Changes in (risk) behavior and HPV knowledge among Dutch girls eligible for HPV vaccination: an observational cohort study.

Implementation of human papillomavirus (HPV) vaccination raised concerns that vaccination could lead to riskier sexual behavior. This study explored how possible differences in sexual behavior and HPV knowledge developed over time between HPV-vaccinated and unvaccinated girls

Bivalent Vaccine Effectiveness Against Type-Specific HPV Positivity: Evidence for Cross-Protection Against Oncogenic Types Among Dutch STI Clinic Visitors.

Observational postmarketing studies are important to assess vaccine effectiveness (VE). We estimated VE from the bivalent human papillomavirus (HPV) vaccine against HPV positivity of vaccine and nonvaccine types in a high-risk population

Effect of human papillomavirus vaccination on sexual behaviour among young females

Question At the time of implementation of human papillomavirus (HPV) vaccine immunization programs, concerns were raised by parents, clinicians, and public health professionals about HPV vaccination possibly leading to riskier sexual health choices among young females. If HPV vaccination influences sexual behaviour among vaccinated females, this might influence the effect of HPV vaccination programs. What is known about the effects of the HPV vaccination program on sexual behaviour among young females? Answer Human papillomavirus vaccination has not been associated with increased sexual risk behaviour among young females. However, currently available studies have some important limitations, and future studies should focus on a longitudinal design that includes a prevaccination baseline measurement, adjustment for possible confounders, and measurement of both clinical indicators and behavioural outcomes

Non-inferior antibody levels for HPV16/18 after extended two-dose schedules compared with a six-month interval: findings of a systematic review and meta-analysis

Protection after human papillomavirus (HPV) vaccination can be maximized by optimizing vaccination schedules. We systematically reviewed immunogenicity and effectiveness of HPV vaccines administered 6 months apart compared with longer intervals. Seroconversion to vaccine-type HPV was non-inferior for 12- compared with 6-month intervals, but inconclusive for comparison of 36-96 months with 6 months. A 12-month interval showed non-inferior (margin 0.5) vaccine-type HPV antibody responses compared with a 6-month interval. Compared to 6 months, an interval of 36-96 months resulted in non-inferior antibody responses for HPV6 and high-risk types HPV16 and 18, but did not lead to a non-inferior antibody response for HPV11 (GMR 0.63, 95% CI:0.41-0.97). Data on the effectiveness of extended two-dose schedules were limited. Our findings indicate that HPV immunization programs could adopt a 12-month interval instead of 6 months for increased flexibility without compromising immunogenicity. Further evaluation to confirm the immunogenicity and effectiveness of intervals beyond 12 months is warranted

Age-Specific Trends of Invasive Cervical Cancer Incidence in British Columbia, Canada, 1971–2017

This study examined invasive cervical cancer (ICC) incidence trends in British Columbia (BC) by age and stage-at-diagnosis relative to World Health Organization ICC elimination targets (4 per 100,000 persons). Incident ICC cases (1971–2017) were obtained from the BC Cancer Registry. Annual age-standardized incidence rates (ASIRs) per 100,000 persons were generated using the direct method. ASIRs were examined among all ages 15+ years and eight age groups using Joinpoint Regression with the Canadian 2011 standard population. Standardized rate ratios (SRRs) compared stage II–IV (late) versus stage I (early) ASIRs by age (2010–2017). ICC ASIRs did not reach the elimination target. ASIRs declined from 18.88 to 7.08 per 100,000 persons (1971–2017). Stronger declines were observed among ages 45+ years, with the largest decline among ages 70–79 years (AAPC = −3.2%, 95% CI = −3.9% to −2.6%). Among ages 25–69 years, varying levels of attenuation in declining trends and stabilization were observed since the 1980s. SRRs indicated higher rates of late-stage ICC among ages 55+ years (SRR−55–69 years = 1.34, 95% CI = 1.08–1.71). Overall, ICC incidence declined in BC since 1971 but did not reach the elimination target. The pace of decline varied across age groups and increased with age. Continued efforts are needed to progress cervical cancer elimination among all age groups.Medicine, Faculty ofOther UBCNon UBCPopulation and Public Health (SPPH), School ofReviewedFacultyResearche

Factors associated with interest in bacterial sexually transmitted infection vaccines at two large sexually transmitted infection clinics in British Columbia, Canada

Objective To explore sexually transmitted infection (STI) clinic client attitudes and preferences towards STI vaccines and STI vaccine programming in an urban clinic setting. Methods A 31-item questionnaire was administered during check-in by clinic clerical staff at two STI clinics in Vancouver, Canada. Demographic characteristics and preferences were summarised descriptively. Multivariable logistic regression models to assess factors associated with STI vaccine interest (reported as ORs) were constructed using a priori clinically relevant variables and factors significant at p≤0.05 in bivariate analysis. Results 293 surveys were included in analysis. 71.3% of respondents identified as male, 80.5% had college level education or higher and 52.9% identified as white/of European descent. The median age was 33. 86.5% of respondents reported they would be interested in receiving an STI vaccine, with a primary motivator to protect oneself. Bivariate analysis indicated several factors associated with vaccine interest, with differences for each infection. After adjusting for other variables, willingness to pay for an STI vaccine (OR=3.83, 95% CI 1.29 to 11.38, p=0.02) remained a significant factor for syphilis vaccine interest and intent to engage in future positive health behaviours remained a significant factor for chlamydia (OR=5.94, 95% CI 1.56 to 22.60, p=0.01) and gonorrhoea (OR=5.13, 95% CI 1.45 to 18.07, p=0.01) vaccine interest. Conclusion Respondents expressed a strong willingness to receive STI vaccines. These valuable findings will inform for eventual STI vaccine programme planning and implementation

