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Bollaerts K, Wyndham-Thomas C, Miller E, Izurieta HS, Black S, Andrews N, Rubbrecht M, Van Heuverswyn F, Neels P. The role of real-world evidence for regulatory and public health decision-making for Accelerated Vaccine Deployment- a meeting report. Biologicals 2024; 85:101750. [PMID: 38360428 DOI: 10.1016/j.biologicals.2024.101750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 02/04/2024] [Indexed: 02/17/2024] Open
Abstract
The COVID-19 pandemic underscored the need for rapid evidence generation to inform public health decisions beyond the limitations of conventional clinical trials. This report summarises presentations and discussions from a conference on the role of Real-World Evidence (RWE) in expediting vaccine deployment. Attended by regulatory bodies, public health entities, and industry experts, the gathering was a collaborative exchange of experiences and recommendations for leveraging RWE for vaccine deployment. RWE proved instrumental in refining decision-making processes to optimise dosing regimens, enhance guidance on target populations, and steer vaccination strategies against emerging variants. Participants felt that RWE was successfully integrated into lifecycle management, encompassing boosters and safety considerations. However, challenges emerged, prompting a call for improvements in data quality, standardisation, and availability, acknowledging the variability and potential inaccuracies in data across diverse healthcare systems. Regulatory transparency should also be prioritised to foster public trust, and improved collaborations with governments are needed to streamline data collection and navigate data privacy regulations. Moreover, building and sustaining resources, expertise, and infrastructure in LMICs emerged as imperative for RWE-generating capabilities. Continued stakeholder collaboration and securing adequate funding emerged as vital pillars for advancing the use of RWE in shaping responsive and effective public health strategies.
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Affiliation(s)
| | | | - Elizabeth Miller
- London School of Hygiene and Tropical Medicine (LSHTM), United Kingdom
| | | | - Steve Black
- Global Vaccine Data Network (GVDN), New Zealand
| | - Nick Andrews
- UK Health Security Agency (UKHSA), United Kingdom
| | | | | | - Pieter Neels
- International Alliance of Biological Standardization (IABS-EU), Belgium.
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Meeraus W, de Munter L, Gray CM, Dwivedi A, Wyndham-Thomas C, Ouwens M, Hartig-Merkel W, Drikite L, Rebry G, Carmona A, Stuurman AL, Chi Nguyen TY, Mena G, Mira-Iglesias A, Icardi G, Otero-Romero S, Baumgartner S, Martin C, Taylor S, Bollaerts K. Protection against COVID-19 hospitalisation conferred by primary-series vaccination with AZD1222 in non-boosted individuals: first vaccine effectiveness results of the European COVIDRIVE study and meta-regression analysis. Lancet Reg Health Eur 2023; 31:100675. [PMID: 37547274 PMCID: PMC10398604 DOI: 10.1016/j.lanepe.2023.100675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/30/2023] [Accepted: 06/14/2023] [Indexed: 08/08/2023]
Abstract
Background Vaccine effectiveness (VE) studies with long-term follow-up are needed to understand durability of protection against severe COVID-19 outcomes conferred by primary-series vaccination in individuals not receiving boosters. COVIDRIVE is a European public-private partnership evaluating brand-specific vaccine effectiveness (VE). We report a prespecified interim analysis of primary-series AZD1222 (ChAdOx1 nCoV-19) VE. Methods Seven Study Contributors in Europe collected data on individuals aged ≥18 years who were hospitalised with severe acute respiratory infection (June 1st, 2021-September 5th, 2022) and eligible for COVID-19 vaccination prior to hospitalisation. In this test-negative case-control study, individuals were defined as test-positive cases or test-negative controls (SARS-CoV-2 RT-PCR) and were either fully vaccinated (two AZD1222 doses, 4-12 weeks apart, completed ≥14 days prior to symptom onset; no booster doses) or unvaccinated (no COVID-19 vaccine prior to hospitalisation). The primary objective was to estimate AZD1222 VE against COVID-19 hospitalisation. A literature review and meta-regression were conducted to contextualise findings on durability of protection. Findings 761 individuals were included during the 15-month analysis period. Overall AZD1222 VE estimate was 72.8% (95% CI, 53.4-84.1). VE was 93.8% (48.6-99.3) in participants who received second AZD1222 doses ≤8 weeks prior to hospitalisation, with spline-based VE estimates demonstrating protection (VE ≥ 50%) 30 weeks post-second dose. Meta-regression analysis (data from seven publications) showed consistent results, with ≥80% protection against COVID-19 hospitalisation through ∼43 weeks post-second dose, with some degree of waning. Interpretation Primary-series AZD1222 vaccination confers protection against COVID-19 hospitalisation with enduring levels of VE through ≥6 months. Funding AstraZeneca.
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Affiliation(s)
- Wilhelmine Meeraus
- Medical Evidence, Vaccines & Immune Therapies, AstraZeneca, Cambridge, UK
| | | | - Christen M. Gray
- Real World Science, BioPharmaceuticals Medical, AstraZeneca, Cambridge, UK
| | | | | | - Mario Ouwens
- Medical and Payor Statistics, BioPharmaceutical Business Unit, AstraZeneca, Mölndal, Sweden
| | | | - Laura Drikite
- P95 Pharmacovigilance and Epidemiology, Leuven, Belgium
| | - Griet Rebry
- P95 Pharmacovigilance and Epidemiology, Leuven, Belgium
| | - Antonio Carmona
- Vaccine Research Department, Fundación para el Fomento de la Investigación Sanitaria y Biomédica (FISABIO) de la Comunitat Valenciana, Salud Pública, Valencia, Spain
- Biomedical Research Consortium of Epidemiology and Public Health (CIBER-ESP), Instituto de Salud Carlos III, Madrid, Spain
| | - Anke L. Stuurman
- Medical Evidence, Vaccines & Immune Therapies, AstraZeneca, Cambridge, UK
- P95 Pharmacovigilance and Epidemiology, Leuven, Belgium
| | - Thi Yen Chi Nguyen
- Medical Evidence, Vaccines & Immune Therapies, AstraZeneca, Cambridge, UK
- P95 Pharmacovigilance and Epidemiology, Leuven, Belgium
| | - Guillermo Mena
- Preventive Medicine Department - Germans Trias i Pujol University Hospital, Badalona, Spain
- Autonomous University of Barcelona, Bellaterra, Spain
- Germans Trias I Pujol Research Institute (IGTP), Badalona, Spain
| | - Ainara Mira-Iglesias
- Vaccine Research Department, Fundación para el Fomento de la Investigación Sanitaria y Biomédica (FISABIO) de la Comunitat Valenciana, Salud Pública, Valencia, Spain
- Biomedical Research Consortium of Epidemiology and Public Health (CIBER-ESP), Instituto de Salud Carlos III, Madrid, Spain
| | - Giancarlo Icardi
- Interuniversity Research Centre on Influenza and Other Transmissible Infections (CIRI-IT), Genoa, Italy
- Department of Health Sciences, University of Genoa, Italy
| | - Susana Otero-Romero
- Servicio de Medicina Preventiva y Epidemiología, Hospital Universitari Vall d'Hebron, Vall d'Hebron Barcelona Campus Hospitalari, Barcelona, Spain
| | - Sebastian Baumgartner
- Fourth Medical Department with Infectious Diseases and Tropical Medicine, Klinik Favoriten/Kaiser-Franz-Josef Hospital, Vienna, Austria
| | - Charlotte Martin
- Infectious Diseases Department, Centre Hospitalier Universitaire Saint-Pierre, Brussels, Belgium
| | - Sylvia Taylor
- Medical Evidence, Vaccines & Immune Therapies, AstraZeneca, Cambridge, UK
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Biccler J, Bollaerts K, Vora P, Sole E, Rodriguez LAG, Lanas A, Langley RE, Gabarró MS. Public health impact of low-dose aspirin on colorectal cancer, cardiovascular disease and safety in the UK - Results from micro-simulation model. Int J Cardiol Heart Vasc 2021; 36:100851. [PMID: 34401469 PMCID: PMC8350404 DOI: 10.1016/j.ijcha.2021.100851] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 07/26/2021] [Indexed: 12/29/2022]
Abstract
Background Low-dose aspirin therapy reduces the risk of cardiovascular disease and may have a positive effect on the prevention of colorectal cancer. We evaluated the population-level expected effect of regular low-dose aspirin use on cardiovascular disease (CVD), colorectal cancer (CRC), gastrointestinal bleeding, symptomatic peptic ulcers, and intracranial hemorrhage, using a microsimulation study design. Methods We used individual-level state transition modeling to assess the impact of aspirin in populations aged 50–59 or 60–69 years old indicated for low-dose aspirin usage for primary or secondary CVD prevention. Model parameters were based on data from governmental agencies from the UK or recent publications. Results In the 50–59 years cohort, a decrease in incidence rates (IRs per 100 000 person years) of non-fatal CVD (-203 and −794) and fatal CVD (-97 and-381) was reported in the primary and secondary CVD prevention setting, respectively. The IR reduction of CRC (-96 and −93) was similar for primary and secondary CVD prevention. The IR increase of non-fatal (116 and 119) and fatal safety events (6 and 6) was similar for primary and secondary CVD prevention. Similar results were obtained for the 60–69 years cohort. Conclusions The decrease in fatal CVD and CRC events was larger than the increase in fatal safety events and this difference was more pronounced when low-dose aspirin was used for secondary compared to primary CVD prevention. These results provide a comprehensive image of the expected effect of regular low-dose aspirin therapy in a UK population indicated to use aspirin for CVD prevention.
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Affiliation(s)
- Jorne Biccler
- P95 Epidemiology and Pharmacovigilance, Leuven, Belgium
| | | | - Pareen Vora
- Bayer AG, Epidemiology, Integrated Evidence Generation, Berlin, Germany
| | - Elodie Sole
- P95 Epidemiology and Pharmacovigilance, Leuven, Belgium
| | | | - Angel Lanas
- Servicio de Aparato Digestivo, Hospital Clínico, University of Zaragoza, Zaragoza, Spain.,CIBERehd. IIS Aragón, Zaragoza, Spain
| | - Ruth E Langley
- MRC Clinical Trials Unit, University College London, London, United Kingdom
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Bollaerts K, Fletcher MA, Suaya JA, Hanquet G, Baay M, Gessner BD. Vaccine-Preventable Disease Incidence Based on Clinically, Radiologically and Etiologically Confirmed Outcomes: Systematic Literature Review and Re-analysis of Pneumococcal Conjugate Vaccine Efficacy Trials. Clin Infect Dis 2021; 74:1362-1371. [PMID: 34313721 PMCID: PMC9049266 DOI: 10.1093/cid/ciab649] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Indexed: 11/14/2022] Open
Abstract
Background Vaccine regulatory decision making is based on vaccine efficacy against etiologically confirmed outcomes, which may underestimate the preventable disease burden. To quantify this underestimation, we compared vaccine-preventable disease incidence (VPDI) of clinically defined outcomes with radiologically/etiologically confirmed outcomes. Methods We performed a systematic review of efficacy trials for several vaccines (1997–2019) and report results for pneumococcal conjugate vaccines. Data were extracted for outcomes within a clinical syndrome, organized from most sensitive to most specific. VPDI was determined for each outcome, and VPDI ratios were calculated, with a clinically defined outcome (numerator) and a radiologically/etiologically confirmed outcome (denominator). Results Among 9 studies, we calculated 27 VPDI ratios; 24 had a value >1. Among children, VPDI ratios for clinically defined versus vaccine serotype otitis media were 0.6 (95% CI not calculable), 2.1 (1.5–3.0), and 3.7 (1.0–10.2); the VPDI ratios comparing clinically defined with radiologically confirmed pneumonia ranged from not calculable to 2.7 (1.2–10.4); the VPDI ratio comparing clinically suspected invasive pneumococcal disease (IPD) with laboratory-confirmed IPD was 3.8 (95% CI not calculable). Among adults, the ratio comparing clinically defined with radiologically confirmed pneumonia was 1.9 (−6.0 to 9.1) and with vaccine serotype–confirmed pneumonia was 2.9 (.5–7.8). Conclusions While there is substantial uncertainty around individual point estimates, there is a consistent trend in VPDI ratios, most commonly showing under-ascertainment of 1.5- to 4-fold, indicating that use of clinically defined outcomes is likely to provide a more accurate estimate of a pneumococcal conjugate vaccine’s public health value.
