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Background In the Netherlands, the bivalent human papillomavirus (HPV) vaccine has been offered to preadolescent girls via the National Immunization Program in a 2-dose schedule since 2014. The current study estimates vaccine effectiveness (VE) against HPV infections up to 4 years postvaccination among girls eligible for routine 2-dose immunization. Methods A cohort study (HAVANA2) was used in which participants annually filled out an online questionnaire and provided a vaginal self-sample for determination of HPV by the SPF10-LiPA25 assay, able to detect 25 HPV types. VE against incident type-specific infections and pooled outcomes was estimated by a Cox proportional hazards model with shared frailty between the HPV types. Results In total, 2027 girls were included in the study, 1098 (54.2%) of whom were vaccinated with 2 doses. Highest incidence rate was 5.0/1000 person-years (HPV-51) among vaccinated participants and 9.1/1000 person-years (HPV-74) among unvaccinated participants. Adjusted pooled VE was 84.0% (95% confidence interval [CI], 27.0%–96.5%) against incident HPV-16/18 infections and 86.5% (95% CI, 39.5%–97.08%) against cross-protective types HPV-31/33/45. Conclusions Four years postvaccination, 2 doses of bivalent HPV vaccine were effective in the prevention of incident HPV-16/18 infections and provided cross-protection to HPV-31/33/45. Our VE estimates rival those from 3-dose schedules, indicating comparable protection by 2-dose schedules.

The current study describes the long-term effectiveness of three-dose HPV16/18 vaccination among Dutch women who were eligible for vaccination during a catch-up campaign and were followed in an observational cohort study. Ten years post vaccination, vaccine effectiveness (VE) was estimated using generalized estimating equation models. VE against persistent infections with vaccine type infections (HPV16/18) was high at 95.8%. For cross protective type persistent infections (HPV31/33/45) this was 64.6%. There were no indications of waning of protection over time. This indicates solid long-term protection is provided by the vaccine and is promising with regard to the future clinical impact.

Approaches to estimating clearance rates, an important metric of human papillomavirus (HPV) clearance, for HPV groupings differ between studies. We aimed to identify the approaches used in the literature for estimating grouped HPV clearance rates. We investigated whether these approaches resulted in different estimations, using data from existing studies.In this systematic review, we included articles that reported clearance rates of HPV groupings. We identified approaches to data in the HAVANA cohort, comprising adolescent girls, and the H2M cohort, comprising men who have sex with men. We estimated clearance rates for six HPV groupings (bivalent-, quadrivalent- and nonavalent vaccine-related, and low-risk, high-risk, and any HPV).From 26 articles, we identified 54 theoretically possible approaches to estimating clearance rates. These approaches varied regarding definitions of clearance events and person-time, and prevalence or incidence of infections included in the analysis. Applying the nine most-used approaches to the HAVANA ( n = 1,394) and H2M ( n = 745) cohorts demonstrated strong variation in clearance rate estimates depending on the approach used. For example, for grouped high-risk HPV in the H2M cohort, clearance rates ranged from 52.4 to 120.0 clearances/1000 person-months. Clearance rates also varied in the HAVANA cohort, but differences were less pronounced, ranging from 24.1 to 57.7 clearances/1000 person-months.Varied approaches from the literature for estimating clearance rates of HPV groupings yielded different clearance rate estimates in our data examples. Estimates also varied between study populations. We advise clear reporting of methodology and urge caution in comparing clearance rates between studies.

Background Human papillomavirus (HPV) vaccination programs achieve substantial population-level impact, with effects extending beyond protection of vaccinated individuals. We assessed trends in HPV prevalence up to 8 years postvaccination among men and women in the Netherlands, where bivalent HPV vaccination, targeting HPV types 16/18, has been offered to (pre)adolescent girls since 2009 with moderate vaccination coverage. Methods We used data from the PASSYON study, a survey initiated in 2009 (prevaccination) and repeated biennially among 16- to 24-year-old visitors of sexual health centers. We studied genital HPV positivity from 2009 to 2017 among women, heterosexual men, and unvaccinated women using Poisson generalized estimating equation models, adjusted for individual- and population-level confounders. Trends were studied for 25 HPV types detected by the SPF10-LiPA25 platform. Results A total of 6354 women (64.7% self-reported unvaccinated) and 2414 heterosexual men were included. Percentual declines in vaccine types HPV-16/18 were observed for all women (12.6% per year [95% confidence interval {CI}, 10.6–14.5]), heterosexual men (13.0% per year [95% CI, 8.3–17.5]), and unvaccinated women (5.4% per year [95% CI, 2.9–7.8]). We observed significant declines in HPV-31 (all women and heterosexual men), HPV-45 (all women), and in all high-risk HPV types pooled (all women and heterosexual men). Significant increases were observed for HPV-56 (all women) and HPV-52 (unvaccinated women). Conclusions Our results provide evidence for first-order herd effects among heterosexual men against HPV-16/18 and cross-protective types. Additionally, we show second-order herd effects against vaccine types among unvaccinated women. These results are promising regarding population-level and clinical impact of girls-only bivalent HPV vaccination in a country with moderate vaccine uptake., This study presents trends in human papillomavirus (HPV) positivity since girls-only HPV vaccine introduction in the Netherlands, with moderate vaccine uptake. We show declining prevalences of vaccine types HPV-16/18 in heterosexual men and unvaccinated women, and of cross-protective types in heterosexual men.