Factors associated with intention to receive vaccines for bacterial sexually transmitted infections among young HPV-vaccinated Canadian women

Objective: The aim of this study was to explore the acceptability of bacterial STI vaccines among young HPV-vaccinated Canadian women to inform future vaccine program implementation. Methods: A 20-item cross-sectional questionnaire was administered from June 2019 to June 2020 to HPV-vaccinated participants of the pan-Canadian QUEST cohort. Multivariable logistic regression models assessed interest in chlamydia, syphilis, and gonorrhea vaccines using a priori variables and factors significant in bivariate analysis. Results: Of the 1092 respondents analyzed, 82% indicated interest in receiving one or more future STI vaccines. Respondents had a median age of 19.6 years (range 16.9–23.4), and 75% of respondents identified as white/European descent. In adjusted analyses, intent to engage in positive health behaviours was associated with vaccine interest for syphilis (OR = 5.76, 95% CI 4.03–8.27), chlamydia (OR = 5.27, 95% CI 3.66–7.63), and gonorrhea (OR = 5.96, 95% CI 4.15–8.60). Willingness to pay for an STI vaccine was also associated with vaccine interest for syphilis (OR = 2.02, 95% CI 1.29–3.19), chlamydia (OR = 2.41, 95% CI 1.50–3.90), and gonorrhea (OR = 2.29, 95% CI 1.44–3.63). Ever having sexual intercourse and identifying as LGBTQ were significantly associated with vaccine interest for all infections, while age and ever being immunosuppressed were not significant in any adjusted models. Conclusion: Findings indicate over 80% of participants in a cohort of young HPV-vaccinated Canadian women are interested in receiving future bacterial STI vaccines. Further exploration of STI vaccine acceptability among diverse populations is required to inform future bacterial STI vaccine program implementation

Persistence of immune response following bivalent HPV vaccination: A follow-up study among girls routinely vaccinated with a two-dose schedule.

In this cohort study, we examined antibody levels and avidity after a two-dose schedule (0, 6 months) of the bivalent HPV-vaccine in girls routinely vaccinated in the Dutch HPV-vaccination program, up to 2 years following vaccination. A blood sample at 7, 12 and 24 months after the first dose and questionnaire data were collected (n = 56). HPV type-specific antibody concentrations (lU/ml) against seven types (HPV16/18/31/33/45/52/58) were assessed using a validated virus-like particles (VLP) multiplex immunoassay. Avidity was tested using a modification of this assay. Seropositivity for vaccine types HPV 16 and 18 was 100% up to month 24, but declined for HPV-types 31/33/45/52/58, although not statistically significant for HPV45. All Geometric Mean Concentrations (GMCs) declined by months 12 and 24, but remained high for HPV16/18. Between month 7 and 12, GMCs declined more for other types. High avidity antibodies were induced up to 24 months for vaccine types (75%, 76-78% and 81-82% at months 7, 12 and 24, respectively), but for other types antibody avidity was 16-29% at month 7, 20-32% at month 12 and 19-32% at month 24. GMCs declined over time for HPV-types 16/18/31/33/45/52/58, but remained high for vaccine-types HPV16/18 up to 24 months of follow-up. Antibody avidity was >75% for vaccine types but <35% for other HPV-types. Further follow-up of this cohort will provide insight into antibody and avidity kinetics over time

Persistence of immune response following bivalent HPV vaccination: A follow-up study among girls routinely vaccinated with a two-dose schedule.

In this cohort study, we examined antibody levels and avidity after a two-dose schedule (0, 6 months) of the bivalent HPV-vaccine in girls routinely vaccinated in the Dutch HPV-vaccination program, up to 2 years following vaccination. A blood sample at 7, 12 and 24 months after the first dose and questionnaire data were collected (n = 56). HPV type-specific antibody concentrations (lU/ml) against seven types (HPV16/18/31/33/45/52/58) were assessed using a validated virus-like particles (VLP) multiplex immunoassay. Avidity was tested using a modification of this assay. Seropositivity for vaccine types HPV 16 and 18 was 100% up to month 24, but declined for HPV-types 31/33/45/52/58, although not statistically significant for HPV45. All Geometric Mean Concentrations (GMCs) declined by months 12 and 24, but remained high for HPV16/18. Between month 7 and 12, GMCs declined more for other types. High avidity antibodies were induced up to 24 months for vaccine types (75%, 76-78% and 81-82% at months 7, 12 and 24, respectively), but for other types antibody avidity was 16-29% at month 7, 20-32% at month 12 and 19-32% at month 24. GMCs declined over time for HPV-types 16/18/31/33/45/52/58, but remained high for vaccine-types HPV16/18 up to 24 months of follow-up. Antibody avidity was >75% for vaccine types but <35% for other HPV-types. Further follow-up of this cohort will provide insight into antibody and avidity kinetics over time