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Affiliation(s)
| | - Mark A Fletcher
- Pfizer Inc., Emerging Markets Medical Affairs, Paris, France
| | - Jose A Suaya
- Pfizer Inc., Vaccines Medical Development & Scientific/Clinical Affairs, New York, NY, United States of America
| | | | - Marc Baay
- P95 Epidemiology and Pharmacovigilance, Leuven, Belgium
| | - Bradford D Gessner
- Pfizer Inc., Scientific Affairs, Collegeville, PA, United States of America
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Méroc E, Fröberg J, Almasi T, Winje BA, Orrico-Sánchez A, Steens A, McDonald SA, Bollaerts K, Knol MJ. European data sources for computing burden of (potential) vaccine-preventable diseases in ageing adults. BMC Infect Dis 2021; 21:345. [PMID: 33849461 PMCID: PMC8042717 DOI: 10.1186/s12879-021-06017-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 03/24/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To guide decision-making on immunisation programmes for ageing adults in Europe, one of the aims of the Vaccines and InfecTious diseases in the Ageing popuLation (IMI2-VITAL) project is to assess the burden of disease (BoD) of (potentially) vaccine-preventable diseases ((P)VPD). We aimed to identify the available data sources to calculate the BoD of (P)VPD in participating VITAL countries and to pinpoint data gaps. Based on epidemiological criteria and vaccine availability, we prioritized (P) VPD caused by Extra-intestinal pathogenic Escherichia coli (ExPEC), norovirus, respiratory syncytial virus, Staphylococcus aureus, and pneumococcal pneumonia. METHODS We conducted a survey on available data (e.g. incidence, mortality, disability-adjusted life years (DALY), quality-adjusted life years (QALY), sequelae, antimicrobial resistance (AMR), etc.) among national experts from European countries, and carried out five pathogen-specific literature reviews by searching MEDLINE for peer-reviewed publications published between 2009 and 2019. RESULTS Morbidity and mortality data were generally available for all five diseases, while summary BoD estimates were mostly lacking. Available data were not always stratified by age and risk group, which is especially important when calculating BoD for ageing adults. AMR data were available in several countries for S. aureus and ExPEC. CONCLUSION This study provides an exhaustive overview of the available data sources and data gaps for the estimation of BoD of five (P) VPD in ageing adults in the EU/EAA, which is useful to guide pathogen-specific BoD studies and contribute to calculation of (P)VPDs BoD.
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Affiliation(s)
- Estelle Méroc
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan 1, 3001, Leuven, Belgium.
| | - Janeri Fröberg
- Radboud University Medical Center, Radboud Institute for Molecular Life Sciences, Laboratory of Medical Immunology, Section Paediatric Infectious Diseases, Geert Grooteplein 21, 6525 EZ, Nijmegen, the Netherlands
| | - Timea Almasi
- Syreon Research Institute, Mexikoi str. 65/A, Budapest, 1142, Hungary
| | - Brita Askeland Winje
- Department of Infection Control and Vaccine, Norwegian Institute of Public Health, PO Box 222, Skøyen, 0213, Oslo, Norway
| | - Alejandro Orrico-Sánchez
- Vaccines Research Unit, FISABIO (the Valencia Foundation for the Promotion of Health and Biomedical Research), Av. Catalunya, 21, 46020, Valencia, Spain
| | - Anneke Steens
- Department of Infection Control and Vaccine, Norwegian Institute of Public Health, PO Box 222, Skøyen, 0213, Oslo, Norway
| | - Scott A McDonald
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA, Bilthoven, the Netherlands
| | - Kaatje Bollaerts
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan 1, 3001, Leuven, Belgium
| | - Mirjam J Knol
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA, Bilthoven, the Netherlands
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Bollaerts K, de Smedt T, McGee C, Emborg HD, Villa M, Alexandridou M, Duarte-Salles T, Gini R, Bartolini C, de Lusignan S, Tin Tin Htar M, Titievsky L, Sturkenboom M, Bauchau V. ADVANCE: Towards near real-time monitoring of vaccination coverage, benefits and risks using European electronic health record databases. Vaccine 2020; 38 Suppl 2:B76-B83. [DOI: 10.1016/j.vaccine.2019.08.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 08/01/2019] [Accepted: 08/07/2019] [Indexed: 12/15/2022]
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Hall GC, Lanes S, Bollaerts K, Zhou X, Ferreira G, Gini R. Outcome misclassification: Impact, usual practice in pharmacoepidemiology database studies and an online aid to correct biased estimates of risk ratio or cumulative incidence. Pharmacoepidemiol Drug Saf 2020; 29:1450-1455. [PMID: 32860317 DOI: 10.1002/pds.5109] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 07/09/2020] [Accepted: 07/30/2020] [Indexed: 11/06/2022]
Abstract
PURPOSE It is well documented that outcome misclassification can bias a point estimate. We aimed to understand current practice in addressing this bias in pharmacoepidemiology database studies and to develop an open source application (app) from existing methodology to demonstrate the impact and mechanism of this bias on results. METHODS Studies of an exposure and a clinical outcome were selected from all Pharmacoepidemiology and Drug Safety publications during 2017 and any reference to outcome misclassification described. An app to correct risk ratio (RR) and cumulative incidence for outcome misclassification was developed from a published methodology and used to demonstrate the impact of correction on point estimates. RESULTS Eight (19%) of 43 papers selected reported estimates of outcome ascertainment accuracy with positive predictive value (PPV) the most commonly reported measure (7 of 8 studies). Three studies (7%) corrected for the bias, 1 by exposure strata, and 5 (12%) restricted analyses to confirmed cases. The app (app http://apps.p-95.com/ISPE/) uses values of PPV and sensitivity (or a range of possible values) in each exposure strata and returns corrected point estimates and confidence intervals. The app demonstrates that small differences between comparison groups in PPV or sensitivity can introduce bias even when accuracy estimates are high. CONCLUSIONS Outcome misclassification is not usually corrected in pharmacoepidemiology database studies although correction methods using routinely measured indices are available. Error indices are needed for each comparison group to correct RR estimates for these errors. The app should encourage understanding of this bias and increase adjustment.
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Affiliation(s)
| | | | | | - Xiaofeng Zhou
- Global Medical Epidemiology, Pfizer Inc., New York, US
| | | | - Rosa Gini
- Osservatorio di Epidemiologia, Agenzia Regionale di Sanità Della Toscana, Florence, Italy
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Van Baarle D, Bollaerts K, Del Giudice G, Lockhart S, Luxemburger C, Postma MJ, Timen A, Standaert B. Preventing infectious diseases for healthy ageing: The VITAL public-private partnership project. Vaccine 2020; 38:5896-5904. [PMID: 32713682 PMCID: PMC7378501 DOI: 10.1016/j.vaccine.2020.07.005] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 11/16/2022]
Abstract
Prevention of infectious diseases through immunisation of the growing ageing adult population is essential to improve healthy ageing. However, many licenced and recommended vaccines for this age group show signs of waning of the protective effect due to declining immune responses (immuno-senescence) and decreasing vaccine uptake. Today's major challenge is to improve vaccine effectiveness and uptake and to deploy efficient vaccination strategies for this age group. The Vaccines and InfecTious diseases in the Ageing popuLation (VITAL) project, with partners from 17 academic & research groups and public institutes as well as seven industry collaborators, aims to address this challenge. The ambition is to provide evidence-based knowledge to local decision makers. Using a holistic and multidisciplinary approach and novel analytical methods, VITAL will provide tools that allow the development of targeted immunisation programs for ageing adults in European countries. The project is based on four pillars focussing on the assessment of the burden of vaccine-preventable diseases in ageing adults, the dissection of the mechanisms underlying immuno-senescence, the analysis of the clinical and economic public health impact of vaccination strategies and the development of educational resources for healthcare professionals. By the end of the project, a clear, detailed, and integrated program should be available for implementing a consistent, affordable, and sustainable vaccination strategy for ageing adults with regular evaluations of its impact over time.
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Affiliation(s)
- Debbie Van Baarle
- Center for Infectious Disease Prevention, National Institute for Public Health and the Environment, Bilthoven, the Netherlands; Center for Translational Immunology, University Medical Center Utrecht, University of Utrecht, Utrecht, the Netherlands.
| | | | | | | | | | | | - Aura Timen
- Center for Infectious Disease Prevention, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
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Stuurman AL, Bollaerts K, Alexandridou M, Biccler J, Díez Domingo J, Nohynek H, Rizzo C, Turunen T, Riera-Montes M. Vaccine effectiveness against laboratory-confirmed influenza in Europe - Results from the DRIVE network during season 2018/19. Vaccine 2020; 38:6455-6463. [PMID: 32778474 DOI: 10.1016/j.vaccine.2020.07.063] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 07/20/2020] [Accepted: 07/28/2020] [Indexed: 10/23/2022]
Abstract
The DRIVE project aims to establish a sustainable network to estimate brand-specific influenza vaccine effectiveness (IVE) annually. DRIVE is a public-private partnership launched in response to EMA guidance that requires effectiveness evaluation from manufacturers for all individual influenza vaccine brands every season. IVE studies are conducted by public partners in DRIVE. Private partners (vaccine manufacturers from the European Federation of Pharmaceutical Industries and Association (EFPIA)) provide written feedback moderated by an independent scientific committee. Test-negative design (TND) case-control studies (4 in primary care and five in hospital) were conducted in six countries in Europe during the 2018/19 season. Site-specific confounder-adjusted vaccine effectiveness (VE) estimates for any vaccine exposure were calculated by age group (<18 years (y), 18-64y and 65 + y) and pooled by setting (primary care, hospital) through random effects meta-analysis. In addition, one population-based cohort study was conducted in Finland. TND studies included 3339 cases and 6012 controls; seven vaccine brands were reported. For ages 65 + y, pooled VE against any influenza strain was estimated at 27% (95%CI 6-44) in hospital setting. Sample size was insufficient for meaningful IVE estimates in other age groups, in the primary care setting, or by vaccine brand. The population-based cohort study included 274,077 vaccinated and 494,337 unvaccinated person-years, two vaccine brands were reported. Brand-specific IVE was estimated for Fluenz Tetra (36% [95%CI 24-45]) for ages 2-6y, Vaxigrip Tetra (54% [43-62]) for ages 6 months to 6y, and Vaxigrip Tetra (30% [25-35]) for ages 65 + y. The results presented are from the second influenza season covered by the DRIVE network. While sample size from the pooled TND studies was still too low for precise (brand-specific) IVE estimates, the network has approximately doubled in size compared to the pilot season. Taking measures to increase sample size is an important focus of DRIVE for the coming years.
