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Xiu S, Wang X, Wang Q, Jin H, Shen Y. Impact of implementing a free varicella vaccination policy on incidence in Wuxi City, China: an interrupted time series analysis. Epidemiol Infect 2023; 151:e125. [PMID: 37469289 PMCID: PMC10540171 DOI: 10.1017/s0950268823001152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/08/2023] [Accepted: 07/05/2023] [Indexed: 07/21/2023] Open
Abstract
Varicella vaccination is optional and requires self-payment. On 1 December 2018, Wuxi City launched a free varicella vaccination program for children. This study aimed to evaluate the changes in varicella incidence before and after the implementation of the policy. The data were obtained from official information systems and statistical yearbooks. We divided the period into chargeable (January 2017 to November 2018) and free (December 2018 to December 2021) periods. Interrupt time series analysis was used to conduct a generalised least-squares regression analysis for the two periods. A total of 51,071 varicella cases were reported between January 2017 and December 2021. After the implementation of the policy, there was a statistically significant decrease in the incidence of varicella (β2 = -0.140, P = 0.017), and the slope of the incidence also decreased by 0.012 (P = 0.015). Following policy implementation, the incidence decreased in all age groups, with the largest decline observed among children aged 8-14 years (β2 = -1.109, P = 0.009), followed by children aged ≤7 years (β2 = -0.894, P = 0.013). Our study found a significant reduction in the incidence of varicella in the total population after the introduction of free varicella vaccination in Wuxi City.
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Affiliation(s)
- Shixin Xiu
- Department of Immunization, Wuxi Center for Disease Control and Prevention, Wuxi, China
| | - Xuwen Wang
- Department of Immunization, Wuxi Center for Disease Control and Prevention, Wuxi, China
| | - Qiang Wang
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, China
| | - Hui Jin
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, China
- Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, China
| | - Yuan Shen
- Department of Immunization, Wuxi Center for Disease Control and Prevention, Wuxi, China
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2
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Jansen MHA, Rondaan C, Legger GE, Minden K, Uziel Y, Toplak N, Maritsi D, van den Berg L, Berbers GAM, Bruijning P, Egert Y, Normand C, Bijl M, Foster HE, Koné-Paut I, Wouters C, Ravelli A, Elkayam O, Wulffraat NM, Heijstek MW. EULAR/PRES recommendations for vaccination of paediatric patients with autoimmune inflammatory rheumatic diseases: update 2021. Ann Rheum Dis 2023; 82:35-47. [PMID: 35725297 DOI: 10.1136/annrheumdis-2022-222574] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/24/2022] [Indexed: 02/03/2023]
Abstract
OBJECTIVES Recent insights supporting the safety of live-attenuated vaccines and novel studies on the immunogenicity of vaccinations in the era of biological disease-modifying antirheumatic drugs in paediatric patients with autoimmune/inflammatory rheumatic diseases (pedAIIRD) necessitated updating the EULAR recommendations. METHODS Recommendations were developed using the EULAR standard operating procedures. Two international expert committees were formed to update the vaccination recommendations for both paediatric and adult patients with AIIRD. After a systematic literature review, separate recommendations were formulated for paediatric and adult patients. For pedAIIRD, six overarching principles and seven recommendations were formulated and provided with the level of evidence, strength of recommendation and Task Force level of agreement. RESULTS In general, the National Immunisation Programmes (NIP) should be followed and assessed yearly by the treating specialist. If possible, vaccinations should be administered prior to immunosuppressive drugs, but necessary treatment should never be postponed. Non-live vaccines can be safely given to immunosuppressed pedAIIRD patients. Mainly, seroprotection is preserved in patients receiving vaccinations on immunosuppression, except for high-dose glucocorticoids and B-cell depleting therapies. Live-attenuated vaccines should be avoided in immunosuppressed patients. However, it is safe to administer the measles-mumps-rubella booster and varicella zoster virus vaccine to immunosuppressed patients under specific conditions. In addition to the NIP, the non-live seasonal influenza vaccination should be strongly considered for immunosuppressed pedAIIRD patients. CONCLUSIONS These recommendations are intended for paediatricians, paediatric rheumatologists, national immunisation agencies, general practitioners, patients and national rheumatology societies to attain safe and effective vaccination and optimal infection prevention in immunocompromised pedAIIRD patients.
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Affiliation(s)
- Marc H A Jansen
- Department of Paediatric Immunology & Rheumatology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands .,RITA, European Reference Networks, Brussels, Belgium
| | - Christien Rondaan
- Department of Medical Microbiology and Infection Prevention, University Medical Centre Groningen, Groningen, The Netherlands
| | - Geertje E Legger
- RITA, European Reference Networks, Brussels, Belgium.,Department of Paediatric Rheumatology, Beatrix Children's Hospital, University Medical Center Groningen, Groningen, The Netherlands
| | - Kirsten Minden
- Department of Pediatric Respiratory Medicine, Immunology and Critical Care Medicine, Charité Universitätsmedizin, Berlin, Germany.,Epidemiology Unit, German Rheumatism Research Centre, Berlin, Germany
| | - Yosef Uziel
- Paediatric Rheumatology Unit, Department of Paediatrics, Meir Medical Center, Kfar Saba, Israel
| | - Natasa Toplak
- RITA, European Reference Networks, Brussels, Belgium.,Department of Allergology, Rheumatology and Clinical Immunology, University Children's Hospital, Ljubljana, Slovenia
| | - Despoina Maritsi
- Infectious Diseases, Immunology and Rheumatology Unit, Department of Paediatrics, Kyriakou Children's Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Lotte van den Berg
- Dutch JIA Patient and Parent Organisation (JVN), Member of ENCA, Amsterdam, The Netherlands
| | - Guy A M Berbers
- Centre for Infectious Disease Control Netherlands, Laboratory for Infectious Diseases and Screening, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Patricia Bruijning
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Yona Egert
- European Network Childhood Arthritis (ENCA) Patient Organisation, Judea and Samaria Area, Israel
| | - Christophe Normand
- MCI Secretariat, European Network for Children with Arthritis (ENCA), Geneva, Switzerland
| | - Marc Bijl
- Department of Internal Medicine and Rheumatology, Martini Hospital Groningen, Groningen, The Netherlands
| | - Helen E Foster
- Population and Health Institute, Newcastle University, Newcastle upon Tyne, UK
| | - Isabelle Koné-Paut
- Department of Paediatric Rheumatology and CEREMAIA, Hôpital Bicêtre, AP HP, Université Paris Saclay, Paris, France
| | - Carine Wouters
- Division of Paediatric Rheumatology, University Hospitals Leuven, Leuven, Belgium
| | - Angelo Ravelli
- RITA, European Reference Networks, Brussels, Belgium.,Department of Rheumatology, Direzione Scientifica, IRCCS Istituto Giannina Gaslini, Genova, Italy.,Dipartimento di Neuroscienze, Riabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili (DINOGMI), Università degli Studi di Genova, Genoa, Italy
| | - Ori Elkayam
- Department of Rheumatology, Tel Aviv Sourasky Medical Center and the Sackler faculty of medicine, Tel Aviv University, Tel Aviv, Israel
| | - Nicolaas M Wulffraat
- Department of Paediatric Immunology & Rheumatology, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, The Netherlands.,RITA, European Reference Networks, Brussels, Belgium
| | - Marloes W Heijstek
- RITA, European Reference Networks, Brussels, Belgium.,Department of Rheumatology & Clinical Immunology, University Medical Center Utrecht, Utrecht, The Netherlands
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3
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Anderson R, Kim S, Roberts N, Petrou S. Systematic review of economic evaluations of varicella vaccination programmes. PLoS One 2023; 18:e0282327. [PMID: 36972249 PMCID: PMC10042376 DOI: 10.1371/journal.pone.0282327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 02/14/2023] [Indexed: 03/29/2023] Open
Abstract
OBJECTIVES This study carried out a systematic literature review of economic evaluations of varicella vaccination programmes from the earliest publication to the present day, including programmes in the workplace and in special risk groups as well as universal childhood vaccination and catch up programmes. METHODS Articles published from 1985 until 2022 were sourced from PubMed/Medline, Embase, Web of Science, NHSEED and Econlit. Eligible economic evaluations, which included posters and conference abstracts, were identified by two reviewers who scrutinised each other's selections at both title and abstract and full report stages. The studies are described in terms of their methodological characteristics. Their results are aggregated by type of vaccination programme and the nature of the economic outcome. RESULTS A total of 2575 articles were identified of which 79 qualified as economic evaluations. A total of 55 studies focused on universal childhood vaccination, 10 on the workplace and 14 on high risk groups. Twenty-seven studies reported estimates of incremental cost per quality-adjusted life year (QALY) gained, 16 reported benefit-cost ratios, 20 reported cost-effectiveness outcomes in terms of incremental cost per event or life saved and 16 reported cost-cost offset results. Most studies of universal childhood vaccination reported an increase in overall costs to health services, but often a reduction in cost from a societal perspective. CONCLUSIONS The evidence surrounding the cost-effectiveness of varicella vaccination programmes remains sparse with contrasting conclusions in some areas. Future research should particularly aim to encompass the impact of universal childhood vaccination programmes on herpes zoster among adults.
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Affiliation(s)
- Robert Anderson
- Centre for Health Service Economics and Organisation, Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Sungwook Kim
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
| | - Nia Roberts
- Health Care Libraries, Bodleian Libraries, University of Oxford, Oxford, United Kingdom
| | - Stavros Petrou
- Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom
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Bozzola E, Marchesani S, Ficari A, Brusco C, Spina G, Marchili MR, Guolo S. Assessing the use of antibiotics in pediatric patients hospitalized for varicella. Ital J Pediatr 2022; 48:196. [PMID: 36503563 PMCID: PMC9743721 DOI: 10.1186/s13052-022-01393-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 11/29/2022] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Varicella is considered a mild and self-limiting disease, but, in some cases, it may complicate and require hospitalization. Antibiotics are not the first line therapy but in some cases are prescribed either for the management of varicella-related complications or as a preventive strategy. Aim of this study is to analyze the rate and the patterns of antibiotics used in pediatric patients hospitalized for varicella as well as the relative costs in order to increase insights in antibiotic use in varicella. METHODS Patients less than 18 years hospitalized for varicella at the Bambino Gesù Children's IRCCS Hospital in Rome, Italy, from the 1st of November 2005 to the 1st of November 2021 entered the study. Retrospective data were collected from the hospital's database electronic medical records. The rate, the patterns and the costs of antibiotics used were considered. RESULTS According to the inclusion criteria, we enrolled 810 patients, with a median age of 2.4 years. Out of them, 345 patients (42.6%) underwent antibiotic therapy, of which 307 for a complication (90.0%) and the other 10.0%, antibiotic for the fear of developing complications. The cost for varicella hospitalizations was EUR 2,928,749 (median cost EUR 2689). As for antibiotic therapy, it represented the 5.9% of the total cost (EUR 174,527), with a median cost of EUR 198.8. The cost in patients who underwent antibiotic therapy was significantly higher than in those who did not (p-value < 0.0001), as well as the hospitalization length (p-value < 0.0001). The most commonly prescribed antibiotics were Amoxicillin-clavulanate and Ceftriaxone, which represented the 36.0% and 25.0% of all antibiotic prescription, respectively. Antibiotics may negatively affect the economic cost of hospitalization and the prescription is not always in accordance to guidelines, with potential important repercussions on the development of antimicrobial resistance. Actually, resistance to antibiotics is considered a major risk to the future health of the world population as it may lead to longer hospital stay, increased risk of mortality, health care costs and treatment failures. CONCLUSION Strategies to reduce economical cost, hospitalization length and antimicrobial resistance include ensuring appropriate prescription and administration of empiric antibiotics as well as reducing the circulation of preventable infectious diseases through immunization.
