Dataset Information

Substantial Decline in Prevalence of Vaccine-Type and Nonvaccine-Type Human Papillomavirus (HPV) in Vaccinated and Unvaccinated Girls 5 Years After Implementing HPV Vaccine in Norway.

ABSTRACT:

Background

In 2009, quadrivalent human papillomavirus (HPV) vaccine was introduced in a school-based single-cohort program targeting 12-year-old girls in Norway. We estimated the impact of the Norwegian HPV immunization program.

Methods

Three birth cohorts of 17-year-old girls, 2 nonvaccine-eligible cohorts (born 1994 or 1996) and 1 vaccine-eligible cohort (born 1997) were invited to deliver urine samples. The samples were analyzed for 37 HPV genotypes. HPV prevalence was compared between birth cohorts and between vaccinated and unvaccinated girls within and across birth cohorts after linkage to the Norwegian Immunisation Registry.

Results

In total, 17749 urine samples were analyzed. A 42% (95% confidence interval [CI], 37%-47%) reduction in any HPV type and 81% (95% CI, 76%-85%) reduction in vaccine types (HPV-6/11/16/18) were observed in the vaccine-eligible cohort compared to the 1994 cohort. Vaccine types were reduced by 54% (95% CI, 39%-66%) and 90% (95% CI, 86%-92%) in unvaccinated and vaccinated girls, respectively, from the 1997 cohort, compared with unvaccinated girls born in 1994. A significant reduction was also observed for several nonvaccine types. Vaccine-type prevalence was reduced by 77% (95% CI, 65%-85%) in vaccinated compared with unvaccinated girls from the 1997 cohort.

Conclusions

In this largely HPV-naive population, we observed a substantial reduction in vaccine and nonvaccine types in vaccinated and unvaccinated girls following introduction of HPV vaccination.

SUBMITTER: Feiring B

PROVIDER: S-EPMC6217723 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Substantial Decline in Prevalence of Vaccine-Type and Nonvaccine-Type Human Papillomavirus (HPV) in Vaccinated and Unvaccinated Girls 5 Years After Implementing HPV Vaccine in Norway.

Feiring Berit B Laake Ida I Christiansen Irene Kraus IK Hansen Mona M Stålcrantz Jeanette J Ambur Ole Herman OH Magnus Per P Jonassen Christine Monceyron CM Trogstad Lill L

The Journal of infectious diseases 20181101 12

<h4>Background</h4>In 2009, quadrivalent human papillomavirus (HPV) vaccine was introduced in a school-based single-cohort program targeting 12-year-old girls in Norway. We estimated the impact of the Norwegian HPV immunization program.<h4>Methods</h4>Three birth cohorts of 17-year-old girls, 2 nonvaccine-eligible cohorts (born 1994 or 1996) and 1 vaccine-eligible cohort (born 1997) were invited to deliver urine samples. The samples were analyzed for 37 HPV genotypes. HPV prevalence was compared ...[more]

PMID: 30010913

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Project description:BackgroundMany countries have initiated school-based human papillomavirus (HPV) vaccination programs. The real-life effectiveness of HPV vaccines has become increasingly evident, especially among girls vaccinated before HPV exposure in countries with high vaccine uptake. In 2009, Norway initiated a school-based HPV vaccination program for 12-year-old girls using the quadrivalent HPV vaccine (Gardasil®), which targets HPV6, 11, 16, and 18. Here, we aim to assess type-specific vaginal and oral HPV prevalence in vaccinated compared with unvaccinated girls in the first birth cohort eligible for school-based vaccination (born in 1997).MethodsThis observational, cross-sectional study measured the HPV prevalence ratio (PR) between vaccinated and unvaccinated girls in Norway. Facebook advertisement was used to recruit participants and disseminate information about the study. Participants self-sampled vaginal and oral specimens using an Evalyn® Brush and a FLOQSwab™, respectively. Sexual behavior was ascertained through a short questionnaire.ResultsAmong the 312 participants, 239 (76.6%) had received at least one dose of HPV vaccine prior to sexual debut. 39.1% of vaginal samples were positive for any HPV type, with similar prevalence among vaccinated and unvaccinated girls (38.5% vs 41.1%, PR: 0.93, 95% confidence interval [CI]: 0.62-1.41). For vaccine-targeted types there was some evidence of lower prevalence in the vaccinated (0.4%) compared to the unvaccinated (6.8%) group (PR: 0.06, 95%CI: 0.01-0.52). This difference remained after adjusting for sexual behavior (PR: 0.04, 95%CI: 0.00-0.42). Only four oral samples were positive for any HPV type, and all of these participants had received at least one dose of HPV vaccine at least 1 year before oral sexual debut.ConclusionThere is evidence of a lower prevalence of vaccine-targeted HPV types in the vagina of vaccinated girls from the first birth cohort eligible for school-based HPV vaccination in Norway; this was not the case when considering all HPV types or types not included in the quadrivalent HPV vaccine.

