoliated cervical cells are practical for monitoring the efficacy of HPV vaccines.

A Bivariate Mixture Model for Natural Antibody Levels to Human Papillomavirus Types 16 and 18: Baseline Estimates for Monitoring the Herd Effects of Immunization

Post-vaccine monitoring programs for human papillomavirus (HPV) have been introduced in many countries, but HPV serology is still an underutilized tool, partly owing to the weak antibody response to HPV infection. Changes in antibody levels among non-vaccinated individuals could be employed to monitor herd effects of immunization against HPV vaccine types 16 and 18, but inference requires an appropriate statistical model. The authors developed a four-component bivariate mixture model for jointly estimating vaccine-type seroprevalence from correlated antibody responses against HPV16 and -18 infections. This model takes account of the correlation between HPV16 and -18 antibody concentrations within subjects, caused e.g. by heterogeneity in exposure level and immune response. The model was fitted to HPV16 and -18 antibody concentrations as measured by a multiplex immunoassay in a large serological survey (3,875 females) carried out in the Netherlands in 2006/2007, before the introduction of mass immunization. Parameters were estimated by Bayesian analysis. We used the deviance information criterion for model selection; performance of the preferred model was assessed through simulation. Our analysis uncovered elevated antibody concentrations in doubly as compared to singly seropositive individuals, and a strong clustering of HPV16 and -18 seropositivity, particularly around the age of sexual debut. The bivariate model resulted in a more reliable classification of singly and doubly seropositive individuals than achieved by a combination of two univariate models, and suggested a higher pre-vaccine HPV16 seroprevalence than previously estimated. The bivariate mixture model provides valuable baseline estimates of vaccine-type seroprevalence and may prove useful in seroepidemiologic assessment of the herd effects of HPV vaccination.

Cultivation of an Adaptive Domestic Network for Surveillance and Evaluation of Emerging Infections

Accomplishments of this program have provided numerous dividends and might benefit areas outside infectious diseases.