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Affiliation(s)
- Elena Bozzola
- grid.414125.70000 0001 0727 6809Pediatric Unit, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy
| | - Silvio Marchesani
- grid.414125.70000 0001 0727 6809Pediatric Unit, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy
| | - Andrea Ficari
- grid.414125.70000 0001 0727 6809Pediatric Unit, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy
| | - Carla Brusco
- grid.414125.70000 0001 0727 6809Sanitary Direction Unit, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy
| | - Giulia Spina
- grid.414125.70000 0001 0727 6809Pediatric Unit, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy
| | - Maria Rosaria Marchili
- grid.414125.70000 0001 0727 6809Pediatric Unit, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy
| | - Stefano Guolo
- grid.414125.70000 0001 0727 6809Sanitary Direction Unit, Bambino Gesù Children’s Hospital IRCCS, Rome, Italy
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Pillsbury M, Carias C, Samant S, Greenberg D, Pawaskar M. Comparison of performance of varicella vaccines via infectious disease modeling. Vaccine 2022; 40:3954-3962. [PMID: 35660037 DOI: 10.1016/j.vaccine.2022.05.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 04/06/2022] [Accepted: 05/03/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND Population-level infectious disease models for varicella require vaccine parameters, namely 'take' and 'duration of protection' (defined here as vaccine performance), to quantify the impact of vaccination. Current published models for varicella use vaccine parameters derived from various methodologies which does not allow for the direct comparison of different vaccines. METHODS We estimated take and duration of protection using deterministic compartmental models to simulate clinical trials of one- or two-dose varicella vaccination using Varivax® (V-MSD) and Varilrix® (V-GSK). We fit different models to clinical trial data on breakthrough infections and evaluated their respective goodness-of-fit using the Akaike Information Criterion (AIC). RESULTS Based upon the clinical trial data, we estimated that 90.3% (95% CI: 87.8-92.9%) of the cohort gained permanent protection from breakthrough varicella after the first dose of V-MSD compared to 61.7% (95% CI: 58.2-65.3%) with the first dose of V-GSK. We further estimated that a total of 97.0% (95% CI: 95.2-98.8%) and 93.8% (95% CI: 92.2-95.4%) of the cohort were permanently protected after two-doses of V-MSD and V-GSK, respectively. According to the AIC, our new model (V-MSD AIC = 92.7; V-GSK AIC = 170.3) provided a better fit than an existing model (V-MSD AIC = 108.9; V-GSK AIC = 216.1). CONCLUSIONS The model developed fits the long-term clinical trial data on breakthrough infections for both V-MSD and V-GSK, thus, allowing for the direct comparison of vaccine performance. We estimated that a single dose of V-MSD was more likely to provide permanent protection than a single dose of V-GSK, while the protection offered by two doses was similar for both vaccines.
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Affiliation(s)
- Matthew Pillsbury
- Center for Observational and Real-World Evidence (CORE), Merck & Co., Inc., Kenilworth, NJ, USA
| | - Cristina Carias
- Center for Observational and Real-World Evidence (CORE), Merck & Co., Inc., Kenilworth, NJ, USA
| | - Salome Samant
- Center for Observational and Real-World Evidence (CORE), Merck & Co., Inc., Kenilworth, NJ, USA
| | - David Greenberg
- Ben Gurion University. Division of Pediatrics, Beer-Sheva, Israel
| | - Manjiri Pawaskar
- Center for Observational and Real-World Evidence (CORE), Merck & Co., Inc., Kenilworth, NJ, USA.
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6
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Pawaskar M, Fergie J, Harley C, Samant S, Veeranki P, Diaz O, Conway JH. Impact of universal varicella vaccination on the use and cost of antibiotics and antivirals for varicella management in the United States. PLoS One 2022; 17:e0269916. [PMID: 35687559 PMCID: PMC9187103 DOI: 10.1371/journal.pone.0269916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 05/31/2022] [Indexed: 11/19/2022] Open
Abstract
Background
Our objective was to estimate the impact of universal varicella vaccination (UVV) on the use and costs of antibiotics and antivirals for the management of varicella among children in the United States (US).
Methods
A decision tree model of varicella vaccination, infections and treatment decisions was developed. Results were extrapolated to the 2017 population of 73.5 million US children. Model parameters were populated from published sources. Treatment decisions were derived from a survey of health care professionals’ recommendations. The base case modelled current vaccination coverage rates in the US with additional scenarios analyses conducted for 0%, 20%, and 80% coverage and did not account for herd immunity benefits.
Results
Our model estimated that 551,434 varicella cases occurred annually among children ≤ 18 years in 2017. Antivirals or antibiotics were prescribed in 23.9% of cases, with unvaccinated children receiving the majority for base case. The annual cost for varicella antiviral and antibiotic treatment was approximately $14 million ($26 per case), with cases with no complications accounting for $12 million. Compared with the no vaccination scenario, the current vaccination rates resulted in savings of $181 million (94.7%) for antivirals and $78 million (95.0%) for antibiotics annually. Scenario analyses showed that higher vaccination coverage (from 0% to 80%) resulted in reduced annual expenditures for antivirals (from $191 million to $41 million), and antibiotics ($82 million to $17 million).
Conclusions
UVV was associated with significant reductions in the use of antibiotics and antivirals and their associated costs in the US. Higher vaccination coverage was associated with lower use and costs of antibiotics and antivirals for varicella management.
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Affiliation(s)
- Manjiri Pawaskar
- Merck & Co. Inc., Rahway, New Jersey, United States of America
- * E-mail:
| | - Jaime Fergie
- Driscoll Children’s Hospital, Corpus Christi, Texas, United States of America
| | - Carolyn Harley
- PRECISIONheor, Los Angeles, California, United States of America
| | - Salome Samant
- Merck & Co. Inc., Rahway, New Jersey, United States of America
| | - Phani Veeranki
- PRECISIONheor, Los Angeles, California, United States of America
| | - Oliver Diaz
- PRECISIONheor, Los Angeles, California, United States of America
| | - James H. Conway
- School of Medicine and Public Health, University of Wisconsin, Madison, Wisconsin, United States of America
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Pawaskar M, Méroc E, Samant S, Flem E, Bencina G, Riera-Montes M, Heininger U. Economic burden of varicella in Europe in the absence of universal varicella vaccination. BMC Public Health 2021; 21:2312. [PMID: 34930179 PMCID: PMC8690977 DOI: 10.1186/s12889-021-12343-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 11/26/2021] [Indexed: 11/29/2022] Open
Abstract
Background Though the disease burden of varicella in Europe has been reported previously, the economic burden is still unknown. This study estimated the economic burden of varicella in Europe in the absence of Universal Varicella Vaccination (UVV) in 2018 Euros from both payer (direct costs) and societal (direct and indirect costs) perspectives. Methods We estimated the country specific and overall annual costs of varicella in absence of UVV in 31 European countries (27 EU countries, plus Iceland, Norway, Switzerland and the United Kingdom). To obtain country specific unit costs and associated healthcare utilization, we conducted a systematic literature review, searching in PubMed, EMBASE, NEED, DARE, REPEC, Open Grey, and public heath websites (1/1/1999–10/15/2019). The number of annual varicella cases, deaths, outpatient visits and hospitalizations were calculated (without UVV) based on age-specific incidence rates (Riera-Montes et al. 2017) and 2018 population data by country. Unit cost per varicella case and disease burden data were combined using stochastic modeling to estimate 2018 costs stratified by country, age and healthcare resource. Results Overall annual total costs associated with varicella were estimated to be €662,592,061 (Range: €309,552,363 to €1,015,631,760) in Europe in absence of UVV. Direct and indirect costs were estimated at €229,076,206 (Range €144,809,557 to €313,342,856) and €433,515,855 (Range €164,742,806 to €702,288,904), respectively. Total cost per case was €121.45 (direct: €41.99; indirect: €79.46). Almost half of the costs were attributed to cases in children under 5 years, owing mainly to caregiver work loss. The distribution of costs by healthcare resource was similar across countries. France and Germany accounted for 49.28% of total annual costs, most likely due to a combination of high numbers of cases and unit costs in these countries. Conclusions The economic burden of varicella across Europe in the absence of UVV is substantial (over 600 M€), primarily driven by caregiver burden including work productivity losses. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-021-12343-x.
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Affiliation(s)
- Manjiri Pawaskar
- Merck & Co., Inc. Center for Observational and Real-World Evidence, 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA.
| | - Estelle Méroc
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan 1, 3001, Leuven, Belgium
| | - Salome Samant
- Merck & Co., Inc. Center for Observational and Real-World Evidence, 2000 Galloping Hill Road, Kenilworth, NJ, 07033, USA
| | - Elmira Flem
- MSD (Norge) AS, Postboks 458 Brakerøya, 3002, Drammen, Norway
| | - Goran Bencina
- MSD, Calle de Josefa Valcárcel, 38, 28027, Madrid, Spain
| | - Margarita Riera-Montes
- P95 Epidemiology and Pharmacovigilance, Koning Leopold III laan 1, 3001, Leuven, Belgium
| | - Ulrich Heininger
- University of Basel Children's Hospital (UKBB), Spitalstrasse 33, 4056, Basel, Switzerland.,Faculty of Medicine, University of Basel, Klingelbergstrasse 61, 4056, Basel, Switzerland
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8
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Vandenhaute J, Tsakeu E, Chevalier P, Pawaskar M, Benčina G, Vertriest J. Assessing the use of antibiotics and the burden of varicella in Belgium using a retrospective GP database analysis. BMC Infect Dis 2021; 21:1150. [PMID: 34758734 PMCID: PMC8582146 DOI: 10.1186/s12879-021-06848-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 11/01/2021] [Indexed: 11/21/2022] Open
Abstract
Background Varicella is a highly contagious infection that typically occurs in childhood. While most cases have a generally benign outcome, infection results in a considerable healthcare burden and serious complications may occur. Objectives The objective of this study was to characterize the burden of varicella in a real-world primary care setting in Belgium, including the rate of varicella-related complications, medication management and general practitioner (GP) visits. Methods The study was a retrospective observational study using data from a longitudinal patient database in a primary care setting in Belgium. Patients with a GP visit and a varicella diagnosis between January 2016 and June 2019 were eligible and data one month prior and three months after the diagnosis were included. Outcomes included varicella-related complications, antibiotic use, antiviral use, and GP follow-up visits. Antibiotic use could be specified by class of antibiotic and linked to a diagnosis. Complications were identified based on concomitant diagnosis with varicella during the study period. Results 3,847 patients with diagnosis of varicella were included, with a mean age of 8.4 years and a comparable distribution of gender. 12.6% of patients with varicella had a concomitant diagnosis of a varicella-related complication. During the follow-up period, 27.3% of patients with varicella were prescribed antibiotics, either systemic (19.8%) and/or topical (10.3%). The highest rate of antibiotic prescriptions was observed in patients with complications (63.5%) and in patients younger than 1 year (41.8%). Nevertheless, 5.3% of the patients were prescribed antibiotics without a concomitant diagnosis of another infection. The most commonly prescribed systemic antibiotics were amoxicillin alone or combined with beta-lactamase inhibitor, and thiamphenicol. Fusidic acid and tobramycin were the most prescribed topical antibiotics. Antivirals were prescribed for 2.7% of the study population. 4.7% of the patients needed a follow-up visit with their GP. Conclusions This study reports a substantial burden of varicella in a primary care setting in Belgium, with high rates of complications and antibiotic use. Supplementary Information The online version contains supplementary material available at 10.1186/s12879-021-06848-4.
