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Sacco C, Manica M, Marziano V, Fabiani M, Mateo-Urdiales A, Guzzetta G, Merler S, Pezzotti P. The impact of underreported infections on vaccine effectiveness estimates derived from retrospective cohort studies. Int J Epidemiol 2024; 53:dyae077. [PMID: 38847783 PMCID: PMC11157963 DOI: 10.1093/ije/dyae077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 05/30/2024] [Indexed: 06/10/2024] Open
Abstract
BACKGROUND Surveillance data and vaccination registries are widely used to provide real-time vaccine effectiveness (VE) estimates, which can be biased due to underreported (i.e. under-ascertained and under-notified) infections. Here, we investigate how the magnitude and direction of this source of bias in retrospective cohort studies vary under different circumstances, including different levels of underreporting, heterogeneities in underreporting across vaccinated and unvaccinated, and different levels of pathogen circulation. METHODS We developed a stochastic individual-based model simulating the transmission dynamics of a respiratory virus and a large-scale vaccination campaign. Considering a baseline scenario with 22.5% yearly attack rate and 30% reporting ratio, we explored fourteen alternative scenarios, each modifying one or more baseline assumptions. Using synthetic individual-level surveillance data and vaccination registries produced by the model, we estimated the VE against documented infection taking as reference either unvaccinated or recently vaccinated individuals (within 14 days post-administration). Bias was quantified by comparing estimates to the known VE assumed in the model. RESULTS VE estimates were accurate when assuming homogeneous reporting ratios, even at low levels (10%), and moderate attack rates (<50%). A substantial downward bias in the estimation arose with homogeneous reporting and attack rates exceeding 50%. Mild heterogeneities in reporting ratios between vaccinated and unvaccinated strongly biased VE estimates, downward if cases in vaccinated were more likely to be reported and upward otherwise, particularly when taking as reference unvaccinated individuals. CONCLUSIONS In observational studies, high attack rates or differences in underreporting between vaccinated and unvaccinated may result in biased VE estimates. This study underscores the critical importance of monitoring data quality and understanding biases in observational studies, to more adequately inform public health decisions.
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Affiliation(s)
- Chiara Sacco
- ECDC Fellowship Programme, Field Epidemiology Path (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | - Mattia Manica
- Center for Health Emergencies, Fondazione Bruno Kessler, Trento, Italy
| | | | - Massimo Fabiani
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
| | | | - Giorgio Guzzetta
- Center for Health Emergencies, Fondazione Bruno Kessler, Trento, Italy
| | - Stefano Merler
- Center for Health Emergencies, Fondazione Bruno Kessler, Trento, Italy
| | - Patrizio Pezzotti
- Department of Infectious Diseases, Istituto Superiore di Sanità, Rome, Italy
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2
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Delport D, Sanderson B, Sacks-Davis R, Vaccher S, Dalton M, Martin-Hughes R, Mengistu T, Hogan D, Abeysuriya R, Scott N. A Framework for Assessing the Impact of Outbreak Response Immunization Programs. Diseases 2024; 12:73. [PMID: 38667531 PMCID: PMC11048879 DOI: 10.3390/diseases12040073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 03/29/2024] [Accepted: 04/02/2024] [Indexed: 04/28/2024] Open
Abstract
The impact of outbreak response immunization (ORI) can be estimated by comparing observed outcomes to modelled counterfactual scenarios without ORI, but the most appropriate metrics depend on stakeholder needs and data availability. This study developed a framework for using mathematical models to assess the impact of ORI for vaccine-preventable diseases. Framework development involved (1) the assessment of impact metrics based on stakeholder interviews and literature reviews determining data availability and capacity to capture as model outcomes; (2) mapping investment in ORI elements to model parameters to define scenarios; (3) developing a system for engaging stakeholders and formulating model questions, performing analyses, and interpreting results; and (4) example applications for different settings and pathogens. The metrics identified as most useful were health impacts, economic impacts, and the risk of severe outbreaks. Scenario categories included investment in the response scale, response speed, and vaccine targeting. The framework defines four phases: (1) problem framing and data sourcing (identification of stakeholder needs, metrics, and scenarios); (2) model choice; (3) model implementation; and (4) interpretation and communication. The use of the framework is demonstrated by application to two outbreaks, measles in Papua New Guinea and Ebola in the Democratic Republic of the Congo. The framework is a systematic way to engage with stakeholders and ensure that an analysis is fit for purpose, makes the best use of available data, and uses suitable modelling methodology.