Project description:ImportanceSince 2000, the Lanzhou lamb rotavirus vaccine has been exclusively licensed in China for voluntary rotavirus gastroenteritis (RV-GE) prevention.ObjectiveTo evaluate the association of the Lanzhou lamb rotavirus vaccination with RV-GE among children in southern China.Design, setting, and participantsThis cross-sectional, ecological study was set in Guangzhou, China. Participants were infants possibly vaccinated (aged 2 months to 3 years) and the children ineligible for vaccination (aged ≥4 years). The study was conducted from May 1, 2007, to April 30, 2016, and the data analysis was conducted in July 2016.Main outcomes and measuresAnnual median age at onset of RV-GE and seasonal distribution of incidence. Cases of RV-GE in Guangzhou, China, diagnosed from May 1, 2007, to April 30, 2016, and reported to the National Information System for Disease Control and Prevention were examined. Poisson regression models were fitted among 32 452 children younger than 4 years and among 450 children who had been ineligible for vaccination, while controlling for secular trends, socioeconomic status, and meteorological factors. Logistic regression was used to assess the indirect effects provided by the vaccinated infants from 2009 to 2011 on unvaccinated infants aged 2 to 35 months based on a separate case-control data set.ResultsDuring 9 seasons, 119 705 patients with gastroenteritis were reported; 33 407 were confirmed for RV-GE (21 202 [63.5%] male, 32 022 [95.8%] aged <4 years, and 31 306 [93.8%] residing in urban districts). The median age at onset for all patients with RV-GE increased from 11 months during the 2007 season to 15 months during the 2015 season, and the onset, peak, and cessation of incidence were delayed. When citywide vaccination coverage in the prior 12 months was classified into high and low groups (≥8.36% vs <8.36%), the incidence rate ratio for the high coverage group decreased by 32.4% among children younger than 4 years (incidence rate ratio, 0.676; 95% CI, 0.659-0.693; P < .001). Among the children ineligible for vaccination, the incidence rate ratio in higher coverage periods was 0.790 (95% CI, 0.351-0.915; P < .001) compared with the lower coverage. Compared with districts with 14% or less vaccination coverage, the adjusted odds ratio for RV-GE among unvaccinated children younger than 3 years was 0.85 (95% CI, 0.73-0.99; P = .03) for districts with 15% to 19% of coverage, and 0.79 (95% CI, 0.67-0.93; P = .004) for districts with more than 20% of coverage.Conclusions and relevanceThis study provides evidence of the population health benefits of the Lanzhou lamb rotavirus vaccination in preventing RV-GE among children in China younger than 4 years, including herd effects.

Dataset Information

Substantial Decline in Prevalence of Vaccine-Type and Nonvaccine-Type Human Papillomavirus (HPV) in Vaccinated and Unvaccinated Girls 5 Years After Implementing HPV Vaccine in Norway.

Background

Methods

Results

Conclusions

Publications

Substantial Decline in Prevalence of Vaccine-Type and Nonvaccine-Type Human Papillomavirus (HPV) in Vaccinated and Unvaccinated Girls 5 Years After Implementing HPV Vaccine in Norway.

Similar Datasets

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