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Affiliation(s)
| | | | | | - Manjiri Pawaskar
- Center for Observational and Real-World Evidence, Merck & Co., Inc, Kenilworth, NJ, USA
| | | | - Jan Vertriest
- MSD, Clos du Lynx 5, Sint-Lambrechts-Woluwe, 1200, Brussels, Belgium
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Wang Q, Xiu S, Yang L, Huang J, Cui T, Shi N, Wang X, Shen Y, Chen E, Lu B, Jin H, Lin L. Economic evaluation of varicella vaccination strategies in Jiangsu province, China: a decision-tree Markov model. Hum Vaccin Immunother 2021; 17:4194-4202. [PMID: 34357833 DOI: 10.1080/21645515.2021.1958608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
Abstract
This study evaluated different varicella vaccination strategies in Jiangsu province, China. A decision-tree Markov model was used to evaluate the cost effectiveness of various varicella vaccination strategies for children, including direct and selective vaccination (serotesting pre-vaccination). A cohort of one-year-old children was followed through 60 one-year Markov cycles. The parameter estimation was based on field work, the literature, and statistical yearbooks. We calculated the incremental cost-utility ratio (ICUR) using the saved quality-adjusted life year (QALY). One-way and probability sensitivity analyses were performed to assess uncertainty. Among 100,000 cohort members, one-dose and two-dose direct vaccination averted 8061 and 10,701 varicella cases, respectively, compared with no vaccination. Furthermore, compared with no vaccination, one-dose and two-dose direct vaccination saved one QALY at the ICUR of USD 21,401.33 and USD 35,420.81, respectively, at less than three times the per capita gross domestic product (USD 47,626.86) of Jiangsu. The ICURs of the one-dose and two-dose selective strategies versus no vaccination were USD 42,623.62 and USD 51,406.35 per QALY gained, respectively. The cost effectiveness results were most sensitive to the QALY loss of outpatients and vaccine prices. Thus, in Jiangsu, one-dose and two-dose direct varicella vaccination in children could be cost effective at the willingness to pay threshold of three times provincial GDP per capita from a societal perspective. The findings were sensitive to the vaccine price and health utility of varicella cases.
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Affiliation(s)
- Qiang Wang
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Shixin Xiu
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Liuqing Yang
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Jinxin Huang
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Tingting Cui
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Naiyang Shi
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Xuwen Wang
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Yuan Shen
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Enpin Chen
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Bing Lu
- Department of Immunization Planning, Wuxi Center for Disease Control and Prevention, Wuxi, PR China
| | - Hui Jin
- Department of Epidemiology and Health Statistics, School of Public Health, Southeast University, Nanjing, PR China.,Key Laboratory of Environmental Medicine Engineering, Ministry of Education, School of Public Health, Southeast University, Nanjing, PR China
| | - Leesa Lin
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.,Laboratory of Data Discovery for Health (D24H), Hong Kong Science Park, Hong Kong, China
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Boersma C, Postma MJ. Health Economics of Vaccines: From Current Practice to Future Perspectives. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2021; 24:1-2. [PMID: 33431140 PMCID: PMC7733792 DOI: 10.1016/j.jval.2020.11.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Accepted: 11/20/2020] [Indexed: 05/05/2023]
Affiliation(s)
- Cornelis Boersma
- Department of Health Sciences, University of Groningen, University Medical Center Groningen, The Netherlands; Department of Management Sciences, Open University The Netherlands, Heerlen, The Netherlands; Health-Ecore Ltd, Zeist, The Netherlands
| | - Maarten J Postma
- Department of Health Sciences, University of Groningen, University Medical Center Groningen, The Netherlands; Health-Ecore Ltd, Zeist, The Netherlands; Department of Pharmacy, University of Groningen, Groningen, The Netherlands; Department of Economics, Econometrics and Finance, University of Groningen, Groningen, The Netherlands; Department of Pharmacology and Therapy, Universitas Airlangga, Surabaya, Indonesia; Center of Excellence in Higher Education for Pharmaceutical Care Innovation, Universitas Padjadjaran, Bandung, Indonesia.
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11
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Rafferty ERS, McDonald W, Osgood ND, Doroshenko A, Farag M. What We Know Now: An Economic Evaluation of Chickenpox Vaccination and Dose Timing Using an Agent-Based Model. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2021; 24:50-60. [PMID: 33431153 DOI: 10.1016/j.jval.2020.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 09/03/2020] [Accepted: 10/05/2020] [Indexed: 06/12/2023]
Abstract
OBJECTIVES The value of chickenpox vaccination is still debated in the literature and by jurisdictions worldwide. This uncertainty is reflected in the inconsistent uptake of the vaccine, where some countries offer routine childhood immunization programs, others have targeted programs, and in many the vaccine is only privately available. Even across the countries that have universal funding for the vaccine, there is a diversity of schedules and dosing intervals. Using an agent-based model of chickenpox and shingles, we conducted an economic evaluation of chickenpox vaccination in Alberta, Canada. METHODS We compared the cost-effectiveness of 2 common chickenpox vaccination schedules, specifically a long dosing interval (first dose: 12 months; second dose: 4-6 years) and a short dosing interval (first dose: 12 months; second dose: 18 months). RESULTS The economic evaluation demonstrated a shorter dosing interval may be marginally preferred, although it consistently led to higher costs from both the societal and healthcare perspectives. We found that chickenpox vaccination would be cost-saving and highly cost-effective from the societal and healthcare perspective, assuming there was no impact on shingles. CONCLUSION Chickenpox vaccine was cost-effective when not considering shingles and remained so even if there was a minor increase in shingles following vaccination. However, if chickenpox vaccination did lead to a substantial increase in shingles, then chickenpox vaccination was not cost-effective from the healthcare perspective.
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Affiliation(s)
- Ellen R S Rafferty
- School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; Faculty of Nursing, Edmonton Clinic Health Academy, University of Alberta, Edmonton, Alberta, Canada.
| | - Wade McDonald
- Department of Computer Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Nathaniel D Osgood
- Department of Computer Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
| | - Alexander Doroshenko
- Faculty of Medicine and Dentistry, Department of Medicine, Division of Preventive Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Marwa Farag
- School of Public Health, University of Saskatchewan, Saskatoon, Saskatchewan, Canada; School of Public Administration and Development Economics, Doha Institute for Graduate Studies, Doha, Qatar
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12
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Graham J, Wolfson LJ, Kyle J, Bolde-Villarreal CP, Guarneros-DeRegil DB, Monsanto H, Pillsbury M, Talbird S, Daniels VJ. Budget impact analysis of multiple varicella vaccination strategies: a Mexico perspective. Hum Vaccin Immunother 2019; 16:886-894. [PMID: 31567045 PMCID: PMC7227656 DOI: 10.1080/21645515.2019.1672491] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
A number of live-attenuated varicella vaccines are produced globally that provide protection against the varicella zoster virus. In Mexico, varicella vaccination is not included in the national immunization program and is recommended for use only in high-risk subgroups. We developed a budget impact model to estimate the impact of universal childhood immunization against varicella on the national payer system in Mexico. A scenario of no varicella vaccination was compared to scenarios with vaccination with a single dose at 13 months of age, in alignment with the existing program of immunization with the measles-mumps-rubella vaccine. Nine different vaccination scenarios were envisioned, differing by vaccine type and by coverage. Varicella cases and treatment costs of each scenario were computed in a dynamic transmission model of varicella epidemiology, calibrated to the population of Mexico. Unit costs were based on Mexico sources or were from the literature. The results indicated that each of the three vaccine types increased vaccine acquisition and administration expenditures but produced overall cost savings in each of the first 10 years of the program, due to fewer cases and reduced varicella treatment costs. A highly effective vaccine at 95% coverage produced the greatest cost savings.
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Affiliation(s)
- Jonathan Graham
- Health Economics, Research Triangle Park, RTI Health Solutions, NC, USA
| | - Lara J Wolfson
- Center for Observational and Real World Evidence (CORE), Merck & Co., Inc, Kenilworth, NJ, USA
| | - Jeffrey Kyle
- Center for Observational and Real World Evidence (CORE), Merck & Co., Inc, Kenilworth, NJ, USA
| | | | | | | | - Matthew Pillsbury
- Center for Observational and Real World Evidence (CORE), Merck & Co., Inc, Kenilworth, NJ, USA
| | - Sandra Talbird
- Health Economics, Research Triangle Park, RTI Health Solutions, NC, USA
| | - Vincent J Daniels
- Center for Observational and Real World Evidence (CORE), Merck & Co., Inc, Kenilworth, NJ, USA
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13
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Leidner AJ, Murthy N, Chesson HW, Biggerstaff M, Stoecker C, Harris AM, Acosta A, Dooling K, Bridges CB. Cost-effectiveness of adult vaccinations: A systematic review. Vaccine 2018; 37:226-234. [PMID: 30527660 DOI: 10.1016/j.vaccine.2018.11.056] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/29/2018] [Accepted: 11/16/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND Coverage levels for many recommended adult vaccinations are low. The cost-effectiveness research literature on adult vaccinations has not been synthesized in recent years, which may contribute to low awareness of the value of adult vaccinations and to their under-utilization. We assessed research literature since 1980 to summarize economic evidence for adult vaccinations included on the adult immunization schedule. METHODS We searched PubMed, EMBASE, EconLit, and Cochrane Library from 1980 to 2016 and identified economic evaluation or cost-effectiveness analysis for vaccinations targeting persons aged ≥18 years in the U.S. or Canada. After excluding records based on title and abstract reviews, the remaining publications had a full-text review from two independent reviewers, who extracted economic values that compared vaccination to "no vaccination" scenarios. RESULTS The systematic searches yielded 1688 publications. After removing duplicates, off-topic publications, and publications without a "no vaccination" comparison, 78 publications were included in the final analysis (influenza = 25, pneumococcal = 18, human papillomavirus = 9, herpes zoster = 7, tetanus-diphtheria-pertussis = 9, hepatitis B = 9, and multiple vaccines = 1). Among outcomes assessing age-based vaccinations, the percent indicating cost-savings was 56% for influenza, 31% for pneumococcal, and 23% for tetanus-diphtheria-pertussis vaccinations. Among age-based vaccination outcomes reporting $/QALY, the percent of outcomes indicating a cost per QALY of ≤$100,000 was 100% for influenza, 100% for pneumococcal, 69% for human papillomavirus, 71% for herpes zoster, and 50% for tetanus-diphtheria-pertussis vaccinations. CONCLUSIONS The majority of published studies report favorable cost-effectiveness profiles for adult vaccinations, which supports efforts to improve the implementation of adult vaccination recommendations.