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Affiliation(s)
- Dominic Delport
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Ben Sanderson
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
| | - Rachel Sacks-Davis
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
- School of Population and Global Health, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Stefanie Vaccher
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
| | - Milena Dalton
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
| | - Rowan Martin-Hughes
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
| | - Tewodaj Mengistu
- Gavi, The Vaccine Alliance, 1218 Geneva, Switzerland; (T.M.); (D.H.)
| | - Dan Hogan
- Gavi, The Vaccine Alliance, 1218 Geneva, Switzerland; (T.M.); (D.H.)
| | - Romesh Abeysuriya
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
| | - Nick Scott
- Burnet Institute, Melbourne, VIC 3004, Australia; (B.S.); (R.S.-D.); (S.V.); (M.D.); (R.M.-H.); (R.A.); (N.S.)
- Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC 3004, Australia
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3
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Durrheim DN, Murray P, Turner N. Resurgent global measles: A threat to Australia, New Zealand and Pacific Island Countries. J Paediatr Child Health 2024; 60:73-75. [PMID: 38426362 DOI: 10.1111/jpc.16530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 02/25/2024] [Indexed: 03/02/2024]
Affiliation(s)
- David N Durrheim
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
- Population Health, Hunter New England Local Health District, Newcastle, New South Wales, Australia
| | - Peter Murray
- Population Health, Hunter New England Local Health District, Newcastle, New South Wales, Australia
| | - Nikki Turner
- Deparment of General Practice and Primary Care, University of Auckland, Auckland, New Zealand
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4
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Castiñeiras ACP, Sales AC, Picone CDM, Diogo CL, Rossi ÁD, Galliez RM, Ferreira ODC, Castiñeiras TMPP, Lopes MH, Sartori AMC. The decline of measles antibody titers in previously vaccinated adults: a cross-sectional analysis. Rev Inst Med Trop Sao Paulo 2024; 66:e4. [PMID: 38198377 PMCID: PMC10768653 DOI: 10.1590/s1678-9946202466004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 11/01/2023] [Indexed: 01/12/2024] Open
Abstract
The global reemergence of measles in 2018-2019 reinforces the relevance of high-coverage immunization to maintain the disease elimination. During an outbreak in the Sao Paulo State in 2019, several measles cases were reported in individuals who were adequately vaccinated according to the current immunization schedule recommends. This study aimed to assess measles IgG antibody seropositivity and titers in previously vaccinated adults. A cross-sectional study was conducted at CRIE-HC-FMUSP (Sao Paulo, Brazil) in 2019. It included healthy adults who had received two or more Measles-Mumps-Rubella vaccines (MMR) and excluded individuals with immunocompromising conditions. Measles IgG antibodies were measured and compared by ELISA (Euroimmun®) and chemiluminescence (LIASON®). The association of seropositivity and titers with variables of interest (age, sex, profession, previous measles, number of measles-containing vaccine doses, interval between MMR doses, and time elapsed since the last MMR dose) was analyzed. A total of 162 participants were evaluated, predominantly young (median age 30 years), women (69.8%) and healthcare professionals (61.7%). The median interval between MMR doses was 13.2 years, and the median time since the last dose was 10.4 years. The seropositivity rate was 32.7% by ELISA and 75.3% by CLIA, and a strong positive correlation was found between the tests. Multivariate analyses revealed that age and time since the last dose were independently associated with positivity. Despite being a single-center evaluation, our results suggest that measles seropositivity may be lower than expected in adequately immunized adults. Seropositivity was higher among older individuals and those with a shorter time since the last MMR vaccine dose.
