Real-world impact and effectiveness of the quadrivalent HPV vaccine: an updated systematic literature review.

INTRODUCTION: Human papillomavirus (HPV) infection, which poses significant disease burden, is decreasing following implementation of vaccination programs. Synthesized evidence on HPV vaccine real-world benefit was published in 2016. However, long-term impact of vaccination, and how vaccination programs influence infection rates and disease outcomes, requires further examination. AREAS COVERED: We systematically reviewed observational studies on HPV vaccination within MEDLINE, EMBASE, and Google Scholar from 2016 to 2020, involving 14 years of follow-up data. We identified 138 peer-reviewed publications reporting HPV vaccine impact or effectiveness. Outcomes of interest included rates of infection at different anatomical sites and incidence of several HPV-related disease endpoints. EXPERT OPINION: The expansion of HPV vaccination programs worldwide has led to a reduction in genital infection and significant decreases in incidence of HPV-related disease outcomes. Therefore, the WHO has set goals for the elimination of cervical cancer as a public health concern. To track progress toward this requires an understanding of the effectiveness of different vaccination initiatives. However, the impact on males, and potential benefit of gender-neutral vaccination programs have not been fully explored. To present an accurate commentary on the current outlook of vaccination and to help shape policy therefore requires a systematic review of available data.

Real-world impact and effectiveness assessment of the quadrivalent HPV vaccine: a systematic review of study designs and data sources.

INTRODUCTION: Vaccine effectiveness and impact studies are typically observational, generating evidence after vaccine launch in a real-world setting. For human papillomavirus (HPV) vaccination studies, the variety of data sources and methods used is pronounced. Careful selection of study design, data capture and analytical methods can mitigate potential bias in such studies. AREAS COVERED: We systematically reviewed the different study designs, methods, and data sources in published evidence (1/2007-3/2020), which assessed the quadrivalent HPV vaccine effectiveness and impact on cervical/cervicovaginal, anal, and oral HPV infections, anogenital warts, lesions in anus, cervix, oropharynx, penis, vagina or vulva, and recurrent respiratory papillomatosis. EXPERT OPINION: The rapid growth in access to real-world data allows global monitoring of effects of different public health interventions, including HPV vaccination programs. But the use of data which are not collected or organized to support research also underscore a need to develop robust methodology that provides insight of vaccine effects and consequences of different health policy decisions. To achieve the WHO elimination goal, we foresee a growing need to evaluate HPV vaccination programs globally. A critical appraisal summary of methodology used will provide timely guidance to researchers who want to initiate research activities in various settings.

The association of adverse events with bivalent human papilloma virus vaccination: A nationwide register-based cohort study in Finland.

BACKGROUND: A bivalent HPV vaccine (Cervarix®; HPV2, GlaxoSmithKline) was introduced into the Finnish national vaccination programme (NVP) in November 2013 for girls aged 11-13 years with a catch-up for 14-15 year-olds. We evaluated the association between HPV2 and selected autoimmune diseases and clinical syndromes by conducting a nation-wide retrospective register-based cohort study. METHODS: First life-time occurrences of the relevant ICD-10 codes in girls aged 11-15 years between Nov-2013 and Dec-2016 were obtained from the national hospital discharge register. Population denominators were obtained from the Population Information System and vaccination records from the National Vaccination Register. Registers were linked using unique personal identity codes. Association between HPV2 and 38 selected outcomes were studied using Cox regression, with age as the main time-scale and the first vaccination dose as the time-dependent exposure. The hazard ratios (HR) with 95%CI were assessed according to the time since exposure (entire follow-up, 0-180/181-365/>365 days). RESULTS: Of 240 605 girls eligible for HPV2 vaccination, 134 615 (56%) were vaccinated. After adjustment for geographical area (6 hospital districts), country of origin (Finnish-born/not) and number of hospital contacts from 9 through 10 years of age, HRs ranged from 0.34 (95%CI 0.11-1.05) to 8.37 (95%CI 0.85-82.54) and HPV2 vaccination was not statistically significantly associated with a higher risk of any outcome during the entire follow-up. CONCLUSIONS: This study found no significantly increased risk for the selected outcomes after the HPV vaccination in girls 11-15 years of age. These results provide valid evidence to counterbalance public scepticism, fears of adverse events and possible opposition to HPV vaccination and consequently can contribute to increase HPV vaccination coverage in Finland as well as elsewhere.

Interhospital Comparison of Surgical Site Infection Rates in Orthopedic Surgery.

OBJECTIVE To investigate whether comparison by deep or adjusted deep surgical site infection (SSI) rates in orthopedic surgeries are a better basis for feedback to Finnish hospitals than overall SSI rates DESIGN Retrospective cohort study SETTING Hospitals conducting surveillance of hip arthroplasties (HPROs) and knee arthroplasties (KPROs) in the Finnish Hospital Infection Program METHODS We analyzed surveillance data for 73,227 HPROs and 56,860 KPROs performed in 18 hospitals during 1999-2014. For each hospital, the overall, deep, and adjusted deep SSI rates with 95% confidence intervals (CIs) were calculated, and the hospital ranks were simulated in the Bayesian framework. Adjustments were performed using relevant patient and hospital characteristics. The correlation between the median expected hospital ranks in overall versus deep SSI rates and deep vs adjusted deep SSI rates were assessed using Spearman's correlation coefficient ρ. RESULTS For HPRO, the overall SSI rates ranged from 0.92 to 6.83, the deep SSI rates ranged from 0.34 to 1.86, and the adjusted deep hospital-specific SSI rates ranged from 0.37 to 1.85. For KPRO, the overall SSI rates ranged from 0.71 to 5.03, the deep SSI rates ranged from 0.42 to 1.60, and the adjusted deep hospital-specific SSI rates ranged from 0.56 to 1.55. For both procedures, the 95% CIs of the rates between hospitals largely overlapped; only single outliers were detected. Hospital rank did not correlate between overall and deep SSI rates (HPRO, ρ=0.03; KPRO, ρ=0.40), but a correlation was observed in hospital rank for deep and adjusted deep SSI rates (HPRO, ρ=0.85; KPRO, ρ=0.94). CONCLUSION Deep SSI rates may be a better tool for interhospital comparisons than overall SSI rates. Although the adjustment could lead to fairer hospital ranking, it is not always necessary for feedback. Infect Control Hosp Epidemiol 2017;38:423-429.