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Affiliation(s)
| | | | | | - Jorne Biccler
- P95 Pharmacovigilance and Epidemiology, Leuven, Belgium
| | | | - Hanna Nohynek
- Finnish Institute for Health and Welfare, Helsinki, Finland
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Tin Tin Htar M, de Ridder M, Braeye T, Correa A, McGee C, de Lusignan S, Duarte-Salles T, Huerta-Alvarez C, Martín-Merino E, Tramontan L, Danieli G, Picelli G, van der Maas N, Berencsi K, Arnheim-Dahlström L, Heininger U, Emborg HD, Weibel D, Bollaerts K, Sturkenboom M. Advance system testing: Vaccine benefit studies using multi-country electronic health data - The example of pertussis vaccination. Vaccine 2019; 38 Suppl 2:B31-B37. [PMID: 31677949 DOI: 10.1016/j.vaccine.2019.08.078] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 08/21/2019] [Accepted: 08/29/2019] [Indexed: 12/01/2022]
Abstract
The Accelerated Development of VAccine benefit-risk Collaboration in Europe (ADVANCE), a public-private consortium, implemented and tested a distributed network system for the generation of evidence on the benefits-risks of marketed vaccines in Europe. We tested the system by estimating the incidence rate (IR) of pertussis and pertussis-related complications in children vaccinated with acellular (aP) and whole-cell (wP) pertussis vaccine. Data from seven electronic databases from four countries (Denmark: AUH and SSI, Spain: SIDIAP and BIFAP, UK: THIN and RCGP RSC and Italy: Pedianet) were included in a retrospective cohort analysis. Exposure was defined as any pertussis vaccination (aP or wP). The follow-up time started 14 days after the first dose. Children who had received any pertussis vaccine from January 1990 to December 2015 were included (those who switched type, or had unknown type were excluded). The outcomes of interest were confirmed or suspected pertussis and pertussis-related pneumonia and generalised convulsions within one month of pertussis diagnosis and death within three months of pertussis diagnosis. The cohort comprised 2,886,367 children ≤5 years of age. Data on wP and aP vaccination were available in three and seven databases, respectively. The IRs (per 100,000 person-years) for pertussis varied largely and ranged between 0.15 (95% CI: 0.12; 0.19) and 1.15 (95% CI: 1.07; 1.23), and the trends over time was consistent with those observed from national surveillance databases for confirmed pertussis. The pertussis IRs decreased as the number of wP and aP vaccine doses increased. Pertussis-related complications were rare (89 pneumonia, 7 generalised convulsions and no deaths) and their relative risk (vs. non-pertussis) could not be reliably estimated. The study demonstrated the feasibility of the ADVANCE system to estimate the change in pertussis IRs following pertussis vaccination. Larger sample sizes would provide additional power to compare the risk for complications between children with and without pertussis. The feasibility of vaccine-type specific effectiveness studies may be considered in the future.
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Affiliation(s)
- Myint Tin Tin Htar
- Clinical Epidemiology, Pfizer, 23-25 Avenue du Dr Lannelongue, 75014 Paris, France.
| | - Maria de Ridder
- Erasmus University Medical Center, PO Box 2014, 3000 CA Rotterdam, the Netherlands.
| | - Toon Braeye
- Sciensano, Rue Juliette Wytsmanstraat 14, 1050 Brussels, Belgium.
| | - Ana Correa
- University of Surrey, Guildford, Surrey GU2 7XH, UK
| | - Chris McGee
- University of Surrey, Guildford, Surrey GU2 7XH, UK; Royal College of General Practitioners Research and Surveillance Centre, 30 Euston Square, London NW1 2FB, UK.
| | - Simon de Lusignan
- University of Surrey, Guildford, Surrey GU2 7XH, UK; Royal College of General Practitioners Research and Surveillance Centre, 30 Euston Square, London NW1 2FB, UK.
| | - Talita Duarte-Salles
- Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.
| | - Consuelo Huerta-Alvarez
- Division of Pharmacoepidemiology and Pharmacovigilance, Spanish Agency of Medicines and Medical Devices (AEMPS), Madrid, Spain.
| | - Elisa Martín-Merino
- Division of Pharmacoepidemiology and Pharmacovigilance, Spanish Agency of Medicines and Medical Devices (AEMPS), Madrid, Spain.
| | - Lara Tramontan
- PEDIANET, Padova, Italy; Consorzio Arsenal.IT, Veneto Region, Italy.
| | - Giorgia Danieli
- PEDIANET, Padova, Italy; Consorzio Arsenal.IT, Veneto Region, Italy.
| | | | - Nicoline van der Maas
- National Institute for Public Health and the Environment (RIVM), Bilthoven, Netherlands.
| | - Klara Berencsi
- Aarhus University Hospital, Olof Palmes Alle 43-45, DK-8200 Aarhus, Denmark.
| | | | - Ulrich Heininger
- University of Basel Children's Hospital, PO Box, CH 4033 Basel, Switzerland; University of Basel, Basel, Switzerland.
| | | | - Daniel Weibel
- Erasmus University Medical Center, PO Box 2014, 3000 CA Rotterdam, the Netherlands; VACCINE.GRID, Spitalstrasse 33, Basel, Switzerland.
| | | | - Miriam Sturkenboom
- VACCINE.GRID, Spitalstrasse 33, Basel, Switzerland; P95, Epidemiology and Pharmacovigilance, Leuven, Belgium; Julius Global Health, University Medical Center Utrecht, Heidelberglaan 100, the Netherlands.
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Bollaerts K, Ledent E, de Smedt T, Weibel D, Emborg HD, Danieli G, Duarte-Salles T, Huerta-Alvarez C, Martín-Merino E, Picelli G, Tramontan L, Sturkenboom M, Bauchau V. ADVANCE system testing: Benefit-risk analysis of a marketed vaccine using multi-criteria decision analysis and individual-level state transition modelling. Vaccine 2019; 38 Suppl 2:B65-B75. [PMID: 31677947 DOI: 10.1016/j.vaccine.2019.09.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 09/02/2019] [Accepted: 09/09/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines using electronic health record (eHR) databases in Europe. Proof-of-concept studies were designed to assess the proposed processes and system for generating the required evidence to perform B/R assessment and near-real time monitoring of vaccines. We aimed to test B/R methodologies for vaccines, using the comparison of the B/R profiles of whole-cell (wP) and acellular pertussis (aP) vaccine formulations in children as an example. METHODS We used multi-criteria decision analysis (MCDA) to structure the B/R assessment combined with individual-level state transition modelling to build the B/R effects table. In the state transition model, we simulated the number of events in two hypothetical cohorts of 1 million children followed from first pertussis dose till pre-school-entry booster (or six years of age, whichever occurred first), with one cohort receiving wP, and the other aP. The benefits were reductions in pertussis incidence and complications. The risks were increased incidences of febrile convulsions, fever, hypotonic-hyporesponsive episodes, injection-site reactions and persistent crying. Most model parameters were informed by estimates (coverage, background incidences, relative risks) from eHR databases from Denmark (SSI), Spain (BIFAP and SIDIAP), Italy (Pedianet) and the UK (RCGP-RSC and THIN). Preferences were elicited from clinical and epidemiological experts. RESULTS Using state transition modelling to build the B/R effects table facilitated the comparison of different vaccine effects (e.g. immediate vaccine risks vs long-term vaccine benefits). Estimates from eHR databases could be used to inform the simulation model. The model results could be easily combined with preference weights to obtain B/R scores. CONCLUSION Existing B/R methodology, modelling and estimates from eHR databases can be successfully used for B/R assessment of vaccines.
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Affiliation(s)
- Kaatje Bollaerts
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan, 1 3001 Heverlee, Belgium.
| | | | - Tom de Smedt
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan, 1 3001 Heverlee, Belgium.
| | - Daniel Weibel
- Erasmus University Medical Center, Post box 2040, 3000 CA Rotterdam, the Netherlands; VACCINE.GRID, Spitalstrasse 33, Basel, Switzerland.
| | | | - Giorgia Danieli
- Epidemiological Information for Clinical Research from an Italian Network of Family Paediatricians (PEDIANET), Padova, Italy
| | - Talita Duarte-Salles
- Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.
| | - Consuelo Huerta-Alvarez
- Base de Datos Para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP), Spanish Agency of Medicines and Medical Devices (AEMPS), Madrid, Spain.
| | - Elisa Martín-Merino
- Base de Datos Para la Investigación Farmacoepidemiológica en Atención Primaria (BIFAP), Spanish Agency of Medicines and Medical Devices (AEMPS), Madrid, Spain.
| | - Gino Picelli
- Epidemiological Information for Clinical Research from an Italian Network of Family Paediatricians (PEDIANET), Padova, Italy.
| | - Lara Tramontan
- Epidemiological Information for Clinical Research from an Italian Network of Family Paediatricians (PEDIANET), Padova, Italy.
| | - Miriam Sturkenboom
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan, 1 3001 Heverlee, Belgium; VACCINE.GRID, Spitalstrasse 33, Basel, Switzerland; Julius Global Health, University Medical Center Utrecht, Heidelberglaan 100, the Netherlands.
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12
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Gini R, Dodd CN, Bollaerts K, Bartolini C, Roberto G, Huerta-Alvarez C, Martín-Merino E, Duarte-Salles T, Picelli G, Tramontan L, Danieli G, Correa A, McGee C, Becker BFH, Switzer C, Gandhi-Banga S, Bauwens J, van der Maas NAT, Spiteri G, Sdona E, Weibel D, Sturkenboom M. Quantifying outcome misclassification in multi-database studies: The case study of pertussis in the ADVANCE project. Vaccine 2019; 38 Suppl 2:B56-B64. [PMID: 31677950 DOI: 10.1016/j.vaccine.2019.07.045] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Revised: 05/28/2019] [Accepted: 07/10/2019] [Indexed: 10/25/2022]
Abstract
BACKGROUND The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines using European healthcare databases. Event misclassification can result in biased estimates. Using different algorithms for identifying cases of Bordetella pertussis (BorPer) infection as a test case, we aimed to describe a strategy to quantify event misclassification, when manual chart review is not feasible. METHODS Four participating databases retrieved data from primary care (PC) setting: BIFAP: (Spain), THIN and RCGP RSC (UK) and PEDIANET (Italy); SIDIAP (Spain) retrieved data from both PC and hospital settings. BorPer algorithms were defined by healthcare setting, data domain (diagnoses, drugs, or laboratory tests) and concept sets (specific or unspecified pertussis). Algorithm- and database-specific BorPer incidence rates (IRs) were estimated in children aged 0-14 years enrolled in 2012 and 2014 and followed up until the end of each calendar year and compared with IRs of confirmed pertussis from the ECDC surveillance system (TESSy). Novel formulas were used to approximate validity indices, based on a small set of assumptions. They were applied to approximately estimate positive predictive value (PPV) and sensitivity in SIDIAP. RESULTS The number of cases and the estimated BorPer IRs per 100,000 person-years in PC, using data representing 3,173,268 person-years, were 0 (IR = 0.0), 21 (IR = 4.3), 21 (IR = 5.1), 79 (IR = 5.7), and 2 (IR = 2.3) in BIFAP, SIDIAP, THIN, RCGP RSC and PEDIANET respectively. The IRs for combined specific/unspecified pertussis were higher than TESSy, suggesting that some false positives had been included. In SIDIAP the estimated IR was 45.0 when discharge diagnoses were included. The sensitivity and PPV of combined PC specific and unspecific diagnoses for BorPer cases in SIDIAP were approximately 85% and 72%, respectively. CONCLUSION Retrieving BorPer cases using only specific concepts has low sensitivity in PC databases, while including cases retrieved by unspecified concepts introduces false positives, which were approximately estimated to be 28% in one database. The share of cases that cannot be retrieved from a PC database because they are only seen in hospital was approximately estimated to be 15% in one database. This study demonstrated that quantifying the impact of different event-finding algorithms across databases and benchmarking with disease surveillance data can provide approximate estimates of algorithm validity.