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Affiliation(s)
| | - Neil Murthy
- National Center for Immunization and Respiratory Diseases, CDC, USA; Epidemic Intelligence Service, CDC, USA
| | - Harrell W Chesson
- National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC, USA
| | | | - Charles Stoecker
- School of Public Health and Tropical Medicine, Tulane University, USA
| | - Aaron M Harris
- National Center for HIV/AIDS, Viral Hepatitis, STD, and TB Prevention, CDC, USA
| | - Anna Acosta
- National Center for Immunization and Respiratory Diseases, CDC, USA
| | - Kathleen Dooling
- National Center for Immunization and Respiratory Diseases, CDC, USA
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14
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Drolet M, Bénard É, Jit M, Hutubessy R, Brisson M. Model Comparisons of the Effectiveness and Cost-Effectiveness of Vaccination: A Systematic Review of the Literature. VALUE IN HEALTH : THE JOURNAL OF THE INTERNATIONAL SOCIETY FOR PHARMACOECONOMICS AND OUTCOMES RESEARCH 2018; 21:1250-1258. [PMID: 30314627 DOI: 10.1016/j.jval.2018.03.014] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 03/20/2018] [Accepted: 03/25/2018] [Indexed: 05/21/2023]
Abstract
OBJECTIVES To describe all published articles that have conducted comparisons of model-based effectiveness and cost-effectiveness results in the field of vaccination. Specific objectives were to 1) describe the methodologies used and 2) identify the strengths and limitations of the studies. METHODS We systematically searched MEDLINE and Embase databases for studies that compared predictions of effectiveness and cost-effectiveness of vaccination of two or more mathematical models. We categorized studies into two groups on the basis of their data source for comparison (previously published results or new simulation results) and performed a qualitative synthesis of study conclusions. RESULTS We identified 115 eligible articles (only 5% generated new simulations from the reviewed models) examining the effectiveness and cost-effectiveness of vaccination against 14 pathogens (69% of studies examined human papillomavirus, influenza, and/or pneumococcal vaccines). The goal of most of studies was to summarize evidence for vaccination policy decisions, and cost-effectiveness was the most frequent outcome examined. Only 33%, 25%, and 3% of studies followed a systematic approach to identify eligible studies, assessed the quality of studies, and performed a quantitative synthesis of results, respectively. A greater proportion of model comparisons using published studies followed a systematic approach to identify eligible studies and to assess their quality, whereas more studies using new simulations performed quantitative synthesis of results and identified drivers of model conclusions. Most comparative modeling studies concluded that vaccination was cost-effective. CONCLUSIONS Given the variability in methods used to conduct/report comparative modeling studies, guidelines are required to enhance their quality and transparency and to provide better tools for decision making.
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Affiliation(s)
- Mélanie Drolet
- Centre de recherche du CHU de Québec-Université Laval, Axe santé des populations et pratiques optimales en santé, Québec, Canada
| | - Élodie Bénard
- Centre de recherche du CHU de Québec-Université Laval, Axe santé des populations et pratiques optimales en santé, Québec, Canada
| | - Mark Jit
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, UK; Modelling and Economics Unit, Public Health England, London, UK
| | | | - Marc Brisson
- Centre de recherche du CHU de Québec-Université Laval, Axe santé des populations et pratiques optimales en santé, Québec, Canada; Université Laval, Québec, Canada; Department of Infectious Disease Epidemiology, Imperial College, London, UK.
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15
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Wysocki J, Malecka I, Stryczynska-Kazubska J, Rampakakis E, Kuter B, Wolfson LJ. Varicella in Poland: economic burden in children 1-12 years of age in Poland, 2010-2015. BMC Public Health 2018; 18:410. [PMID: 29587714 PMCID: PMC5870512 DOI: 10.1186/s12889-018-5298-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Accepted: 03/12/2018] [Indexed: 11/21/2022] Open
Abstract
Background The safety and efficacy of live-attenuated varicella zoster virus (VZV) vaccines in preventing varicella and reducing associated morbidity and mortality in real-world have been previously shown. In Poland, VZV vaccination is only mandatory for certain high-risk individuals. Here, we have conducted an evaluation of the clinical and economic burden of varicella in Poland. Methods Multicenter, retrospective chart review of varicella inpatients and outpatients aged 1–12 years with a primary diagnosis between 2010 and 2015. Varicella-related outcomes included the incidence of complications, the proportion of patients reporting healthcare resource utilization (HCRU), and frequency of HCRU. Direct costs were derived from per patient resource use multiplied by unit costs, and indirect costs were calculated as loss of revenue of caregivers reporting work days missed. The overall annual cost of varicella in Poland was estimated based on the calculated direct and indirect costs per case and the estimated number of varicella cases. All costs are presented in 2015 Polish złoty (PLN) / Euros (€). Results A total of 150 children with varicella were included, of which 75 were outpatients and 75 were inpatients with a mean (± SD) age of 3.9 (±2.6) and 4.2 (±2.3) years, respectively. Complications were experienced by 14.7% of outpatients and 82.7% of inpatients, of which the most common were skin and soft tissue infections and dehydration. The rate of HCRU was as follows: over-the-counter medications (80.0% outpatients, 81.3% inpatients), prescription medications (80.0% outpatients, 93.3% inpatients), tests/procedures (0.0% outpatients, 69.3% inpatients), and allied health professional consults (0.0% outpatients, 24.0% inpatients). Total (direct and indirect) cost per varicella case was 5013.3 PLN (€ 1198.1) for inpatients and 1027.2 PLN (€ 245.5) for outpatients, resulting in an estimated overall annual (2015) cost of varicella in Poland of 178,198,320 PLN (€ 42,588,385) among children aged 1–15 years. Conclusions Significant clinical and economic burden is associated with varicella in Poland. These results may be used to foster discussion related to the implications of implementing routine VZV vaccination in Poland.
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Affiliation(s)
- Jacek Wysocki
- Poznan University of Medical Sciences, Collegium Maius, Fredry 10, 61-701, Poznań, Poland
| | - Ilona Malecka
- Poznan University of Medical Sciences, Collegium Maius, Fredry 10, 61-701, Poznań, Poland
| | | | | | - Barbara Kuter
- Merck & Co., Inc., 2000 Galloping Hill Rd, Kenilworth, NJ, 07033, USA
| | - Lara J Wolfson
- Merck & Co., Inc., 2000 Galloping Hill Rd, Kenilworth, NJ, 07033, USA.
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17
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Jit M, Hutubessy R. Methodological Challenges to Economic Evaluations of Vaccines: Is a Common Approach Still Possible? APPLIED HEALTH ECONOMICS AND HEALTH POLICY 2016; 14:245-52. [PMID: 26832145 PMCID: PMC4871927 DOI: 10.1007/s40258-016-0224-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Economic evaluation of vaccination is a key tool to inform effective spending on vaccines. However, many evaluations have been criticised for failing to capture features of vaccines which are relevant to decision makers. These include broader societal benefits (such as improved educational achievement, economic growth and political stability), reduced health disparities, medical innovation, reduced hospital beds pressures, greater peace of mind and synergies in economic benefits with non-vaccine interventions. Also, the fiscal implications of vaccination programmes are not always made explicit. Alternative methodological frameworks have been proposed to better capture these benefits. However, any broadening of the methodology for economic evaluation must also involve evaluations of non-vaccine interventions, and hence may not always benefit vaccines given a fixed health-care budget. The scope of an economic evaluation must consider the budget from which vaccines are funded, and the decision-maker's stated aims for that spending to achieve.
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Affiliation(s)
- Mark Jit
- Modelling and Economics Unit, Public Health England, 61 Colindale Avenue, London, NW9 6BT, UK.
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, Keppel Street, London, WC1E 7HT, UK.
| | - Raymond Hutubessy
- Initiative for Vaccine Research, World Health Organization, 20 Avenue Appia, 1211, Geneva 27, Switzerland
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Nagaoka K, Fujiwara T. Impact of Subsidies and Socioeconomic Status on Varicella Vaccination in Greater Tokyo, Japan. Front Pediatr 2016; 4:19. [PMID: 27014669 PMCID: PMC4791386 DOI: 10.3389/fped.2016.00019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 02/29/2016] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Although the control of varicella outbreaks is an important health issue, cost could present a major barrier for vaccination. The aim of this study is to investigate the association of vaccine subsidies and caregivers' socioeconomic status with varicella vaccine coverage of their children in Greater Tokyo, Japan, before the period that varicella vaccination was included in routine immunization program. METHODS Participants were recruited from two different cities. In Chiba city, parents of 18-month-old infants (N = 378) undergoing a medical examination in July 2013 were recruited at a clinic where no subsidy for varicella immunization was provided. In Nishitokyo city, parents of 24- to 30-month-old children (N = 315) undergoing a health checkup in July and August 2013 were recruited at a clinic where a partial subsidy was provided. The association between household income and varicella immunization was investigated by multivariate logistic regression stratified by city. RESULTS Vaccine coverage was 61.0% in Chiba city and 73.3% in Nishitokyo city. In Chiba city, odds ratios of middle and high household income for varicella immunization were 4.22 [95% confidence interval (CI): 1.65-10.7] and 5.94 (95% CI: 1.89-18.6), respectively, compared to low household income. However, household income was not associated with varicella vaccination in Nishitokyo city. Neither working status nor education was associated with vaccination in both cities. CONCLUSION While household income was associated with high vaccine coverage in the city with no vaccine subsidy, this association was not observed in the city where the subsidy was given, which suggests that cost is a barrier for varicella immunization. Thus, in countries where varicella vaccination is not included in routine immunization programs, introducing subsidies nationwide or routine immunization programs for varicella vaccination would be an important approach to eliminate inequality in vaccine coverage.