Background: In the Netherlands, bivalent human papillomavirus (HPV) vaccination was included in the National Immunization Program for 12-year-old girls in 2010 (vaccination coverage, 45%–60%). We examined possible changes in HPV seroprevalence in the HPV-unvaccinated Dutch population aged 0–89 years, comparing prevaccination data with data of approximately 6 years after implementation of national vaccination. Methods: Serum samples of men and women were used from two cross-sectional population-based serosurveillance studies performed before (2006–07, n = 6,384) and after (2016–17, n = 5,645) implementation of HPV vaccination in the Netherlands. Seven high-risk HPV-specific antibodies (HPV16, 18, 31, 33, 45, 52, and 58) were tested in a virus-like particle-based multiplex immunoassay. Results: Type-specific HPV seroprevalence increased in women between 2006–07 and 2016–17. Also, a higher seroprevalence for at least one type in women >15 years was found in 2016–17 (31.7%) compared with 2006–07 (25.2%). In men, overall HPV seroprevalence remained similar; however, a lower seroprevalence was found for HPV16 in 2016–17 (7.5%) compared with 2006–07 (10.6%). Conclusions: Our results indicate an increase in high-risk HPV types in women and a rather stable exposure in men. No clear effects of the strategy of girls-only vaccination were observed in men, probably because of the short time after introduction combined with suboptimal coverage. Impact: No herd immunity has been observed yet in a population with suboptimal HPV vaccination coverage.

The bivalent human papillomavirus (HPV) vaccine is highly effective and induces robust serological responses. Using a Dutch prospective cohort initiated in 2009, including 744 vaccinated and 294 unvaccinated girls (1993–1994) who provide a vaginal self-swab sample, serum sample, and questionnaire yearly, we report a high, persisting antibody response up to 9 years after vaccination for vaccine types HPV-16 or HPV-18. Antibodies against nonvaccine HPV types 31, 33, 45, 52, and 58 were lower but still significantly higher than in unvaccinated individuals. This was also reflected in the seroprevalence. We compared participant characteristics and antibody levels between vaccinated women with and those without HPV infections 1 year before infection (204 incident and 64 persistent infections), but we observed no consistent difference in type-specific antibody levels. Having a high-risk HPV infection was associated with sexual risk behavior and smoking 1 year before infection. Although high antibody levels are necessary for protection, our study suggests that on the individual level other factors such as HPV exposure or antibody avidity could be important.

Background Persistent high-risk human papillomavirus (HPV) infection is endorsed by the World Health Organization as an intermediate endpoint for evaluating HPV vaccine effectiveness/efficacy. There are different approaches to estimate the vaccine effectiveness/efficacy against persistent HPV infections. Methods We performed a systematic literature search in Pubmed to identify statistical approaches that have been used to estimate the vaccine effectiveness/efficacy against persistent HPV infections. We applied these methods to data of a longitudinal observational study to assess their performance and compare the obtained vaccine effectiveness (VE) estimates. Results Our literature search identified four approaches: the conditional exact test for comparing two independent Poisson rates using a binomial distribution, Generalized Estimating Equations for Poisson regression, Prentice Williams and Peterson total time (PWP-TT) and Cox proportional hazards regression. These approaches differ regarding underlying assumptions and provide different effect measures. However, they provided similar effectiveness estimates against HPV16/18 and HPV31/33/45 persistent infections in a cohort of young women eligible for routine HPV vaccination (range VE 93.7–95.1% and 60.4–67.7%, respectively) and seemed robust to violations of underlying assumptions. Conclusions As the rate of subsequent infections increased in our observational cohort, we recommend PWP-TT as the optimal approach to estimate the vaccine effectiveness against persistent HPV infections in young women. Confirmation of our findings should be undertaken by applying these methods after longer follow-up in our study, as well as in different populations.

Infectious diseases can differ by sex in their incidence, prevalence, or severity of disease. These differences may be induced by sex-dependent immune responses and resulting protection, for example after vaccination. Therefore, this study aims to assess possible sex-differences in immunoglobulin levels (IgG) after infant and childhood vaccination.Data from a national cross-sectional serosurvey conducted in 2006/2007 were used (Pienter 2). We compared IgG levels against measles, mumps, rubella, diphtheria, tetanus, poliomyelitis, pertussis, Haemophilus influenzae type b (Hib), and Neisseria meningitidis serogroup C (MenC) between girls and boys both short term (1 month to 1 year) and long term (1-3 year) after infant and childhood vaccinations, using linear regression analysis. Proportions of boys and girls reaching a protective IgG level were compared using Fishers exact test.Differences in IgG were found at specific time points after vaccination against measles, mumps, rubella, MenC, and polio. The geometric mean concentration or titer (GMC/T) girls:boys ratios ranged between 1.10 for polio type 11 year after the first childhood booster to 1.90 for MenC1 year after infant vaccination, indicating higher antibody levels in girls. No significant differences were found between boys and girls for diphtheria, tetanus, pertussis, and Hib at either time point. Proportions with protective levels differed only at 1-3 years after infant vaccination for mumps (82.5% boys vs. 91.9% girls, p = 0.046), and at the same time point for MenC (7.0% boys vs. 18.2% girls, p = 0.015), and polio type 1 (87.8% boys vs. 95.9% girls, p = 0.047).Differences in IgG between boys and girls were generally small and not consistent, neither between pathogens nor within pathogens. If differences were observed, girls were favored over boys. On the whole, the results suggest that there are no major sex differences in protection from the studied pathogens in the Netherlands.

Ojective Despite vaccination, pertussis has remained endemic, sometimes leading to severe disease. We aimed to quantify the completeness of reporting (CoR) of pertussis hospitalizations and deaths in the Netherlands. Study design CoR was estimated using capture-recapture analyses. Hospitalizations (2007–2014) from the National Registration Hospital Care (hospital data) were matched to the notifiable Infectious Disease case registry (notifications) providing (month and) year of birth, gender and postal code. Deaths (1996–2014) from Statistics Netherlands (death registry) were matched to notifications using gender, age, year of death and notification date. Cases