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Affiliation(s)
- Rosa Gini
- Agenzia regionale di sanità della Toscana, Osservatorio di epidemiologia, Florence, Italy.
| | - Caitlin N Dodd
- Erasmus University Medical Center, Post Box 2040, 3000 CA Rotterdam, Netherlands; Julius Global Health, University Medical Center, Utrecht, Heidelberglaan 100, the Netherlands
| | - Kaatje Bollaerts
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan 1, 3001 Heverlee, Belgium.
| | - Claudia Bartolini
- Agenzia regionale di sanità della Toscana, Osservatorio di epidemiologia, Florence, Italy.
| | - Giuseppe Roberto
- Agenzia regionale di sanità della Toscana, Osservatorio di epidemiologia, Florence, Italy.
| | | | - Elisa Martín-Merino
- BIFAP Database, Spanish Agency of Medicines and Medical Devices, Madrid, Spain.
| | - Talita Duarte-Salles
- Institut Universitari d'Investigació en Atenció Primària Jordi Gol (IDIAP Jordi Gol), Barcelona, Spain.
| | - Gino Picelli
- Epidemiological Information for Clinical Research from an Italian Network of Family Paediatricians (PEDIANET), Padova, Italy.
| | - Lara Tramontan
- Epidemiological Information for Clinical Research from an Italian Network of Family Paediatricians (PEDIANET), Padova, Italy; Consorzio Arsenal.IT, Veneto Region, Italy.
| | - Giorgia Danieli
- Epidemiological Information for Clinical Research from an Italian Network of Family Paediatricians (PEDIANET), Padova, Italy; Consorzio Arsenal.IT, Veneto Region, Italy
| | - Ana Correa
- University of Surrey, Guildford, Surrey GU2 7XH, UK.
| | - Chris McGee
- University of Surrey, Guildford, Surrey GU2 7XH, UK; Royal College of General Practitioners, Research and Surveillance Centre, 30 Euston Square, London NW1 2FB, UK.
| | - Benedikt F H Becker
- Erasmus University Medical Center, Post Box 2040, 3000 CA Rotterdam, Netherlands.
| | | | | | - Jorgen Bauwens
- University Children's Hospital, Basel, Switzerland; University of Basel, Switzerland; Brighton Collaboration Foundation, Switzerland.
| | | | - Gianfranco Spiteri
- European Centre for Disease Prevention and Control, Gustav III's Boulevard 40, 16973 Solna, Sweden.
| | - Emmanouela Sdona
- European Centre for Disease Prevention and Control, Gustav III's Boulevard 40, 16973 Solna, Sweden
| | - Daniel Weibel
- Erasmus University Medical Center, Post Box 2040, 3000 CA Rotterdam, Netherlands.
| | - Miriam Sturkenboom
- Julius Global Health, University Medical Center, Utrecht, Heidelberglaan 100, the Netherlands; P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan 1, 3001 Heverlee, Belgium; VACCINE.GRID Foundation, Spitalstrasse 33, Basel, Switzerland.
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Emborg HD, Kahlert J, Braeye T, Bauwens J, Bollaerts K, Danieli G, Duarte-Salles T, Glismann S, Huerta-Alvarez C, de Lusignan S, Martín-Merino E, McGee C, Correa A, Tramontan L, Weibel D, Sturkenboom M. ADVANCE system testing: Can coverage of pertussis vaccination be estimated in European countries using electronic healthcare databases: An example. Vaccine 2019; 38 Suppl 2:B22-B30. [PMID: 31677953 DOI: 10.1016/j.vaccine.2019.07.039] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 07/04/2019] [Accepted: 07/09/2019] [Indexed: 11/16/2022]
Abstract
INTRODUCTION The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public-private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines, using existing healthcare databases in Europe. The objective of this paper was to assess the feasibility of using electronic healthcare databases to estimate dose-specific acellular pertussis (aP) and whole cell pertussis (wP) vaccine coverage. METHODS Seven electronic healthcare databases in four European countries (Denmark (n = 2), UK (n = 2), Spain (n = 2) and Italy (n = 1)) participated in this study. Children were included from birth and followed up to age six years. Vaccination exposure was obtained from the databases and classified by type (aP or wP), and dose 1, 2 or 3. Coverage was estimated using period prevalence. For the 2006 birth cohort, two estimation methods for pertussis vaccine coverage, period prevalence and cumulative incidence were compared for each database. RESULTS The majority of the 2,575,576 children included had been vaccinated at the country-specific recommended ages. Overall, the estimated dose 3 coverage was 88-97% in Denmark (birth cohorts from 2003 to 2014), 96-100% in the UK (2003-2014), 95-98% in Spain (2004-2014) and 94% in Italy (2006-2007). The estimated dose 3 coverage per birth cohort in Denmark and the UK differed by 1-6% compared with national estimates, with our estimates mostly higher. The estimated dose 3 coverage in Spain differed by 0-2% with no consistent over- or underestimation. In Italy, the estimates were 3% lower compared with the national estimates. Except for Italy, for which the two coverage estimation methods generated the same results, the estimated cumulative incidence coverages were consistently 1-10% lower than period prevalence estimates. CONCLUSION This study showed that it was possible to provide consistent estimates of pertussis immunisation coverage from the electronic healthcare databases included, and that the estimates were comparable with the national estimates.
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Affiliation(s)
| | - Johnny Kahlert
- Aarhus University Hospital, Olof Palmes Alle 43-45, DK-8200 Aarhus, Denmark.
| | - Toon Braeye
- Sciensano, Rue Juliette Wytsmanstraat 14, 1050 Brussels, Belgium.
| | - Jorgen Bauwens
- University Children's Hospital Basel, PO Box, CH 4033 Basel, Switzerland; University of Basel, Switzerland; Brighton Collaboration Foundation, Switzerland.
| | | | - Giorgia Danieli
- Consorzio Arsenàl.IT, Veneto Region, Italy; PEDIANET, Padova, Italy.
| | - Talita Duarte-Salles
- Fundació Intitut Universitari per a la recerca a I'Atenció Primària de Salut Jordi Gol I Gurina (IDIAPJGol), Barcelona, Spain.
| | | | | | - Simon de Lusignan
- University of Surrey, Guildford, Surrey GU2 7XH, UK; Royal College of General Practitioners Research and Surveillance Centre, 30 Euston Square, London NW1 2FB, UK.
| | - Elisa Martín-Merino
- BIFAP Database, Spanish Agency of Medicines and Medical Devices, Madrid, Spain.
| | - Chris McGee
- University of Surrey, Guildford, Surrey GU2 7XH, UK; Royal College of General Practitioners Research and Surveillance Centre, 30 Euston Square, London NW1 2FB, UK.
| | - Ana Correa
- University of Surrey, Guildford, Surrey GU2 7XH, UK.
| | - Lara Tramontan
- Consorzio Arsenàl.IT, Veneto Region, Italy; PEDIANET, Padova, Italy.
| | - Daniel Weibel
- Erasmus University Medical Center, PO Box 2014, 3000 CA Rotterdam, the Netherlands; VACCINE.GRID Foundation, Spitalstrasse 33, Basel, Switzerland.
| | - Miriam Sturkenboom
- P-95 Epidemiology and Pharmacovigilance, Leuven, Belgium; VACCINE.GRID Foundation, Spitalstrasse 33, Basel, Switzerland; Julius Global Health, Julius Center, University Medical Center Utrecht, Heidelberglaan 100, the Netherlands.
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Braeye T, Bauchau V, Sturkenboom M, Emborg HD, García AL, Huerta C, Merino EM, Bollaerts K. Estimation of vaccination coverage from electronic healthcare records; methods performance evaluation - A contribution of the ADVANCE-project. PLoS One 2019; 14:e0222296. [PMID: 31532806 PMCID: PMC6750592 DOI: 10.1371/journal.pone.0222296] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 08/26/2019] [Indexed: 11/19/2022] Open
Abstract
INTRODUCTION The Accelerated Development of VAccine beNefit-risk Collaboration in Europe (ADVANCE) is a public private collaboration aiming to develop and test a system for rapid benefit-risk (B/R) monitoring of vaccines, using existing electronic healthcare record (eHR) databases in Europe. Part of the data in such sources is missing due to incomplete follow-up hampering the accurate estimation of vaccination coverage. We compared different methods for coverage estimation from eHR databases; naïve period prevalence, complete case period prevalence, period prevalence adjusted for follow-up time, Kaplan-Meier (KM) analysis and (adjusted) inverse probability weighing (IPW). METHODS We created simulation scenarios with different proportions of completeness of follow-up. Both completeness independent and dependent from vaccination date and status were considered. The root mean squared error (RMSE) and relative difference between the estimated and true coverage were used to assess the performance of the different methods for each of the scenarios. We included data examples on the vaccination coverage of human papilloma virus and pertussis component containing vaccines from the Spanish BIFAP database. RESULTS Under completeness independent from vaccination date or status, several methods provided estimates with bias close to zero. However, when dependence between completeness of follow-up and vaccination date or status was present, all methods generated biased estimates. The IPW/CDF methods were generally the least biased. Preference for a specific method should be based on the type of censoring and type of dependence between completeness of follow-up and vaccination. Additional insights into these aspects, might be gained by applying several methods.
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Affiliation(s)
- Toon Braeye
- Sciensano, Brussels, Belgium
- Hasselt University, Hasselt, Belgium
- * E-mail:
| | | | - Miriam Sturkenboom
- P95 Epidemiology and Pharmacovigilance, Leuven, Belgium
- VACCINE.GRID foundation, Basel, Switzerland
- University Medical Center Utrecht, Julius Global Health, Utrecht, the Netherlands
| | | | - Ana Llorente García
- BIFAP database, Spanish Agency of Medicines and Medical Devices, Madrid, Spain
| | - Consuelo Huerta
- BIFAP database, Spanish Agency of Medicines and Medical Devices, Madrid, Spain
| | - Elisa Martin Merino
- BIFAP database, Spanish Agency of Medicines and Medical Devices, Madrid, Spain
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Bollaerts K, Alexandridou M, Verstraeten T. Risk factors for modified vaccine effectiveness of the live attenuated zoster vaccine among the elderly in England. Vaccine X 2019; 1:100007. [PMID: 31384729 PMCID: PMC6668231 DOI: 10.1016/j.jvacx.2019.100007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 12/11/2018] [Accepted: 12/14/2018] [Indexed: 12/30/2022] Open
Abstract
Background The United Kingdom introduced routine vaccination with the live-attenuated zoster vaccine for 70 year-olds in 2013, with the vaccine also offered to 79 year-olds as part of a catch-up campaign. In the subsequent years, the catch-up campaign was extended to also include adults aged 78 years. We investigated 14 pre-identified potential risk factors for potential modified vaccine effectiveness. Methods This retrospective cohort study in England included subjects born in 1943-1946 (the routine cohort) and in 1934-1937 (the catch-up cohort). We used the Clinical Practice Research Datalink (CPRD) to identify herpes zoster (HZ) cases and the risk factors: age, gender, ethnicity, socio-economic status, asthma, type 2 diabetes, chronic obstructive pulmonary disease, smoking, body mass index, immunosuppression, history of HZ, co-administration with influenza or pneumococcal vaccine. We derived HZ incidence by risk groups, overall vaccine effectiveness (VE) and modified VE expressed as relative differences in VE from Poisson regression models. Results Overall VE was 66.8% [95% CI: 62.2; 71.0]. Two out of the 14 investigated risk factors modified the HZ VE. Notably, lower VE was observed in diabetics and in persons with a history of HZ with relative differences in VE of -22·2%, [95% CI: -39·6, -4·5] and -22·5%, [95% CI: -44·9, -0·1]. Conclusions Live-attenuated zoster vaccine protection against HZ was lower in type 2 diabetics and in subjects with a history of HZ. Contrary to clinical trial results, age did not affect the observed VE. Further study is required to gain insights into why certain risk groups are less protected. Identifying and understanding the effect modifiers of VE is important for future vaccine development as well as vaccine recommendations.
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Affiliation(s)
- Kaatje Bollaerts
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III Laan 1, 3001 Leuven, Belgium
| | - Maria Alexandridou
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III Laan 1, 3001 Leuven, Belgium
| | - Thomas Verstraeten
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III Laan 1, 3001 Leuven, Belgium
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Bollaerts K, Verstraeten T, Cohet C. Observational studies of non-specific effects of Diphtheria-Tetanus-Pertussis vaccines in low-income countries: Assessing the potential impact of study characteristics, bias and confounding through meta-regression. Vaccine 2018; 37:34-40. [PMID: 30471957 DOI: 10.1016/j.vaccine.2018.11.049] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 11/14/2018] [Accepted: 11/16/2018] [Indexed: 11/30/2022]
Abstract
INTRODUCTION It has been suggested that some vaccines have effects beyond protection against the diseases they target, called non-specific effects (NSEs). In 2016, a systematic review by Higgins et al., commissioned by the WHO Strategic Advisory Group of Experts (SAGE) on immunization, estimated the relative risk (RR) of all-cause mortality after whole-cell Diphtheria-Tetanus-Pertussis (DTwP) vaccination to be 1.38 (95% CI: 0.92-2.08), and described these potential NSEs as inconsistent. However, the selection of studies for meta-analysis, based on their proneness to bias and confounding, was debated. OBJECTIVE To identify study characteristics and postulated risks of bias and confounding that might have impacted the RR of all-cause mortality after DTwP vaccination in observational studies conducted in low-income countries. METHODS Based on methodological considerations on study design and analysis, we systematically assessed all 17 DTwP studies from the Higgins et al. review for risk of selection bias, exposure and outcome misclassification, confounding and differential co-interventions. We used meta-regression to assess the impact of study characteristics and the postulated risks of bias and confounding on the RR estimates, and looked for outlying and influential risk estimates. Permutation tests were performed to control for false-positive findings. RESULTS The overall RR of all-cause mortality after DTwP vaccination including all but one outlying and influential study was 1.32 (95% CI: 0.83-2.08). Based on uni-variable meta-regression, we found that study location (p = 0.01), studies using the landmark approach (p = 0.015) and studies at high risk of exposure misclassification (p = 0.036) were significantly associated with increased RR estimates whereas studies at high risk of selection bias (p = 0.059) showed borderline significance. The results further suggest these effect modifiers are clustered in studies conducted in West-Africa. CONCLUSION The increased RR of all-cause mortality after DTwP might be confined to West-African countries and/or certain postulated risks of bias might have inflated these RRs.