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Affiliation(s)
- Kei Nagaoka
- Department of Social Medicine, National Research Institute for Child Health and Development , Tokyo , Japan
| | - Takeo Fujiwara
- Department of Social Medicine, National Research Institute for Child Health and Development , Tokyo , Japan
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van Lier A, Lugnér A, Opstelten W, Jochemsen P, Wallinga J, Schellevis F, Sanders E, de Melker H, van Boven M. Distribution of Health Effects and Cost-effectiveness of Varicella Vaccination are Shaped by the Impact on Herpes Zoster. EBioMedicine 2015; 2:1494-9. [PMID: 26629544 PMCID: PMC4634630 DOI: 10.1016/j.ebiom.2015.08.017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 08/07/2015] [Accepted: 08/07/2015] [Indexed: 02/06/2023] Open
Abstract
Introduction Varicella zoster virus (VZV) is the etiological agent of varicella and herpes zoster (HZ). It has been hypothesised that immune boosting of latently infected persons by contact with varicella reduces the probability of HZ. If true, universal varicella vaccination may increase HZ incidence due to reduced VZV circulation. To inform decision-making, we conduct cost-effectiveness analyses of varicella vaccination, including effects on HZ. Methods Effects of varicella vaccination are simulated with a dynamic transmission model, parameterised with Dutch VZV seroprevalence and HZ incidence data, and linked to an economic model. We consider vaccination scenarios that differ by whether or not they include immune boosting, and reactivation of vaccine virus. Results Varicella incidence decreases after introduction of vaccination, while HZ incidence may increase or decrease depending on whether or not immune boosting is present. Without immune boosting, vaccination is expected to be cost-effective or even cost-saving. With immune boosting, vaccination at 95% coverage is not expected to be cost-effective, and may even cause net health losses. Conclusions Cost-effectiveness of varicella vaccination depends strongly on the impact on HZ and the economic time horizon. Our findings reveal ethical dilemmas as varicella vaccination may result in unequal distribution of health effects between generations. Cost-effectiveness of varicella vaccination depends strongly on the impact on herpes zoster and the economic time horizon. Varicella vaccination may result in profound trans-generational differences in distribution of health benefits and losses. Ethical dilemmas could arise, as unvaccinated groups may be exposed to a substantially increased health hazard.
We study the impact of universal childhood varicella vaccination by dynamic transmission modelling and cost-effectiveness analyses. Scenarios that are considered differ by whether or not immune boosting is included, and whether or not reactivation of vaccine virus is possible. Health effects of varicella vaccination in scenarios with immune boosting are unevenly distributed: cohorts born just before introduction of vaccination and persons who refuse vaccination may pay the price for health gains in vaccinated cohorts by an increased lifetime risk of herpes zoster. These results uncover an ethical dilemma, as varicella vaccination could result in significant trans-generational inequalities of health effects.
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Affiliation(s)
- Alies van Lier
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands
| | - Anna Lugnér
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands
| | - Wim Opstelten
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, PO Box 85500, 3508 GA Utrecht, The Netherlands
| | - Petra Jochemsen
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands
| | - Jacco Wallinga
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands
| | - François Schellevis
- NIVEL, Netherlands Institute for Health Services Research, PO Box 1568, 3500 BN Utrecht, The Netherlands ; Department of General Practice & Elderly Care Medicine/EMGO Institute for Health and Care Research, VU University Medical Center, v/d Boechorststraat 7, 1081 BT Amsterdam, The Netherlands
| | - Elisabeth Sanders
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands ; Department of Paediatric Immunology and Infectious Diseases, Wilhelmina's Children Hospital, University Medical Center Utrecht, PO Box 85090, 3508 AB Utrecht, The Netherlands
| | - Hester de Melker
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment (RIVM), PO Box 1, 3720 BA Bilthoven, The Netherlands
| | - Michiel van Boven
- 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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Damm O, Ultsch B, Horn J, Mikolajczyk RT, Greiner W, Wichmann O. Systematic review of models assessing the economic value of routine varicella and herpes zoster vaccination in high-income countries. BMC Public Health 2015; 15:533. [PMID: 26041469 PMCID: PMC4455277 DOI: 10.1186/s12889-015-1861-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Accepted: 05/21/2015] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND A systematic review was conducted to assess the cost-effectiveness of routine varicella and herpes zoster (HZ) vaccination in high-income countries estimated by modelling studies. METHODS A PubMed search was performed to identify relevant studies published before October 2013. Studies were included in the review if they (i) evaluated the cost-effectiveness of routine childhood or adolescent varicella vaccination and/or HZ vaccination targeting the elderly, and if they (ii) reported results for high-income countries. RESULTS A total of 38 model-based studies were identified that fulfilled the inclusion criteria. Routine childhood or adolescent varicella vaccination was cost-effective or cost-saving from a payer perspective and always cost-saving from a societal perspective when ignoring its potential impact on HZ incidence due to reduced or absent exogenous boosting. The inclusion of the potential impact of childhood varicella vaccination on HZ led to net quality-adjusted life-year (QALY) losses or incremental cost-effectiveness ratios exceeding commonly accepted thresholds. Additional HZ vaccination could partially mitigate this effect. Studies focusing only on the evaluation of HZ vaccination reported a wide range of results depending on the selected target age-group and the vaccine price, but most found HZ vaccination to be a cost-effective or marginally cost-effective intervention. Cost-effectiveness of HZ vaccination was strongly dependent on the age at vaccination, the price of the vaccine, the assumed duration of protection and the applied cost per QALY threshold. CONCLUSIONS While HZ vaccination is mostly considered cost-effective, cost-effectiveness of varicella vaccination primarily depends on the in- or exclusion of exogenous boosting in the model. As a consequence, clarification on the role of exogenous boosting is crucial for decision-making regarding varicella vaccination.
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Affiliation(s)
- Oliver Damm
- Department of Health Economics and Health Care Management, Bielefeld School of Public Health, Bielefeld University, Bielefeld, Germany.
| | | | - Johannes Horn
- Helmholtz Centre for Infection Research, Brunswick, Germany.
| | - Rafael T Mikolajczyk
- Helmholtz Centre for Infection Research, Brunswick, Germany.
- Hannover Medical School, Hannover, Germany.
| | - Wolfgang Greiner
- Department of Health Economics and Health Care Management, Bielefeld School of Public Health, Bielefeld University, Bielefeld, Germany.
| | - Ole Wichmann
- Immunisation Unit, Robert Koch Institute, Berlin, Germany.
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The vaccine against varicella: do we have the optimal vaccine? Pediatr Infect Dis J 2014; 33:1083-4. [PMID: 25093978 DOI: 10.1097/inf.0000000000000488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Papaloukas O, Giannouli G, Papaevangelou V. Successes and challenges in varicella vaccine. THERAPEUTIC ADVANCES IN VACCINES 2014; 2:39-55. [PMID: 24757524 DOI: 10.1177/2051013613515621] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Varicella is a highly contagious disease caused by primary infection with varicella zoster virus (VZV). VZV infection, as well as varicella vaccination, induces VZV-specific antibody and T-cell-mediated immunity, essential for recovery. The immune responses developed contribute to protection following re-exposure to VZV. When cell-mediated immunity declines, as occurs with aging or immunosuppression, reactivation of VZV leads to herpes zoster (HZ). It has been almost 20 years since universal varicella vaccination has been implemented in many areas around the globe and this has resulted in a significant reduction of varicella-associated disease burden. Successes are reviewed here, whilst emphasis is put on the challenges ahead. Most countries that have not implemented routine childhood varicella vaccination have chosen to vaccinate high-risk groups alone. The main reasons for not introducing universal vaccination are discussed, including fear of age shift of peak incidence age and of HZ incidence increase. Possible reasons for not observing the predicted increase in HZ incidence are explored. The advantages and disadvantages of universal vs targeted vaccination as well as different vaccination schedules are discussed.
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Affiliation(s)
- Orestis Papaloukas
- Second Department of Pediatrics, University of Athens Medical School, P&A Kyriakou Childrens' Hospital, Greece
| | - Georgia Giannouli
- Second Department of Pediatrics, University of Athens Medical School, P&A Kyriakou Childrens' Hospital, Greece
| | - Vassiliki Papaevangelou
- Third Department of Pediatrics, University of Athens Medical School, General University Hospital 'ATTIKON', Rimini 1, Chaidari 124 62, Greece
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Macartney K, Heywood A, McIntyre P. Vaccines for post-exposure prophylaxis against varicella (chickenpox) in children and adults. Cochrane Database Syst Rev 2014; 2014:CD001833. [PMID: 24954057 PMCID: PMC7061782 DOI: 10.1002/14651858.cd001833.pub3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
BACKGROUND The prevention of varicella (chickenpox) using live attenuated varicella vaccines has been demonstrated both in randomised controlled trials (RCTs) and in population-based immunisation programmes in countries such as the United States and Australia. Many countries do not routinely immunise children against varicella and exposures continue to occur. Although the disease is often mild, complications such as secondary bacterial infection, pneumonitis and encephalitis occur in about 1% of cases, usually leading to hospitalisation. The use of varicella vaccine in persons who have recently been exposed to the varicella zoster virus has been studied as a form of post-exposure prophylaxis (PEP). OBJECTIVES To assess the efficacy and safety of vaccines for use as PEP for the prevention of varicella in children and adults. SEARCH METHODS We searched CENTRAL (2014, Issue 1), MEDLINE (1966 to March week 1, 2014), EMBASE (January 1990 to March 2014) and LILACS (1982 to March 2014). We searched for unpublished trials registered on the clinicaltrials.gov and WHO ICTRP websites. SELECTION CRITERIA RCTs and quasi-RCTs of varicella vaccine for PEP compared with placebo or no intervention. The outcome measures were efficacy in prevention of clinical cases and/or laboratory-confirmed clinical cases and adverse events following vaccination. DATA COLLECTION AND ANALYSIS Two review authors independently extracted and analysed data using Review Manager software. MAIN RESULTS We identified three trials involving 110 healthy children who were siblings of household contacts. The included trials varied in study quality, vaccine used, length of follow-up and outcomes measured and, as such, were not suitable for meta-analysis. We identified high or unclear risk of bias in two of the three included studies. Overall, 13 out of 56 vaccine recipients (23%) developed varicella compared with 42 out of 54 placebo (or no vaccine) recipients (78%). Of the vaccine recipients who developed varicella, the majority only had mild disease (with fewer than 50 skin lesions). In the three trials, most participants received PEP within three days following exposure; too few participants were vaccinated four to five days post-exposure to ascertain the efficacy of vaccine given more than three days after exposure. No included trial reported on adverse events following immunisation. AUTHORS' CONCLUSIONS These small trials suggest varicella vaccine administered within three days to children following household contact with a varicella case reduces infection rates and severity of cases. We identified no RCTs for adolescents or adults. Safety was not adequately addressed.