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Pirçon JY, Talarico CA, Bollaerts K, Hausdorff WP, Clarke CJ. The choice of analytical methodology can alter conclusions regarding herd effects of paediatric pneumococcal vaccination programmes. Vaccine 2018; 36:6933-6943. [DOI: 10.1016/j.vaccine.2018.10.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/25/2018] [Accepted: 10/02/2018] [Indexed: 10/28/2022]
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Bollaerts K, De Smedt T, Donegan K, Titievsky L, Bauchau V. Benefit-Risk Monitoring of Vaccines Using an Interactive Dashboard: A Methodological Proposal from the ADVANCE Project. Drug Saf 2018; 41:775-786. [PMID: 29582392 PMCID: PMC6061437 DOI: 10.1007/s40264-018-0658-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
INTRODUCTION New vaccines are launched based on their benefit-risk (B/R) profile anticipated from clinical development. Proactive post-marketing surveillance is necessary to assess whether the vaccination uptake and the B/R profile are as expected and, ultimately, whether further public health or regulatory actions are needed. There are several, typically not integrated, facets of post-marketing vaccine surveillance: the surveillance of vaccination coverage, vaccine safety, effectiveness and impact. OBJECTIVE With this work, we aim to assess the feasibility and added value of using an interactive dashboard as a potential methodology for near real-time monitoring of vaccine coverage and pre-specified health benefits and risks of vaccines. METHODS We developed a web application with an interactive dashboard for B/R monitoring. The dashboard is demonstrated using simulated electronic healthcare record data mimicking the introduction of rotavirus vaccination in the UK. The interactive dashboard allows end users to select certain parameters, including expected vaccine effectiveness, age groups, and time periods and allows calculation of the incremental net health benefit (INHB) as well as the incremental benefit-risk ratio (IBRR) for different sets of preference weights. We assessed the potential added value of the dashboard by user testing amongst a range of stakeholders experienced in the post-marketing monitoring of vaccines. RESULTS The dashboard was successfully implemented and demonstrated. The feedback from the potential end users was generally positive, although reluctance to using composite B/R measures was expressed. CONCLUSION The use of interactive dashboards for B/R monitoring is promising and received support from various stakeholders. In future research, the use of such an interactive dashboard will be further tested with real-life data as opposed to simulated data.
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Affiliation(s)
- Kaatje Bollaerts
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III laan 1, 3001, Leuven, Belgium.
| | - Tom De Smedt
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III laan 1, 3001, Leuven, Belgium
| | - Katherine Donegan
- Medicines and Healthcare products Regulatory Agency, Buckingham Palace Road 151, London, SW1W 9SZ, United Kingdom
| | - Lina Titievsky
- Worldwide Research and Development, Pfizer Inc, East 42nd St 235, New York City, NY 10017, NY, USA
| | - Vincent Bauchau
- GlaxoSmithKline Vaccines, Avenue Fleming 20, 1300, Wavre, Belgium
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De Smedt T, Merrall E, Macina D, Perez-Vilar S, Andrews N, Bollaerts K. Bias due to differential and non-differential disease- and exposure misclassification in studies of vaccine effectiveness. PLoS One 2018; 13:e0199180. [PMID: 29906276 PMCID: PMC6003693 DOI: 10.1371/journal.pone.0199180] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 06/01/2018] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Studies of vaccine effectiveness (VE) rely on accurate identification of vaccination and cases of vaccine-preventable disease. In practice, diagnostic tests, clinical case definitions and vaccination records often present inaccuracies, leading to biased VE estimates. Previous studies investigated the impact of non-differential disease misclassification on VE estimation. METHODS We explored, through simulation, the impact of non-differential and differential disease- and exposure misclassification when estimating VE using cohort, case-control, test-negative case-control and case-cohort designs. The impact of misclassification on the estimated VE is demonstrated for VE studies on childhood seasonal influenza and pertussis vaccination. We additionally developed a web-application graphically presenting bias for user-selected parameters. RESULTS Depending on the scenario, the misclassification parameters had differing impacts. Decreased exposure specificity had greatest impact for influenza VE estimation when vaccination coverage was low. Decreased exposure sensitivity had greatest impact for pertussis VE estimation for which high vaccination coverage is typically achieved. The impact of the exposure misclassification parameters was found to be more noticeable than that of the disease misclassification parameters. When misclassification is limited, all study designs perform equally. In case of substantial (differential) disease misclassification, the test-negative design performs worse. CONCLUSIONS Misclassification can lead to significant bias in VE estimates and its impact strongly depends on the scenario. We developed a web-application for assessing the potential (joint) impact of possibly differential disease- and exposure misclassification that can be modified by users to their own study scenario. Our results and the simulation tool may be used to guide better design, conduct and interpretation of future VE studies.
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Affiliation(s)
- Tom De Smedt
- P95 Epidemiology and Pharmacovigilance, Leuven, Belgium
| | | | | | - Silvia Perez-Vilar
- FISABIO-Public Health, Valencia, Spain
- Erasmus University Medical Center, Rotterdam, The Netherlands
| | - Nick Andrews
- Statistics, Modelling, and Economics Department, Public Health England, Colindale, London, United Kingdom
| | - Kaatje Bollaerts
- P95 Epidemiology and Pharmacovigilance, Leuven, Belgium
- * E-mail:
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Baay M, Bollaerts K, Verstraeten T. A systematic review and meta-analysis on the safety of newly adjuvanted vaccines among older adults. Vaccine 2018; 36:4207-4214. [PMID: 29885773 DOI: 10.1016/j.vaccine.2018.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 05/31/2018] [Accepted: 06/01/2018] [Indexed: 10/14/2022]
Abstract
INTRODUCTION New adjuvants have been developed to improve the efficacy of vaccines and for dose-sparing capacity and may overcome immuno senescence in the elderly. We reviewed the safety of newly-adjuvanted vaccines in older adults. METHODS We searched Medline for clinical trials (CTs) including new adjuvant systems (AS01, AS02, AS03, or MF59), used in older adults, published between 01/1995 and 09/2017. Safety outcomes were: serious adverse events (SAEs); solicited local and general AEs (reactogenicity); unsolicited AEs; and potentially immune-mediated diseases (pIMDs). Standard random effects meta-analyses were conducted by type of safety event and adjuvant type, reporting Relative Risks (RR) with 95% confidence intervals (95% CI). RESULTS We identified 1040 publications, from which we selected 7, 7, and 12 CTs on AS01/AS02, AS03 and MF59, respectively. 47,602 study participants received newly-adjuvanted vaccine and 44,521 control vaccine, or placebo. Rates of SAEs (RR = 0.99, 95% CI = 0.96-1.02), deaths (RR = 0.99, 95% CI = 0.92-1.06) and pIMDs (RR = 0.94, 95% CI = 0.79-1.1) were comparable in newly-adjuvanted and control groups. Vaccine-related SAEs occurred in <1% of the subjects in both groups. The reactogenicity of AS01/AS02 and AS03 adjuvanted vaccines was higher compared to control vaccines, whereas MF59-adjuvanted vaccines resulted only in more pain. Grade 3 reactogenicity was reported infrequently, with fatigue (RR = 2.48, 95% CI = 1.69-3.64), headache (RR = 2.94, 95% CI = 1.24-6.95), and myalgia (RR = 2.68, 95% CI = 1.86-3.80) occurring more frequently in newly-adjuvanted groups. Unsolicited AEs occurred slightly more frequently in newly-adjuvanted groups (RR = 1.04, 95% CI = 1.00-1.08). CONCLUSIONS Our review suggests that, within the clinical trial setting, the use of new adjuvants in older adults has not led to any safety concerns, with no increase in SAEs or fatalities. Higher rates for solicited AEs were observed, especially for AS01/AS02 and AS03 adjuvanted vaccines, but AEs were mostly mild and transient. Further evidence will need to come from the use of new adjuvants in the real-world setting, where larger numbers can be studied to potentially detect rare reactions.
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Affiliation(s)
- Marc Baay
- P95, Epidemiology and Pharmacovigilance Consulting and Services, Leuven, Belgium
| | - Kaatje Bollaerts
- P95, Epidemiology and Pharmacovigilance Consulting and Services, Leuven, Belgium
| | - Thomas Verstraeten
- P95, Epidemiology and Pharmacovigilance Consulting and Services, Leuven, Belgium.
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Petry KU, Bollaerts K, Bonanni P, Stanley M, Drury R, Joura E, Kjaer SK, Meijer CJLM, Riethmuller D, Soubeyrand B, Van Damme P, Bosch X. Estimation of the individual residual risk of cervical cancer after vaccination with the nonavalent HPV vaccine. Hum Vaccin Immunother 2018; 14:1800-1806. [PMID: 29553886 PMCID: PMC6067852 DOI: 10.1080/21645515.2018.1450125] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
BACKGROUND The nonavalent HPV (9vHPV) vaccine is indicated for active immunisation of individuals from the age of 9 years against cervical, vulvar, vaginal and anal premalignant lesions and cancers causally related to vaccine HPV high risk types 16, 18, 31, 33, 45, 52 and 58, and to the HPV low risk types 6 and 11, causing genital warts. OBJECTIVE To estimate the lifetime risk (up to the age of 75 years) for developing cervical cancer after vaccinating a HPV naïve girl (e.g. 9 to 12 years old) with the 9vHPV vaccine in the hypothetical absence of cervical cancer screening. METHODS We built Monte Carlo simulation models using historical pre-screening age-specific cancer incidence data and current mortality data from Denmark, Finland, Norway, Sweden and the UK. Estimates of genotype contribution fractions and vaccine efficacy were used to estimate the residual lifetime risk after vaccination assuming lifelong protection. RESULTS We estimated that, in the hypothetical absence of cervical screening and assuming lifelong protection, 9vHPV vaccination reduced the lifetime cervical cancer and mortality risks 7-fold with a residual lifetime cancer risks ranging from 1/572 (UK) to 1/238 (Denmark) and mortality risks ranging from 1/1488 (UK) to 1/851 (Denmark). After decades of repetitive cervical screenings, the lifetime cervical cancer and mortality risks was reduced between 2- and 4-fold depending on the country. CONCLUSION Our simulations demonstrate how evidence can be generated to support decision-making by individual healthcare seekers regarding cervical cancer prevention.
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Affiliation(s)
- Karl-Ulrich Petry
- a Department of Gynaecology and Obstetrics , Klinikum Wolfsburg , Germany
| | | | - Paolo Bonanni
- c Department of Health Sciences , University of Florence , Italy
| | - Margaret Stanley
- d Department of Pathology , Cambridge University , United Kingdom
| | | | - Elmar Joura
- f Department of Obstetrics and Gynaecology , Comprehensive Cancer Centre Vienna, Medical University of Vienna , Austria
| | - Susanne K Kjaer
- g Department of Gynaecology, Rigshospitalet , Copenhagen University Hospital and the Danish Cancer Society Research Centre , Copenhagen , Denmark
| | - Chris J L M Meijer
- h Department of Pathology , Free University Medical Centre , Netherlands
| | | | | | - Pierre Van Damme
- j Centre for Evaluation of Vaccination, Vaccine and Infectious Diseases Institute, University of Antwerp , Belgium
| | - Xavier Bosch
- k Cancer Research Epidemiology Program, Catalan Institute of Oncology, IDIBELL , Spain
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22
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McDonald SA, Nijsten D, Bollaerts K, Bauwens J, Praet N, van der Sande M, Bauchau V, de Smedt T, Sturkenboom M, Hahné S. Methodology for computing the burden of disease of adverse events following immunization. Pharmacoepidemiol Drug Saf 2018; 27:724-730. [PMID: 29575242 PMCID: PMC6055877 DOI: 10.1002/pds.4419] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 01/23/2018] [Accepted: 02/02/2018] [Indexed: 11/18/2022]
Abstract
Purpose Composite disease burden measures such as disability‐adjusted life‐years (DALY) have been widely used to quantify the population‐level health impact of disease or injury, but application has been limited for the estimation of the burden of adverse events following immunization. Our objective was to assess the feasibility of adapting the DALY approach for estimating adverse event burden. Methods We developed a practical methodological framework, explicitly describing all steps involved: acquisition of relative or absolute risks and background event incidence rates, selection of disability weights and durations, and computation of the years lived with disability (YLD) measure, with appropriate estimation of uncertainty. We present a worked example, in which YLD is computed for 3 recognized adverse reactions following 3 childhood vaccination types, based on background incidence rates and relative/absolute risks retrieved from the literature. Results YLD provided extra insight into the health impact of an adverse event over presentation of incidence rates only, as severity and duration are additionally incorporated. As well as providing guidance for the deployment of DALY methodology in the context of adverse events associated with vaccination, we also identified where data limitations potentially occur. Conclusions Burden of disease methodology can be applied to estimate the health burden of adverse events following vaccination in a systematic way. As with all burden of disease studies, interpretation of the estimates must consider the quality and accuracy of the data sources contributing to the DALY computation.
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Affiliation(s)
- Scott A. McDonald
- National Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | - Danielle Nijsten
- National Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
| | | | - Jorgen Bauwens
- University of Basel Children's HospitalBaselSwitzerland
- Brighton Collaboration FoundationBaselSwitzerland
| | | | - Marianne van der Sande
- National Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
- Department Public HealthInstitute of Tropical MedicineAntwerpBelgium
| | | | - Tom de Smedt
- P95 Pharmacovigilance and Epidemiology ServicesLeuvenBelgium
| | - Miriam Sturkenboom
- P95 Pharmacovigilance and Epidemiology ServicesLeuvenBelgium
- VACCINE.GRID FoundationBaselSwitzerland
| | - Susan Hahné
- National Institute for Public Health and the Environment (RIVM)BilthovenThe Netherlands
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Tin Tin Htar M, Stuurman AL, Ferreira G, Alicino C, Bollaerts K, Paganino C, Reinert RR, Schmitt HJ, Trucchi C, Vestraeten T, Ansaldi F. Effectiveness of pneumococcal vaccines in preventing pneumonia in adults, a systematic review and meta-analyses of observational studies. PLoS One 2017; 12:e0177985. [PMID: 28542347 PMCID: PMC5441633 DOI: 10.1371/journal.pone.0177985] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2016] [Accepted: 05/05/2017] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION S. pneumoniae can cause a wide spectrum of diseases, including invasive pneumococcal disease and pneumonia. Two types of pneumococcal vaccines are indicated for use in adults: 23-valent pneumococcal polysaccharide vaccines (PPV23) and a 13-valent pneumococcal conjugate vaccine (PCV13). OBJECTIVE To systematically review the literature assessing pneumococcal vaccine effectiveness (VE) against community-acquired pneumonia (CAP) in adults among the general population, the immunocompromised and subjects with underlying risk factors in real-world settings. METHODS We searched for peer-reviewed observational studies published between 1980 and 2015 in Pubmed, SciELO or LILACS, with pneumococcal VE estimates against CAP, pneumococcal CAP or nonbacteremic pneumococcal CAP. Meta-analyses and meta-regression for VE against CAP requiring hospitalization in the general population was performed. RESULTS 1159 unique articles were retrieved of which 33 were included. No studies evaluating PCV13 effectiveness were found. Wide ranges in PPV23 effectiveness estimates for any-CAP were observed among adults ≥65 years (-143% to 60%). The meta-analyzed VE estimate for any-CAP requiring hospitalization in the general population was 10.2% (95%CI: -12.6; 33.0). The meta-regression indicates that VE against any-CAP requiring hospitalization is significantly lower in studies with a maximum time since vaccination ≥60 months vs. <60 months and in countries with the pediatric PCV vaccine available on the private market. However, these results should be interpreted cautiously due to the high influence of two studies. The VE estimates for pneumococcal CAP hospitalization ranged from 32% (95%CI: -18; 61) to 51% (95%CI: 16; 71) in the general population. CONCLUSIONS Wide ranges in PPV23 effectiveness estimates for any-CAP were observed, likely due to a great diversity of study populations, circulation of S. pneumoniae serotypes, coverage of pediatric pneumococcal vaccination, case definition and time since vaccination. Despite some evidence for short-term protection, effectiveness of PPV23 against CAP was not consistent in the general population, the immunocompromised and subjects with underlying risk factors.
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Affiliation(s)
| | - Anke L. Stuurman
- P95 Epidemiology and Pharmacovigilance Consulting and Services, P95, Leuven, Belgium
| | - Germano Ferreira
- P95 Epidemiology and Pharmacovigilance Consulting and Services, P95, Leuven, Belgium
| | - Cristiano Alicino
- Department of Health Sciences (DiSSal), University of Genoa, Genoa, Italy
| | - Kaatje Bollaerts
- P95 Epidemiology and Pharmacovigilance Consulting and Services, P95, Leuven, Belgium
| | - Chiara Paganino
- Department of Health Sciences (DiSSal), University of Genoa, Genoa, Italy
| | - Ralf René Reinert
- Pfizer: Vaccines Medical Development and Scientific Clinical Affairs, Pfizer Inc, Paris, France
| | - Heinz-Josef Schmitt
- Pfizer: Vaccines Medical Development and Scientific Clinical Affairs, Pfizer Inc, Paris, France
| | - Cecilia Trucchi
- Department of Health Sciences (DiSSal), University of Genoa, Genoa, Italy
| | - Thomas Vestraeten
- P95 Epidemiology and Pharmacovigilance Consulting and Services, P95, Leuven, Belgium
| | - Filippo Ansaldi
- Department of Health Sciences (DiSSal), University of Genoa, Genoa, Italy
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Riera-Montes M, Bollaerts K, Heininger U, Hens N, Gabutti G, Gil A, Nozad B, Mirinaviciute G, Flem E, Souverain A, Verstraeten T, Hartwig S. Estimation of the burden of varicella in Europe before the introduction of universal childhood immunization. BMC Infect Dis 2017; 17:353. [PMID: 28521810 PMCID: PMC5437534 DOI: 10.1186/s12879-017-2445-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 05/07/2017] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Varicella is generally considered a mild disease. Disease burden is not well known and country-level estimation is challenging. As varicella disease is not notifiable, notification criteria and rates vary between countries. In general, existing surveillance systems do not capture cases that do not seek medical care, and most are affected by underreporting and underascertainment. We aimed to estimate the overall varicella disease burden in Europe to provide critical information to support decision-making regarding varicella vaccination. METHODS We conducted a systematic literature review to identify all available epidemiological data on varicella IgG antibody seroprevalence, primary care and hospitalisation incidence, and mortality. We then developed methods to estimate age-specific varicella incidence and annual number of cases by different levels of severity (cases in the community, health care seekers in primary care and hospitals, and deaths) for all countries belonging to the European Medicines Agency (EMA) region and Switzerland. RESULTS In the absence of universal varicella immunization, the burden of varicella would be substantial with a total of 5.5 million (95% CI: 4.7-6.4) varicella cases occurring annually across Europe. Variation exists between countries but overall the majority of cases (3 million; 95% CI: 2.7-3.3) would occur in children <5 years. Annually, 3-3.9 million patients would consult a primary care physician, 18,200-23,500 patients would be hospitalised, and 80 varicella-related deaths would occur (95% CI: 19-822). CONCLUSIONS Varicella disease burden is substantial. Most cases occur in children <5 years old but adults require hospitalisation more often and are at higher risk of death. This information should be considered when planning and evaluating varicella control strategies. A better understanding of the driving factors of country-specific differences in varicella transmission and health care utilization is needed. Improving and standardizing varicella surveillance in Europe, as initiated by the European Centre for Disease Prevention and Control (ECDC), is important to improve data quality to facilitate inter-country comparison.
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Affiliation(s)
- Margarita Riera-Montes
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III Laan 1, 3001, Leuven, Belgium.
| | - Kaatje Bollaerts
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III Laan 1, 3001, Leuven, Belgium
| | - Ulrich Heininger
- Division of Paediatric Infectious Diseases and Vaccinology, University of Basel Children's Hospital, CH-4056, Basel, Switzerland
| | - Niel Hens
- Interuniversity Institute for Biostatistics and statistical Bioinformatics, Hasselt University, Antwerp, Belgium.,Centre for Health Economics Research and Modelling Infectious Diseases and Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - Giovanni Gabutti
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Angel Gil
- Universidad Rey Juan Carlos, Madrid, Spain
| | - Bayad Nozad
- Department of Primary Care and Public Health, Imperial College London, London, UK
| | - Grazina Mirinaviciute
- Department of Infectious Disease Epidemiology and Modelling, Norwegian Institute of Public Health, Oslo, Norway
| | - Elmira Flem
- Department of Infectious Disease Epidemiology and Modelling, Norwegian Institute of Public Health, Oslo, Norway
| | | | - Thomas Verstraeten
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III Laan 1, 3001, Leuven, Belgium
| | - Susanne Hartwig
- Sanofi Pasteur MSD, 162 avenue Jean Jaurès, 69007, Lyon, France
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Baay M, Bollaerts K, Struchiner C, Verstraeten T. Background rates of disease in Latin American children from a rotavirus vaccine study. Hum Vaccin Immunother 2017; 13:1916-1920. [PMID: 28441094 DOI: 10.1080/21645515.2017.1320007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
BACKGROUND Knowledge of background rates of adverse events is crucial to assess vaccine safety concerns. We used data from a rotavirus vaccine study (Ruiz-Palacios et al., NEJM, 2006) including 63,225 infants from 11 Latin American countries to investigate reporting rates of serious adverse events (SAEs) among these infants, and describe rates by country, gender, age, and season. METHODS For this randomized, double-blind, placebo-controlled, phase 3 trial, investigators from Argentina, Brazil, Chile, Colombia, Dominican Republic, Honduras, Mexico, Nicaragua, Panama, Peru, and Venezuela recruited 6-to-13-week-old healthy infants. The infants received 2 oral doses of vaccine or placebo. The study population was followed 100 d for the assessment of adverse events. SAEs were captured by an active surveillance system. RESULTS Strong differences in event rates could be observed between countries (min. 48.1/10,000 person-years in Dominican Republic/Peru; max. 296.2/10,000 person-years in Brazil) and between genders: gastroenteritis, pneumonia, bronchiolitis and bronchitis occurred significantly more frequently in males. In addition, infections and infestations, and most disorders, including immune system and cardiac disorders, were more frequent at earlier ages. Finally, looking at seasonality we noted higher rates of SAEs in the second half of the year in all countries except Mexico. DISCUSSION Significant differences in reporting rates of SAEs between countries, gender and calendar months illustrate the importance of knowing the local epidemiology when interpreting SAEs. Data from clinical trials can be used to better understand background rates of diseases that may be perceived as potential adverse events following immunization.
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Affiliation(s)
- Marc Baay
- a P95, Epidemiology and Pharmacovigilance Consulting and Services , Leuven , Belgium
| | - Kaatje Bollaerts
- a P95, Epidemiology and Pharmacovigilance Consulting and Services , Leuven , Belgium
| | - Claudio Struchiner
- b Programa de Computação Científica, Fundação Oswaldo Cruz , Rio de Janeiro , RJ , Brazil
| | - Thomas Verstraeten
- a P95, Epidemiology and Pharmacovigilance Consulting and Services , Leuven , Belgium
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Abstract
Quantile regression is an alternative to OLS regression. In quantile regression, the sum of absolute deviations or the L1-norm is minimized, whereas the sum of squared deviations or the L2-norm is minimized in OLS regression. Quantile regression has the advantage over OLS-regression of being more robust to outlying observations. Furthermore, quantile regression provides information complementing the information provided by OLS-regression. In this study, a non-parametric approach to quantile regression is presented, which constrains the estimated-quantile function to be monotone increasing. In particular, P-splines with an additional asymmetric penalty enforcing monotonicity are used within an L1-framework. This can be translated into a linear programming problem, which will be solved using an interior point algorithm. As an illustration, the presented approach will be applied to estimate quantile growth curves and quantile antibody levels as a function of age.