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Affiliation(s)
- Kristine Macartney
- Children's Hospital at Westmead and University of SydneyNational Centre for Immunisation Research and Surveillance of Vaccine Preventable DiseasesLocked Bag 4001WestmeadSydneyNSWAustralia2145
| | - Anita Heywood
- University of New South WalesSchool of Public Health and Community MedicineLevel 2, Samuels BuildingGate 11, Botany StreetKensingtonNSWAustralia2052
| | - Peter McIntyre
- Children's Hospital at Westmead and University of SydneyNational Centre for Immunisation Research and Surveillance of Vaccine Preventable DiseasesLocked Bag 4001WestmeadSydneyNSWAustralia2145
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Willem L, Stijven S, Vladislavleva E, Broeckhove J, Beutels P, Hens N. Active learning to understand infectious disease models and improve policy making. PLoS Comput Biol 2014; 10:e1003563. [PMID: 24743387 PMCID: PMC3990517 DOI: 10.1371/journal.pcbi.1003563] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 02/12/2014] [Indexed: 12/17/2022] Open
Abstract
Modeling plays a major role in policy making, especially for infectious disease interventions but such models can be complex and computationally intensive. A more systematic exploration is needed to gain a thorough systems understanding. We present an active learning approach based on machine learning techniques as iterative surrogate modeling and model-guided experimentation to systematically analyze both common and edge manifestations of complex model runs. Symbolic regression is used for nonlinear response surface modeling with automatic feature selection. First, we illustrate our approach using an individual-based model for influenza vaccination. After optimizing the parameter space, we observe an inverse relationship between vaccination coverage and cumulative attack rate reinforced by herd immunity. Second, we demonstrate the use of surrogate modeling techniques on input-response data from a deterministic dynamic model, which was designed to explore the cost-effectiveness of varicella-zoster virus vaccination. We use symbolic regression to handle high dimensionality and correlated inputs and to identify the most influential variables. Provided insight is used to focus research, reduce dimensionality and decrease decision uncertainty. We conclude that active learning is needed to fully understand complex systems behavior. Surrogate models can be readily explored at no computational expense, and can also be used as emulator to improve rapid policy making in various settings.
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Affiliation(s)
- Lander Willem
- Centre for Health Economics Research & Modeling of Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
- Department of Mathematics and Computer Science, University of Antwerp, Antwerp, Belgium
- Interuniversitary Institute for Biostatistics and statistical Bioinformatics, Hasselt University, Diepenbeek, Belgium
- * E-mail:
| | - Sean Stijven
- Department of Mathematics and Computer Science, University of Antwerp, Antwerp, Belgium
- Department of Information Technology, Gent University–iMinds, Gent, Belgium
| | | | - Jan Broeckhove
- Department of Mathematics and Computer Science, University of Antwerp, Antwerp, Belgium
| | - Philippe Beutels
- Centre for Health Economics Research & Modeling of Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
- School of Public Health and Community Medicine, The University of New South Wales, Sydney, Australia
| | - Niel Hens
- Centre for Health Economics Research & Modeling of Infectious Diseases, Vaccine and Infectious Disease Institute, University of Antwerp, Antwerp, Belgium
- Interuniversitary Institute for Biostatistics and statistical Bioinformatics, Hasselt University, Diepenbeek, Belgium
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Rozenbaum MH, De Cao E, Westra TA, Postma MJ. Dynamic models for health economic assessments of pertussis vaccines: what goes around comes around…. Expert Rev Vaccines 2014; 11:1415-28. [DOI: 10.1586/erv.12.130] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Goldman GS, King PG. Vaccination to prevent varicella: Goldman and King's response to Myers' interpretation of Varicella Active Surveillance Project data. Hum Exp Toxicol 2013; 33:886-93. [PMID: 24275643 PMCID: PMC4363126 DOI: 10.1177/0960327113512340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND There is increasing evidence that herpes zoster (HZ) incidence rates among children and adults (aged <60 years) with a history of natural varicella are influenced primarily by the frequency of exogenous exposures, while asymptomatic endogenous reactivations help to cap the rate at approximately 550 cases/100,000 person-years when exogenous boosting becomes rare. The Antelope Valley Varicella Active Surveillance Project was funded by the Centers for Disease Control and Prevention in 1995 to monitor the effects of varicella vaccination in one of the three representative regions of the United States. The stability in the data collection and number of reporting sites under varicella surveillance from 1995-2002 and HZ surveillance during 2000-2001 and 2006-2007 contributed to the robustness of the discerned trends. DISCUSSION Varicella vaccination may be useful for leukemic children; however, the target population in the United States is all children. Since the varicella vaccine inoculates its recipients with live, attenuated varicella-zoster virus (VZV), clinical varicella cases have dramatically declined. Declining exogenous exposures (boosts) from children shedding natural VZV have caused waning cell-mediated immunity. Thus, the protection provided by varicella vaccination is neither lifelong nor complete. Moreover, dramatic increases in the incidence of adult shingles cases have been observed since HZ was added to the surveillance in 2000. In 2013, this topic is still debated and remains controversial in the United States. SUMMARY When the costs of the booster dose for varicella and the increased shingles recurrences are included, the universal varicella vaccination program is neither effective nor cost-effective.
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Affiliation(s)
- G S Goldman
- Independent Computer Scientist, Pearblossom, CA, USA
| | - P G King
- Facility Automation Management Engineering (FAME) Systems, Lake Hiawatha, NJ, USA
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Paul SP, Abdelrhim H, Kane M, Haque SY. Varicella and secondary pneumonia in a healthy child: is it time to introduce varicella vaccine in the UK? Br J Hosp Med (Lond) 2013; 74:590-1. [PMID: 24105315 DOI: 10.12968/hmed.2013.74.10.590] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A previously healthy 8-month-old boy presented to the emergency department with a 1-week history of chickenpox infection. His routine immunizations were up-to-date. His parents reported a high temperature (up to 39.5°C) in the preceding 48 hours and that he also had a mild cough, episodes of vomiting and loose stools. He had fed poorly in the 24 hours before presentation. Clinical assessment revealed a temperature of 36.7°C, heart rate 130/min, respiratory rate of 34/min and crusted chickenpox lesions. The infant was alert, smiling and playful, and systemic examination was otherwise unremarkable. He was admitted for monitoring of his fluid intake and temperature. As the infant continued to vomit intermittently in the 6 hours post admission, blood investigations were done and intravenous fluids were commenced. Laboratory investigations did not reveal biochemical evidence of dehydration, but they did show raised inflammatory markers: white blood cell count 24.8 × 109/litre, neutrophil count 19.8 × 109/litre and C-reactive protein 227mg/litre. In view of these results and the ongoing high fever, a chest X-ray was performed, revealing right upper lobe consolidation and collapse (Figure 1). Oral amoxicillin and flucloxacillin were started and oral feeding was successfully reestablished over the next 24 hours. He was discharged home after 48 hours, to complete a full 7-day course of oral antibiotics.
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Affiliation(s)
- Siba P Paul
- Specialty Trainee Year 5 in Paediatrics in the Department of Paediatrics, Yeovil District Hospital NHS Foundation Trust, Yeovil, Somerset
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Varicella zoster virus in American Samoa: seroprevalence and predictive value of varicella disease history in elementary and college students. Epidemiol Infect 2013; 142:1002-7. [PMID: 23890292 DOI: 10.1017/s095026881300174x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The epidemiology of varicella is believed to differ between temperate and tropical countries. We conducted a varicella seroprevalence study in elementary and college students in the US territory of American Samoa before introduction of a routine varicella vaccination programme. Sera from 515 elementary and 208 college students were tested for the presence of varicella-zoster virus (VZV) IgG antibodies. VZV seroprevalence increased with age from 76·0% in the 4-6 years group to 97·7% in those aged ⩾23 years. Reported history of varicella disease for elementary students was significantly associated with VZV seropositivity. The positive and negative predictive values of varicella disease history were 93·4% and 36·4%, respectively, in elementary students and 97·6% and 3·0%, respectively, in college students. VZV seroprevalence in this Pacific island appears to be similar to that in temperate countries and suggests endemic VZV circulation.
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Validity of a reported history of chickenpox in targeting varicella vaccination at susceptible adolescents in England. Vaccine 2013; 32:1213-7. [PMID: 23871823 PMCID: PMC3969712 DOI: 10.1016/j.vaccine.2013.06.098] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2013] [Revised: 05/20/2013] [Accepted: 06/25/2013] [Indexed: 12/15/2022]
Abstract
INTRODUCTION In the UK, primary varicella is usually a mild infection in children, but can cause serious illness in susceptible pregnant women and adults. The UK Joint Committee on Vaccination and Immunisation is considering an adolescent varicella vaccination programme. Cost-effectiveness depends upon identifying susceptibles and minimising vaccine wastage, and chickenpox history is one method to screen for eligibility. To inform this approach, we estimated the proportion of adolescents with varicella antibodies by reported chickenpox history. METHODS Recruitment occurred through secondary schools in England from February to September 2012. Parents were asked about their child's history of chickenpox, explicitly setting the context in terms of the implications for vaccination. 247 adolescents, whose parents reported positive (120), negative (77) or uncertain (50) chickenpox history provided oral fluid for varicella zoster virus-specific immunoglobulin-G (VZV-IgG) testing. RESULTS 109 (90.8% [85.6-96.0%]) adolescents with a positive chickenpox history, 52 (67.5% [57.0-78.1%]) with a negative history and 42 (84.0% [73.7-94.3%]) with an uncertain history had VZV-IgG suggesting prior infection. Combining negative and uncertain histories, 74% had VZV-IgG (best-case). When discounting low total-IgG samples and counting equivocals as positive (worst-case), 84% had VZV-IgG. We also modelled outcomes by varying the negative predictive value (NPV) for the antibody assay, and found 74-87% under the best-case and 84-92% under the worst-case scenario would receive vaccine unnecessarily as NPV falls to 50%. CONCLUSION Reported chickenpox history discriminates between varicella immunity and susceptibility in adolescents, but significant vaccine wastage would occur if this approach alone were used to determine vaccine eligibility. A small but important proportion of those with positive chickenpox history would remain susceptible. These data are needed to determine whether reported history, with or without oral fluid testing in those with negative and uncertain history, is sufficiently discriminatory to underpin a cost-effective adolescent varicella vaccination programme.
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Goldman GS, King PG. Review of the United States universal varicella vaccination program: Herpes zoster incidence rates, cost-effectiveness, and vaccine efficacy based primarily on the Antelope Valley Varicella Active Surveillance Project data. Vaccine 2013; 31:1680-94. [PMID: 22659447 PMCID: PMC3759842 DOI: 10.1016/j.vaccine.2012.05.050] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Revised: 05/10/2012] [Accepted: 05/19/2012] [Indexed: 12/31/2022]
Abstract
In a cooperative agreement starting January 1995, prior to the FDA's licensure of the varicella vaccine on March 17, the Centers for Disease Control and Prevention (CDC) funded the Los Angeles Department of Health Services' Antelope Valley Varicella Active Surveillance Project (AV-VASP). Since only varicella case reports were gathered, baseline incidence data for herpes zoster (HZ) or shingles was lacking. Varicella case reports decreased 72%, from 2834 in 1995 to 836 in 2000 at which time approximately 50% of children under 10 years of age had been vaccinated. Starting in 2000, HZ surveillance was added to the project. By 2002, notable increases in HZ incidence rates were reported among both children and adults with a prior history of natural varicella. However, CDC authorities still claimed that no increase in HZ had occurred in any US surveillance site. The basic assumptions inherent to the varicella cost-benefit analysis ignored the significance of exogenous boosting caused by those shedding wild-type VZV. Also ignored was the morbidity associated with even rare serious events following varicella vaccination as well as the morbidity from increasing cases of HZ among adults. Vaccine efficacy declined below 80% in 2001. By 2006, because 20% of vaccinees were experiencing breakthrough varicella and vaccine-induced protection was waning, the CDC recommended a booster dose for children and, in 2007, a shingles vaccination was approved for adults aged 60 years and older. In the prelicensure era, 95% of adults experienced natural chickenpox (usually as children)-these cases were usually benign and resulted in long-term immunity. Varicella vaccination is less effective than the natural immunity that existed in prevaccine communities. Universal varicella vaccination has not proven to be cost-effective as increased HZ morbidity has disproportionately offset cost savings associated with reductions in varicella disease. Universal varicella vaccination has failed to provide long-term protection from VZV disease.