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Affiliation(s)
| | | | - Marc Aerts
- Center for Statistics, University Hasselt, Belgium
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Bollaerts K, Shinde V, Dos Santos G, Ferreira G, Bauchau V, Cohet C, Verstraeten T. Application of Probabilistic Multiple-Bias Analyses to a Cohort- and a Case-Control Study on the Association between Pandemrix™ and Narcolepsy. PLoS One 2016; 11:e0149289. [PMID: 26901063 PMCID: PMC4762678 DOI: 10.1371/journal.pone.0149289] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Accepted: 12/24/2015] [Indexed: 12/26/2022] Open
Abstract
Background An increase in narcolepsy cases was observed in Finland and Sweden towards the end of the 2009 H1N1 influenza pandemic. Preliminary observational studies suggested a temporal link with the pandemic influenza vaccine Pandemrix™, leading to a number of additional studies across Europe. Given the public health urgency, these studies used readily available retrospective data from various sources. The potential for bias in such settings was generally acknowledged. Although generally advocated by key opinion leaders and international health authorities, no systematic quantitative assessment of the potential joint impact of biases was undertaken in any of these studies. Methods We applied bias-level multiple-bias analyses to two of the published narcolepsy studies: a pediatric cohort study from Finland and a case-control study from France. In particular, we developed Monte Carlo simulation models to evaluate a potential cascade of biases, including confounding by age, by indication and by natural H1N1 infection, selection bias, disease- and exposure misclassification. All bias parameters were evidence-based to the extent possible. Results Given the assumptions used for confounding, selection bias and misclassification, the Finnish rate ratio of 13.78 (95% CI: 5.72–28.11) reduced to a median value of 6.06 (2.5th- 97.5th percentile: 2.49–15.1) and the French odds ratio of 5.43 (95% CI: 2.6–10.08) to 1.85 (2.5th—97.5th percentile: 0.85–4.08). Conclusion We illustrate multiple-bias analyses using two studies on the Pandemrix™-narcolepsy association and advocate their use to better understand the robustness of study findings. Based on our multiple-bias models, the observed Pandemrix™-narcolepsy association consistently persists in the Finnish study. For the French study, the results of our multiple-bias models were inconclusive.
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Affiliation(s)
- Kaatje Bollaerts
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III Laan 1, 3001 Leuven, Belgium
- * E-mail:
| | - Vivek Shinde
- GSK Vaccines, 2301 Renaissance Boulevard, King of Prussia, PA 19406, United States of America
| | - Gaël Dos Santos
- Business & Decision Life Sciences (contractor for GSK Vaccines), Rue Saint Lambert 141, 1200 Brussels, Belgium
| | | | | | | | - Thomas Verstraeten
- P95 Pharmacovigilance and Epidemiology Services, Koning Leopold III Laan 1, 3001 Leuven, Belgium
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Stassijns J, Bollaerts K, Baay M, Verstraeten T. A systematic review and meta-analysis on the safety of newly adjuvanted vaccines among children. Vaccine 2015; 34:714-22. [PMID: 26740250 DOI: 10.1016/j.vaccine.2015.12.024] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2015] [Revised: 12/08/2015] [Accepted: 12/10/2015] [Indexed: 12/15/2022]
Abstract
INTRODUCTION New adjuvants such as the AS- or the MF59-adjuvants improve vaccine efficacy and facilitate dose-sparing. Their use in influenza and malaria vaccines has resulted in a large body of evidence on their clinical safety in children. METHODS We carried out a systematic search for safety data from published clinical trials on newly adjuvanted vaccines in children ≤10 years of age. Serious adverse events (SAEs), solicited AEs, unsolicited AEs and AEs of special interest were evaluated for four new adjuvants: the immuno-stimulants containing adjuvant systems AS01 and AS02, and the squalene containing oil-in-water emulsions AS03 and MF59. Relative risks (RR) were calculated, comparing children receiving newly adjuvanted vaccines to children receiving other vaccines with a variety of antigens, both adjuvanted and unadjuvanted. RESULTS Twenty-nine trials were included in the meta-analysis, encompassing 25,056 children who received at least one dose of the newly adjuvanted vaccines. SAEs did not occur more frequently in adjuvanted groups (RR 0.85, 95%CI 0.75-0.96). Our meta-analyses showed higher reactogenicity following administration of newly adjuvanted vaccines, however, no consistent pattern of solicited AEs was observed across adjuvant systems. Pain was the most prevalent AE, but often mild and of short duration. No increased risks were found for unsolicited AEs, febrile convulsions, potential immune mediated diseases and new onset of chronic diseases. CONCLUSIONS Our meta-analysis did not show any safety concerns in clinical trials of the newly adjuvanted vaccines in children ≤10 years of age. An unexplained increase of meningitis in one Phase III AS01-adjuvanted malaria trial and the link between narcolepsy and the AS03-adjuvanted pandemic vaccine illustrate that continued safety monitoring is warranted.
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Affiliation(s)
- Jorgen Stassijns
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium
| | - Kaatje Bollaerts
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium
| | - Marc Baay
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium
| | - Thomas Verstraeten
- P-95, Epidemiology and Pharmacovigilance Consulting and Services, Koning Leopold III Laan 1, 3001 Heverlee, Belgium.
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Verstraeten T, Cohet C, Dos Santos G, Ferreira GL, Bollaerts K, Bauchau V, Shinde V. Pandemrix™ and narcolepsy: A critical appraisal of the observational studies. Hum Vaccin Immunother 2015; 12:187-93. [PMID: 26379011 PMCID: PMC4962758 DOI: 10.1080/21645515.2015.1068486] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A link between Pandemrix™ (AS03-adjuvanted H1N1 pandemic influenza vaccine, GSK Vaccines, Belgium) and narcolepsy was first suspected in 2010 in Sweden and Finland following a number of reports in children and adolescents. Initial scepticism about the reported association faded as additional countries reported similar findings, leading several regulatory authorities to restrict the use of Pandemrix™. The authors acknowledge that currently available data suggest an increased risk of narcolepsy following vaccination with Pandemrix™; however, from an epidemiologist's perspective, significant methodological limitations of the studies have not been fully addressed and raise questions about the reported risk estimates. We review the most important biases and confounders that potentially occurred in 12 European studies of the observed association between Pandemrix™ and narcolepsy, and call for further analyses and debate.
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Affiliation(s)
| | | | - Gaël Dos Santos
- c Business & Decision Life Sciences (contractor for GSK Vaccines) ; Brussels , Belgium
| | - Germano Lc Ferreira
- a P95 Pharmacovigilance and Epidemiology Services ; Leuven , Belgium.,b GSK Vaccines ; Wavre , Belgium
| | - Kaatje Bollaerts
- a P95 Pharmacovigilance and Epidemiology Services ; Leuven , Belgium
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Bollaerts K, Fierens S, Van Bladel L, Simons K, Sonck M, Poffijn A, Geraets D, Gosselin P, Van Oyen H, Francart J, Van Nieuwenhuyse A. Thyroid cancer incidence in the vicinity of nuclear sites in Belgium, 2000-2008. Thyroid 2014; 24:906-17. [PMID: 24624964 DOI: 10.1089/thy.2013.0227] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
BACKGROUND Public health concern about nuclear activities have existed since the 1980s. Most studies on this subject investigated childhood leukemia. Thyroid cancer may be another health outcome of interest, because some nuclear installations are a potential source of radioactive iodine isotopes in the environment and because thyroid cancer is known to occur after exposure to these isotopes. METHODS This study describes an ecological study investigating whether there is excessive thyroid cancer incidence among residents living in the vicinity of nuclear sites. Single-site analyses using indirect standardization (standardized incidence ratios [SIRs]) and Poisson regression modeling (rate ratios [RRs]) were conducted. The proximity area is typically defined as a circular zone with a radius of 20 km centered on the site. However, the choice of the size of this area is somewhat arbitrary. Therefore, a sensitivity analysis was carried out to investigate whether the results vary with radii of increasing proximity. RESULTS No increased thyroid cancer incidence was found within the 20 km proximity area around the nuclear power plants of Doel (SIR=0.74 [95% confidence interval (CI)=0.64; 0.84] and RR=0.72 [95% CI=0.63; 0.83]) and Tihange (SIR=0.86 [95% CI=0.70; 1.01] and RR=0.85 [95% CI=0.70; 1.02]). For the sites of Mol-Dessel and Fleurus, where a combination of nuclear research and industrial activities are located, the incidences of thyroid cancer within the 20 km proximity area were higher than expected (Mol-Dessel: SIR=1.19 [95% CI=1.01; 1.36] and RR=1.19 [95% CI=1.02; 1.38]; Fleurus: SIR=1.15 [95% CI=1.02; 1.28] and RR=1.17 [95% CI=1.04; 1.33]). For Chooz, a French nuclear power plant close to the Belgian border, the results were unstable as a result of the small population denominator. For all Belgian nuclear sites, the results were generally insensitive to the choice of the proximity area. CONCLUSIONS No evidence for excessive thyroid cancer incidence around the Belgian nuclear power plants was found. On the other hand, an increased incidence of thyroid cancer was observed around the sites with other nuclear activities. Further research is recommended to verify whether the observed increases could be related to the site-specific nuclear activities.
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Affiliation(s)
- Kaatje Bollaerts
- 1 Scientific Institute of Public Health, Operational Direction Surveillance and Public Health , Brussels, Belgium
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Bollaerts K, Aerts M, Shkedy Z, Faes C, Van der Stede Y, Beutels P, Hens N. Estimating the population prevalence and force of infection directly from antibody titres. STAT MODEL 2012. [DOI: 10.1177/1471082x12457495] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The use of threshold values in order to diagnose individual subjects as being ‘susceptible’ or ‘infected or recovered/immune’ for a specific infection is virtually always prone to false positive, false negative or inconclusive classifications. Such misclassifications might lead to biased estimates for epidemiological parameters, such as the prevalence and the force of infection. In this article, we propose to estimate these epidemiological parameters directly from antibody titres, using an underlying mixture model. The method is applied to estimate the Salmonella serological prevalence in pigs and the age-dependent force of infection using serological data on the Varicella-Zoster virus (VZV) in humans. The threshold and direct method are compared through a simulation study.
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Affiliation(s)
- K Bollaerts
- Scientific Institute of Public Health, Brussels, Belgium
| | - M Aerts
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University & Katholieke Universiteit Leuven, Diepenbeek, Belgium
| | - Z Shkedy
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University & Katholieke Universiteit Leuven, Diepenbeek, Belgium
| | - C Faes
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University & Katholieke Universiteit Leuven, Diepenbeek, Belgium
| | - Y Van der Stede
- Veterinary and Agrochemical Research Centre, Brussels, Belgium
| | - P Beutels
- Centre for Health Economics Research and Modeling Infectious Diseases, Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
| | - N Hens
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University & Katholieke Universiteit Leuven, Diepenbeek, Belgium
- Centre for Health Economics Research and Modeling Infectious Diseases, Centre for the Evaluation of Vaccination, Vaccine & Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
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Persoons D, Bollaerts K, Smet A, Herman L, Heyndrickx M, Martel A, Butaye P, Catry B, Haesebrouck F, Dewulf J. The importance of sample size in the determination of a flock-level antimicrobial resistance profile for Escherichia coli in broilers. Microb Drug Resist 2011; 17:513-9. [PMID: 21875337 DOI: 10.1089/mdr.2011.0048] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Determining herd- or flock-specific antimicrobial resistance profiles is important to guide therapeutic use of antimicrobials and to assess risk factors for the development and spread of antimicrobial resistance. As such, it is of utmost importance to optimize the sampling strategy for the determination of herd-specific antimicrobial resistance profiles. However, the multitude of prevalences measured at the same time as well as the presence of variation both at the level of the animal and the bacterial population of concern make it impossible to use conventional sample size determination methods. In this article, the use of bootstrapping techniques for sample size determination was explored. In particular, one-stage and two-stage bootstrap samplings were used to determine the optimal number of animals and the optimal number of isolates within one animal. Results show that focus should be on the number of animals sampled rather than on the number of isolates tested within one animal.