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Affiliation(s)
- G S Goldman
- Independent Computer Scientist, P.O. Box 847, Pearblossom, CA 93553, United States.
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Bilcke J, van Hoek AJ, Beutels P. Childhood varicella-zoster virus vaccination in Belgium: cost-effective only in the long run or without exogenous boosting? Hum Vaccin Immunother 2013; 9:812-22. [PMID: 23321955 DOI: 10.4161/hv.23334] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
AIM To assess the effectiveness and cost-effectiveness of a universal childhood varicella-zoster vaccination programme in Belgium (1) using the most recent Belgian data on varicella-zoster burden, (2) exploring different options for the timing of the second dose, (3) obtaining results with and without exogenous natural boosting, and (4) investigating the possible additional benefit of zoster booster vaccination for adults at age 50 or 60 y. METHODS An extensively studied and improved dynamic model is used to estimate primary and breakthrough chickenpox and zoster cases over time. For a range of vaccination options, we compared the direct costs (health care payer perspective) and health outcomes (including Quality-Adjusted Life-Years (QALYs) lost) associated with chickenpox and herpes zoster. Estimates of social contact patterns, health care use, costs and QALY losses are almost exclusively based on Belgian databases and surveys. RESULTS AND CONCLUSIONS If exogenous natural boosting exists, a net loss in QALYs is expected for several decades after implementing a universal chickenpox vaccination programme, due to an increase in zoster mainly in persons aged 50-80 y. This result holds also for scenarios that minimise or counteract the expected increase in zoster incidence (e.g. additional booster vaccinations in adults). However, if the boosting hypothesis is not true or if costs and QALYs are cumulated over at least 33 to more than 100 y after vaccination (depending on the assumptions made), different options for universal 2-dose vaccination against chickenpox in Belgium would be cost-effective at a vaccine price of €43/dose or lower.
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Affiliation(s)
- Joke Bilcke
- Center for Health Economic Research and Modeling Infectious Diseases (CHERMID); Vaccine and Infectious Disease Institute (Vaxinfectio); University of Antwerp; Wilrijk, Belgium
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Khaleel HA, Abdelhussein HM. Clinical epidemiology of chickenpox in Iraq from 2007-2011. Glob J Health Sci 2012; 5:180-6. [PMID: 23283051 PMCID: PMC4776987 DOI: 10.5539/gjhs.v5n1p180] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 10/25/2012] [Indexed: 11/13/2022] Open
Abstract
Varicella zoster (chickenpox) infection is an acute common disease caused by the varicella zoster virus (VZV). Children are most susceptible to infection. In non-vaccinated populations, primary infection tends to occur at a younger age. In 1998, the World Health Organization (WHO) recommended that routine childhood varicella vaccination be considered in countries where the disease is a relatively important public health and socioeconomic problem, and where high (85 to 90%) and sustained vaccine coverage can be achieved.
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Pierik JGJ, Gumbs PD, Fortanier SAC, Van Steenwijk PCE, Postma MJ. Epidemiological characteristics and societal burden of varicella zoster virus in the Netherlands. BMC Infect Dis 2012; 12:110. [PMID: 22574722 PMCID: PMC3464966 DOI: 10.1186/1471-2334-12-110] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2011] [Accepted: 05/10/2012] [Indexed: 11/17/2022] Open
Abstract
Background Varicella and herpes zoster are both caused by varicella zoster virus (VZV) infection or reactivation and may lead to complications associated with a (severe) societal burden. Because the epidemiology of VZV-related diseases in the Netherlands remains largely unknown or incomplete, the main objective of this study was to study the primary care incidence, associated complications and health care resource use. Methods We investigated the incidence of VZV complications in the Dutch general practitioner (GP) practices and pharmacies in a retrospective population-based cohort study (2004–2008) based on longitudinal GP data including free text fields, hospital referral and discharge letters from approximately 165,000 patients. Results The average annual incidence of varicella GP-consultations was 51.5 per 10,000 (95% CI 44.4-58.7) overall; 465.5 per 10,000 for 0–1 year-olds; 610.8 per 10,000 for 1–4 year-olds; 153.5 per 10,000 for 5–9 year-olds; 8,3 per 10,000 for >10 year olds. When only ICPC coded diagnoses were analyzed the incidence was 27% lower. The proportion of complications among varicella patients was 34.9%. Most frequently complications were upper respiratory tract infections. Almost half of the varicella patients received medication. The referral rate based on GP consultations was 1.7%. The average annual incidence of herpes zoster GP-consultations was 47.5 per 10,000 (95% CI 40.6-54.4). The incidence increased with age; 32.8 per 10,000 for <60 year-olds; 93.1 per 10,000 for 60–64 year-olds and 113.2 per 10,000 for >65 year olds. When estimating herpes zoster incidence only on ICPC coded information, the incidence was 28% lower. The complication rate of herpes zoster was 32.9%. Post herpetic neuralgia was seen most often. Of patients diagnosed with herpes zoster 67.8% received medication. The referral rate based on GP consultations was 3.5%. Conclusions For varicella the highest incidence of GP-consultations was found in 1–4 year-olds, for herpes zoster in the >65 years olds. The occurrence of complications was not age-dependent but varies per complication. When estimating incidence of VZV-related diseases in primary care, based on diagnostic codes only, one should be aware of a gross underestimation of the incidence. Our analysis may have important implications for the outcomes of upcoming cost-effectiveness analyses on VZV vaccination.
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Affiliation(s)
- Jorien G J Pierik
- Department of Pharmacy, Unit of PharmacoEpidemiology & PharmacoEconomics, University of Groningen, Antonius Deusinglaan 1, Groningen, 9713 AV, The Netherlands.
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Knuf M, Zepp F, Helm K, Maurer H, Prieler A, Kieninger-Baum D, Douha M, Willems P. Antibody persistence for 3 years following two doses of tetravalent measles-mumps-rubella-varicella vaccine in healthy children. Eur J Pediatr 2012; 171:463-70. [PMID: 21935584 DOI: 10.1007/s00431-011-1569-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 09/05/2011] [Indexed: 11/28/2022]
Abstract
UNLABELLED Two doses of a varicella-containing vaccine in healthy children <12 years are suggested to induce better protection than a single dose. Persistence of immunity against measles, mumps, rubella, and varicella as well as varicella breakthrough cases were assessed 3 years after two-dose measles, mumps, rubella, and varicella (MMRV) vaccination or concomitant MMR (Priorix™) and varicella (Varilrix™) vaccination. Four hundred ninety-four healthy children, 12-18 months old at the time of the first dose, received either two doses of MMRV vaccine (GlaxoSmithKline Biologicals) 42-56 days apart (MMRV, N = 371) or one dose of MMR and varicella vaccines administered simultaneously at separate sites, followed by another MMR vaccination 42-56 days later (MMR + V, N = 123). Three hundred-four subjects participated in 3-year follow-up for persistence of immunity and occurrence of breakthrough varicella (MMRV, N = 225; MMR + V, N = 79). Antibodies were measured by ELISA (measles, mumps, rubella) and immunofluorescence (varicella). Contacts with individuals with varicella or zoster and cases of breakthrough varicella disease were recorded. Three years post-vaccination seropositivity rates in subjects seronegative before vaccination were: MMRV-measles, 98.5% (geometric mean titer [GMT] = 3,599.6); mumps, 97.4% (GMT = 1,754.5); rubella, 100% (GMT = 51.9); varicella, 99.4% (GMT = 225.5); MMR + V-measles, 97.0% (GMT = 1,818.8); mumps, 93.8% (GMT = 1,454.6); rubella, 100% (GMT = 53.8); and varicella, 96.8% (GMT = 105.8). Of the subjects, 15-20% reported contact with individuals with varicella/zoster each year. After 3 years, the cumulative varicella breakthrough disease rate was 0.7% (two cases) in the MMRV group and 5.4% (five cases) in the MMR + V group. CONCLUSION Immunogenicity of the combined MMRV vaccine was sustained 3 years post-vaccination. (208136/041/NCT00406211).
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Affiliation(s)
- Markus Knuf
- Children's Department of Pediatrics, University Medicine Hospital, Johannes Gutenberg-University, Langenbeckstrasse 1, 55101 Mainz, Germany.
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Abstract
Vaccine development has played a hugely important role in combating infectious disease. Despite this success, there is still a great need for new vaccines and these are emerging far more slowly than we would wish. Despite the massive expansion in understanding of immune responses to infection, research is often hindered by a lack of understanding of the immune responses required specifically for protection, or by a lack of approved adjuvants and delivery systems to induce the required responses. In addition, the financial commitment required to license new vaccines is significant, and the more lucrative markets are often not those with the greatest need. In this review, we discuss many of the hurdles that new vaccines must overcome in order to reduce morbidity and mortality, and some of the initiatives that are being attempted to supply new vaccines to those that need them most.
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Affiliation(s)
- Petra Oyston
- Biomedical Sciences, Dstl Porton Down, Salisbury SP4 0JQ, UK
| | - Karen Robinson
- Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
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Abstract
Nearly all human beings, by the time they reach adolescence, are infected with multiple herpesviruses. At any given time, this family of viruses accounts for 35-40 billion human infections worldwide, making herpesviruses among the most prevalent pathogens known to exist. Compared to most other viruses, herpesviruses are also unique in that infection lasts the life of the host. Remarkably, despite their prevalence and persistence, little is known about how these viruses interact with their hosts, especially during the clinically asymptomatic phase of infection referred to as latency. This review explores data in human and animal systems that reveal the ability of latent herpesviruses to modulate the immune response to self and environmental antigens. From the perspective of the host, there are both potentially detrimental and surprisingly beneficial effects of this lifelong interaction. The realization that latent herpesvirus infection modulates immune responses in asymptomatic hosts forces us to reconsider what constitutes a 'normal' immune system in a healthy individual.