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Affiliation(s)
- Davy Persoons
- Veterinary Epidemiology Unit, Department of Obstetrics, Reproduction, and Herd Health, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, Merelbeke, Belgium.
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Bollaerts K, Antoine J, Robesyn E, Van Proeyen L, Vomberg J, Feys E, De Decker E, Catry B. Timeliness of syndromic influenza surveillance through work and school absenteeism. Arch Public Health 2010. [PMCID: PMC3463027 DOI: 10.1186/0778-7367-68-3-115] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
In this paper, we investigate the usefulness of work and school absenteeism surveillance as an early warning system for influenza. In particular, time trends in daily absenteeism rates collected during the A(H1N1)2009 pandemic are compared with weekly incidence rates of influenza-like illness (ILI) obtained from the Belgian Sentinel General Practitioner (SGP) network. The results indicate a rise in absenteeism rates prior to the onset of the influenza epidemic, suggesting that absenteeism surveillance is a promising tool for early warning of influenza epidemics. To convincingly conclude on the usefulness of absenteeism data for early warning, additional data covering several influenza seasons is needed.
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Bollaerts K, Messens W, Aerts M, Dewulf J, Maes D, Grijspeerdt K, Van der Stede Y. Evaluation of scenarios for reducing human salmonellosis through household consumption of fresh minced pork meat. Risk Anal 2010; 30:853-865. [PMID: 20199654 DOI: 10.1111/j.1539-6924.2010.01368.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nontyphoidal salmonellosis is the second most frequently reported zoonotic disease in the European Union (EU) and is considered to be a major threat to human health worldwide. The most reported Salmonella serovar in the EU is S. Enteritidis, mainly associated with egg contamination, followed by S. Typhimurium, with the latter being the most predominant serovar isolated from pork. These findings suggest that reducing the Salmonella contamination in the pork production might be a good strategy to prevent and control human salmonellosis in the EU. Recently, a quantitative microbial risk assessment (QMRA) has been developed to assess the risks for human salmonellosis due to home consumption of fresh minced pork meat in Belgium. The newly developed risk model is called the METZOON model. In the current study, the METZOON model was used to evaluate the effectiveness of different hypothetical Salmonella mitigation strategies implemented at different stages of the minced pork production and consumption chain by means of a scenario analysis. To efficiently evaluate the mitigation strategies, model results were obtained by running simulations using the randomized complete block design. The effectiveness of a mitigation strategy is expressed using point and interval estimates of the effect size for dependent observations, expressed as the standardized difference in population means. The results indicate that the most effective strategies are taken during the slaughter processes of polishing, evisceration, and chilling, and during postprocessing, whereas interventions in the primary production and at the beginning of the slaughter process seem to have only a limited effect. Improving consumer awareness is found to be effective as well.
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Boone I, Van der Stede Y, Bollaerts K, Messens W, Vose D, Daube G, Aerts M, Mintiens K. Expert judgement in a risk assessment model for Salmonella spp. in pork: The performance of different weighting schemes. Prev Vet Med 2009; 92:224-34. [DOI: 10.1016/j.prevetmed.2009.08.020] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Boone I, Van der Stede Y, Bollaerts K, Vose D, Maes D, Dewulf J, Messens W, Daube G, Aerts M, Mintiens K. NUSAP method for evaluating the data quality in a quantitative microbial risk assessment model for Salmonella in the pork production chain. Risk Anal 2009; 29:502-517. [PMID: 19192236 DOI: 10.1111/j.1539-6924.2008.01181.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The numeral unit spread assessment pedigree (NUSAP) system was implemented to evaluate the quality of input parameters in a quantitative microbial risk assessment (QMRA) model for Salmonella spp. in minced pork meat. The input parameters were grouped according to four successive exposure pathways: (1) primary production (2) transport, holding, and slaughterhouse, (3) postprocessing, distribution, and storage, and (4) preparation and consumption. An inventory of 101 potential input parameters was used for building the QMRA model. The characteristics of each parameter were defined using a standardized procedure to assess (1) the source of information, (2) the sampling methodology and sample size, and (3) the distributional properties of the estimate. Each parameter was scored by a panel of experts using a pedigree matrix containing four criteria (proxy, empirical basis, method, and validation) to assess the quality, and this was graphically represented by means of kite diagrams. The parameters obtained significantly lower scores for the validation criterion as compared with the other criteria. Overall strengths of parameters related to the primary production module were significantly stronger compared to the other modules (the transport, holding, and slaughterhouse module, the processing, distribution, and storage module, and the preparation and consumption module). The pedigree assessment contributed to select 20 parameters, which were subsequently introduced in the QMRA model. The NUSAP methodology and kite diagrams are objective tools to discuss and visualize the quality of the parameters in a structured way. These two tools can be used in the selection procedure of input parameters for a QMRA, and can lead to a more transparent quality assurance in the QMRA.
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Affiliation(s)
- Ides Boone
- Veterinary and Agrochemical Research Centre (VAR), Coordination Centre for Veterinary Diagnostics, Groeselenberg 99, Brussels, Belgium
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Cortiñas Abrahantes J, Bollaerts K, Aerts M, Ogunsanya V, Van der Stede Y. Salmonella serosurveillance: different statistical methods to categorise pig herds based on serological data. Prev Vet Med 2009; 89:59-66. [PMID: 19272662 DOI: 10.1016/j.prevetmed.2009.01.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2007] [Revised: 01/22/2009] [Accepted: 01/27/2009] [Indexed: 11/24/2022]
Abstract
This study proposes three different statistical methods that can be applied in order to categorise pig herds into two groups (high seroreactors vs. low seroreactors) based on serological test results for Salmonella-specific antibodies in pigs. All proposed statistical methods were restricted to allocate about 10% of the herds into the group defined by each of the statistical approaches as high seroreactors. Previously, semi-parametric quantile regression has been used for this purpose, and here we compare it with two other alternatives: a naive method (based on the mean values) and another based on activity region finder methodology in combination with random forest regression models. The serological response values (the sample-to-positive ratio (S/P ratio)) of 13 649 pigs from 314 Belgian pig herds were used for this comparison. Nearly 14% of these herds were assigned to the high-seroreactor-herd group by at least one of these three methods. The corrected level of agreement was calculated together with the pair-wise agreement among all three methods in order to classify herds as high- or low-level seroreactors, resulting in an agreement level greater than 92%. The results obtained from a fourth method, which is adopted by the Belgian Federal Agency for the Safety of the Food Chain (FASFC), were also compared to the previous three methods. The methods were compared in terms of their agreement as well as their advantages and disadvantages. Recommendations for each applied method are presented in relation to the objectives and the requisite policy for classifying pig herds based on serological data.
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Affiliation(s)
- J Cortiñas Abrahantes
- Interuniversity Institute for Biostatistics and Statistical Bioinformatics, Hasselt University, Agoralaan 1, Diepenbeek B-3590, Belgium.
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Delhalle L, De Sadeleer L, Bollaerts K, Farnir F, Saegerman C, Korsak N, Dewulf J, De Zutter L, Daube G. Risk factors for Salmonella and hygiene indicators in the 10 largest Belgian pig slaughterhouses. J Food Prot 2008; 71:1320-9. [PMID: 18680928 DOI: 10.4315/0362-028x-71.7.1320] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A survey was conducted to collect data on Salmonella prevalence, Escherichia coli counts (ECCs), and aerobic bacteria colony counts (ACCs) on pig carcasses after chilling at the 10 largest Belgian pig slaughterhouses during 2000 through 2004. Potential risk factors of contamination associated with production parameters, technical descriptions of the installations, and cleaning and disinfection methods were assessed during investigations in the slaughterhouses. These variables were used first in a univariate analysis and then were extended to a multivariate analysis with a logistic mixed regression model for Salmonella and a linear mixed model for ECCs and ACCs with slaughterhouses as the random effect. The results indicated high variability concerning Salmonella contamination among the 10 slaughterhouses, with prevalence ranging from 2.6 to 34.3% according to the area of origin. The median ECC and median ACC ranged from -0.43 to 1.11 log CFU/cm2 and from 2.37 to 3.65 log CFU/cm2, respectively. The results of the logistic and linear regressions revealed that some working practices such as scalding with steam, second flaming after polishing, and complete cleaning and disinfection of the splitting machine several times a day were beneficial for reducing Salmonella prevalence, ECCs, and ACCs. Changing the carcass hooks just before chilling, using water as the cleaning method, and a higher frequency of disinfection of the lairage seemed to be protective against E. coli in the multivariate mixed linear model. The monitoring of critical points, slaughterhouse equipment, good slaughtering practices, and effective washing and disinfection are the keys to obtaining good microbiological results.
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Affiliation(s)
- L Delhalle
- Food Science Department, Microbiology Section, Faculty of Veterinary Medicine, University of Liège, Sart-Tilman, B43bis, 4000 Liège, Belgium.
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Abstract
The quantification of the relationship between the amount of microbial organisms ingested and a specific outcome such as infection, illness, or mortality is a key aspect of quantitative risk assessment. A main problem in determining such dose-response models is the availability of appropriate data. Human feeding trials have been criticized because only young healthy volunteers are selected to participate and low doses, as often occurring in real life, are typically not considered. Epidemiological outbreak data are considered to be more valuable, but are more subject to data uncertainty. In this article, we model the dose-illness relationship based on data of 20 Salmonella outbreaks, as discussed by the World Health Organization. In particular, we model the dose-illness relationship using generalized linear mixed models and fractional polynomials of dose. The fractional polynomial models are modified to satisfy the properties of different types of dose-illness models as proposed by Teunis et al. Within these models, differences in host susceptibility (susceptible versus normal population) are modeled as fixed effects whereas differences in serovar type and food matrix are modeled as random effects. In addition, two bootstrap procedures are presented. A first procedure accounts for stochastic variability whereas a second procedure accounts for both stochastic variability and data uncertainty. The analyses indicate that the susceptible population has a higher probability of illness at low dose levels when the combination pathogen-food matrix is extremely virulent and at high dose levels when the combination is less virulent. Furthermore, the analyses suggest that immunity exists in the normal population but not in the susceptible population.
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Abstract
Management of elderly patients with type II diabetes is complicated by age-related changes in physiology, comorbidities, polypharmacy and heterogeneity of functional status. A minimum goal in antidiabetic treatment in this population is to achieve a level of glycaemic control that avoids acute complications of diabetes, adverse effects and reduction in quality of life. Hypoglycaemia is a particular problem in elderly patients, and many antidiabetic agents pose increased risk for hypoglycaemia. In addition, many standard agents pose risks for older patients because of reduced renal function and common comorbidities. Newer agents based on enhancing incretin activity, including the glucagon-like peptide-1 mimetics exenatide and liraglutide and the oral dipeptidyl peptidase-4 inhibitors sitagliptin and vildagliptin, may offer particular advantages in elderly patients with diabetes.
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Affiliation(s)
- C Mathieu
- Katholieke Universiteit Leuven, Belgium, Leuven, Belgium.
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Abstract
In many research areas, especially within social and behavioural sciences, the relationship between predictor and criterion variables is often assumed to have a particular shape, such as monotone, single-peaked or U-shaped. Such assumptions can be transformed into (local or global) constraints on the sign of the nth-order derivative of the functional form. To check for such assumptions, we present a non-parametric regression method, P-splines regression, with additional asymmetric discrete penalties enforcing the constraints. We show that the corresponding loss function is convex and present a Newton-Raphson algorithm to optimize. Constrained P-splines are illustrated with an application on monotonicity-constrained regression with both one and two predictor variables, using data from research on the cognitive development of children.
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