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Affiliation(s)
- Douglas W. White
- Division of Rheumatology, Gundersen Lutheran Medical Center, La Crosse, WI, USA
| | - R. Suzanne Beard
- Department of Biological Sciences, Purdue University, West Lafayette, IN, USA
- Department of Microbiology & Immunology, Wake Forest University School of Medicine, Winston-Salem NC, USA
| | - Erik S. Barton
- Department of Microbiology & Immunology, Wake Forest University School of Medicine, Winston-Salem NC, USA
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van Hoek AJ, Melegaro A, Gay N, Bilcke J, Edmunds WJ. The cost-effectiveness of varicella and combined varicella and herpes zoster vaccination programmes in the United Kingdom. Vaccine 2011; 30:1225-34. [PMID: 22119592 DOI: 10.1016/j.vaccine.2011.11.026] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Revised: 11/04/2011] [Accepted: 11/07/2011] [Indexed: 10/15/2022]
Abstract
BACKGROUND Despite the existence of varicella vaccine, many developed countries have not introduced it into their national schedules, partly because of concerns about whether herpes zoster (HZ, shingles) will increase due to a lack of exogenous boosting. The magnitude of any increase in zoster that might occur is dependent on rates at which adults and children mix - something that has only recently been quantified - and could be reduced by simultaneously vaccinating older individuals against shingles. This study is the first to assess the cost-effectiveness of combined varicella and zoster vaccination options and compare this to alternative programmes. METHODS AND FINDINGS The cost-effectiveness of various options for the use of varicella-zoster virus (VZV) containing vaccines was explored using a transmission dynamic model. Underlying contact rates are estimated from a contemporary survey of social mixing patterns, and uncertainty in these derived from bootstrapping the original sample. The model was calibrated to UK data on varicella and zoster incidence. Other parameters were taken from the literature. UK guidance on perspective and discount rates were followed. The results of the incremental cost-effectiveness analysis suggest that a combined policy is cost-effective. However, the cost-effectiveness of this policy (and indeed the childhood two-dose policy) is influenced by projected benefits that accrue many decades (80-100 years or more) after the start of vaccination. If the programme is evaluated over shorter time frames, then it would be unlikely to be deemed cost-effective, and may result in declines in population health, due to a projected rise in the incidence of HZ. The findings are also sensitive to a number of parameters that are inaccurately quantified, such as the risk of HZ in varicella vaccine responders. CONCLUSIONS Policy makers should be aware of the potential negative benefits in the first 30-50 years after introduction of a childhood varicella vaccine. This can only be partly mitigated by the introduction of a herpes zoster vaccine. They have to decide how they value the potential benefits beyond this time to consider childhood vaccination cost effective.
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Affiliation(s)
- Albert Jan van Hoek
- Immunisation, Hepatitis and Blood Safety Department, Health Protection Agency, LondonNW9 5EQ, UK.
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Wolleswinkel-van den Bosch JH, Speets AM, Rümke HC, Gumbs PD, Fortanier SC. The burden of varicella from a parent's perspective and its societal impact in The Netherlands: an Internet survey. BMC Infect Dis 2011; 11:320. [PMID: 22093160 PMCID: PMC3241223 DOI: 10.1186/1471-2334-11-320] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2011] [Accepted: 11/17/2011] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Varicella is a common childhood disease. Only 5% of first varicella-zoster-virus infections occur asymptomatically. Most data on the burden of varicella stem from health service databases. This study aims to provide insight in the burden of varicella from a parent's perspective including cases outside the healthcare system. METHODS An internet questionnaire was developed for parents in the Netherlands to report health care resource use and productivity losses during the varicella episode in their child younger than 6 years. 11,367 invitations were sent out to members with children of an internet panel of a market research agency. 4,168 (37%) parents started the questionnaire (response rate), of which 360 (9%) stopped before completion and 1,838 (44%) were out of the target group. In total 1,970 parents completed the questionnaire. The questionnaire provided a symptom list ranging from common symptoms, such as skin vesicles, itching to fits or convulsions. A posteriori, in the analyses, the symptoms 'skin infections', 'fits/convulsions', 'unconsciousness', and 'balance and movement disorders' were labelled as complications. There was no restriction to time since the varicella episode for inclusion in the analyses. RESULTS The 1,970 respondents had in total 2,899 children aged younger than six years, of which 2,564 (88%) children had had varicella. In 62% of the episodes the parent did not seek medical help. In 18% of all episodes symptoms labelled as complications were reported; in 11% of all episodes parents visited a medical doctor (MD) for a complication. Reporting of complications did not differ (X2 ; p = 0.964) between children with a recent (≤ 12 months ago) or a more distant (> 12 months) history of varicella. Prescription drugs were used in 12% of the children with varicella; OTC drugs in 72%. Parents reported work loss in 17% of the varicella-episodes (23% when MD visit; 14% when no MD-visit) for on average 14 hours, which equals to 2.5 hours of work loss for any given varicella-episode. CONCLUSIONS This study shows the full spectrum of varicella-episodes and associated healthcare use, including the large proportion of cases not seeking medical care and the societal impact associated with those cases.
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Rozenbaum MH, Mangen MJJ, Giaquinto C, Wilschut JC, Hak E, Postma MJ. Cost-effectiveness of rotavirus vaccination in the Netherlands; the results of a consensus model. BMC Public Health 2011; 11:462. [PMID: 21663620 PMCID: PMC3129591 DOI: 10.1186/1471-2458-11-462] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Accepted: 06/10/2011] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND Each year rotavirus gastroenteritis results in thousands of paediatric hospitalisations and primary care visits in the Netherlands. While two vaccines against rotavirus are registered, routine immunisation of infants has not yet been implemented. Existing cost-effectiveness studies showed inconsistent results for these vaccines because of lack of consensus on the impact. We aimed to investigate which factors had a major impact on cost-effectiveness and were primarily responsible for the large differences in previously estimated cost-effectiveness ratios. METHODS Based on updated data on health outcomes and cost estimates, we re-assessed the cost-effectiveness of routine paediatric rotavirus vaccination within the National Immunization Program for the Netherlands. Two consensus meetings were organised with national and international experts in the field to achieve consensus and resolve potential controversies. RESULTS It was estimated that rotavirus vaccination in the Netherlands could avert 34,214 cases of rotavirus gastroenteritis in children aged less than 5 years. Notably, 2,779 hospitalisations were averted of which 315 were extensions of existing hospital stays due to nosocomial rotavirus infection. With a threshold varying from 20K € - 50K € per QALY and according to the base-case scenario, the full vaccination costs per child leading to cost-effectiveness was € 57.76 -€ 77.71. Results were sensitive to the inclusion of potential vaccine induced herd protection, QALY losses and number of deaths associated with rotavirus gastroenteritis. CONCLUSIONS Our economic analysis indicates that inclusion of rotavirus vaccination in the Dutch National Immunization Program might be cost-effective depending on the cost of the vaccine and the impact of rotavirus gastroenteritis on children's quality of life.
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Affiliation(s)
- Mark H Rozenbaum
- Unit of PharmacoEpidemiology & PharmacoEconomics (PE2), Department of Pharmacy, University of Groningen, Groningen, The Netherlands
- CoRoVa = Consensus on Rotavirus Vaccination
| | - Marie-Josee J Mangen
- University Medical Center Utrecht, Julius Center for Health Sciences and Primary Care, Utrecht, The Netherlands
| | - Carlo Giaquinto
- Department of Paediatrics, Università degli Studi di Padova, Padova, Italy
| | - Jan C Wilschut
- Department of Medical Microbiology, Molecular Virology Section, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - Eelko Hak
- Unit of PharmacoEpidemiology & PharmacoEconomics (PE2), Department of Pharmacy, University of Groningen, Groningen, The Netherlands
| | - Maarten J Postma
- Unit of PharmacoEpidemiology & PharmacoEconomics (PE2), Department of Pharmacy, University of Groningen, Groningen, The Netherlands
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Jit M, Brisson M. Modelling the epidemiology of infectious diseases for decision analysis: a primer. PHARMACOECONOMICS 2011; 29:371-86. [PMID: 21504239 PMCID: PMC7100690 DOI: 10.2165/11539960-000000000-00000] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The number of economic evaluations related to infectious disease topics has increased over the last 2 decades. However, many such evaluations rely on models that do not take into account unique features of infectious diseases that can affect the estimated value of interventions against them. These include their transmissibility from infected to susceptible individuals, the possibility of acquiring natural immunity following recovery from infection and the uncertainties that arise as a result of their complex natural history and epidemiology. Modellers conducting economic evaluations of infectious disease interventions need to know the main features of different types of infectious disease models, the situations in which they should be applied and the effects of model choices on the cost effectiveness of interventions.
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Affiliation(s)
- Mark Jit
- Modelling and Economics Unit, Centre for Infections, Health Protection Agency, London, UK.
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Land JA, Van Bergen JEAM, Morré SA, Postma MJ. Epidemiology of Chlamydia trachomatis infection in women and the cost-effectiveness of screening. Hum Reprod Update 2009; 16:189-204. [PMID: 19828674 DOI: 10.1093/humupd/dmp035] [Citation(s) in RCA: 118] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND The majority of Chlamydia trachomatis infections in women are asymptomatic, but may give rise to pelvic inflammatory disease (PID) and tubal infertility. Screening programmes aim at reducing morbidity in individuals by early detection and treatment, and at decreasing the overall prevalence of infection in the population. A number of modelling studies have tried to calculate the threshold prevalence of chlamydia lower genital tract infection above which screening becomes cost-effective. There is considerable debate over the exact complication rates after chlamydia infections, and more precise estimates of PID and tubal infertility are needed, for instance to be inserted in economic models. METHODS With reference to key studies and systematic reviews, an overview is provided focusing on the epidemiology of chlamydia infection and the risk-estimates of its late complications. RESULTS In the literature, the generally assumed risk of developing PID after lower genital tract chlamydia infection varies considerably, and is up to 30%. For developing tubal infertility after PID the risks are 10-20%. This implies that the risk of test-positive women of developing tubal infertility would range between 0.1 and 6%. We included chlamydia IgG antibody testing in a model and estimated a risk of tubal infertility up to 4.6%. CONCLUSION The risk of developing late complications after chlamydia lower genital tract infection appears low. High quality RCTs dealing with the transition from cervicitis to infertility are needed to broaden the evidence. In screening programmes, chlamydia antibody testing, as an intermediate marker for potential adverse sequelae, might enable more precise estimates.
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Affiliation(s)
- J A Land
- Department of Obstetrics and Gynaecology, University Medical Center Groningen, Groningen, The Netherlands.
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Soárez PCD, Novaes HMD, Sartori AMC. Impact of methodology on the results of economic evaluations of varicella vaccination programs: is it important for decision-making? CAD SAUDE PUBLICA 2009; 25 Suppl 3:S401-14. [DOI: 10.1590/s0102-311x2009001500006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2009] [Accepted: 08/19/2009] [Indexed: 11/22/2022] Open
Abstract
This study aims to review the literature on economic evaluation of childhood varicella vaccination programs and to discuss how heterogeneity in methodological aspects and estimation of parameters can affect the studies' results. After applying the inclusion criteria, 27 studies published from 1980 to 2008 were analyzed in relation to methodological differences. There was great heterogeneity in the perspective adopted, evaluation of indirect costs, type of model used, modeling of the effect on herpes zoster, and estimation of vaccine price and efficacy parameters. The factor with the greatest impact on results was the inclusion of indirect costs, followed by the perspective adopted and vaccine price. The choice of a particular methodological aspect or parameter affected the studies' results and conclusions. It is essential that authors present these choices transparently so that users of economic evaluations understand the implications of such choices and the direction in which the results of the analysis were conducted.
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