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Affiliation(s)
- Anna Carla Pinto Castiñeiras
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Moléstias Infecciosas e Parasitárias, São Paulo, São Paulo, Brazil
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Centro de Referência para Imunobiológicos Especiais, São Paulo, São Paulo, Brazil
- Universidade Federal do Rio de Janeiro, Núcleo de Enfrentamento e Estudos de Doenças Infecciosas e Emergentes e Reemergentes, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Amanda Caroline Sales
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Moléstias Infecciosas e Parasitárias, São Paulo, São Paulo, Brazil
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Centro de Referência para Imunobiológicos Especiais, São Paulo, São Paulo, Brazil
| | - Camila de Melo Picone
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Moléstias Infecciosas e Parasitárias, São Paulo, São Paulo, Brazil
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Centro de Referência para Imunobiológicos Especiais, São Paulo, São Paulo, Brazil
| | - Constância Lima Diogo
- Universidade Federal do Rio de Janeiro, Núcleo de Enfrentamento e Estudos de Doenças Infecciosas e Emergentes e Reemergentes, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Átila Duque Rossi
- Universidade Federal do Rio de Janeiro, Núcleo de Enfrentamento e Estudos de Doenças Infecciosas e Emergentes e Reemergentes, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Rafael Mello Galliez
- Universidade Federal do Rio de Janeiro, Núcleo de Enfrentamento e Estudos de Doenças Infecciosas e Emergentes e Reemergentes, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Orlando da Costa Ferreira
- Universidade Federal do Rio de Janeiro, Núcleo de Enfrentamento e Estudos de Doenças Infecciosas e Emergentes e Reemergentes, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Terezinha Marta Pereira Pinto Castiñeiras
- Universidade Federal do Rio de Janeiro, Núcleo de Enfrentamento e Estudos de Doenças Infecciosas e Emergentes e Reemergentes, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marta Heloísa Lopes
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Moléstias Infecciosas e Parasitárias, São Paulo, São Paulo, Brazil
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Centro de Referência para Imunobiológicos Especiais, São Paulo, São Paulo, Brazil
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Laboratório de Investigação Médica em Imunologia (LIM-48), São Paulo, São Paulo, Brazil
| | - Ana Marli Christovam Sartori
- Universidade de São Paulo, Faculdade de Medicina, Departamento de Moléstias Infecciosas e Parasitárias, São Paulo, São Paulo, Brazil
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Centro de Referência para Imunobiológicos Especiais, São Paulo, São Paulo, Brazil
- Universidade de São Paulo, Faculdade de Medicina, Hospital das Clínicas, Laboratório de Investigação Médica em Imunologia (LIM-48), São Paulo, São Paulo, Brazil
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Povey M, Aris E, Cheuvart B, Hall G, Cohet C, Willame C. Effectiveness of "Priorix" Against Measles and Mumps Diseases in Children Born After 2004 in the United Kingdom: A Retrospective Case-control Study Using the Clinical Practice Research Datalink GOLD Database. Pediatr Infect Dis J 2021; 40:590-596. [PMID: 33956757 PMCID: PMC8104017 DOI: 10.1097/inf.0000000000003111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/01/2021] [Indexed: 11/27/2022]
Abstract
BACKGROUND Evidence on vaccine effectiveness (VE) may encourage vaccination and help fight the reemergence of measles and mumps in Europe. However, limited data exist on real-life effectiveness of individual measles, mumps and rubella (MMR) vaccines. This study evaluated VE of GSK's MMR vaccine ("Priorix") against measles and mumps. METHODS This retrospective, case-control study used UK data from the Clinical Practice Research Datalink GOLD linked to the Hospital Episode Statistics database to identify children 1-13 years old diagnosed with measles or mumps from January 2006 to December 2018. Cases were matched to controls according to birth month/year and practice region. Cases were identified using clinical codes (without laboratory confirmation). "Priorix" exposure was identified using vaccine batch identifiers. Children exposed to other MMR vaccines were excluded. Adjusted VE was estimated for ≥1 vaccine dose in all children, and for 1 dose and ≥2 doses in children ≥4 years at diagnosis. RESULTS Overall, 299 measles cases matched with 1196 controls (87.6% <4 years old), and 243 mumps cases matched with 970 controls (74.2% <4 years old) were considered. VE for ≥1 dose in all children was 78.0% (97.5% confidence interval: 67.2%-85.3%) for measles and 66.7% (48.1%-78.6%) for mumps. In children ≥4 years old, VE after 1 dose was 74.6% (-21.7% to 94.7%) for measles and 82.3% (32.7%-95.3%) for mumps, and VE after ≥2 doses was 94.4% (79.7%-98.5%) for measles and 86.5% (64.0%-94.9%) for mumps. CONCLUSIONS "Priorix" is effective in preventing measles and mumps in real-life settings.
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Affiliation(s)
| | | | | | - Gillian Hall
- Gillian Hall Epidemiology Ltd, London, United Kingdom
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6
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Zmerli O, Chamieh A, Maasri E, Azar E, Afif C. A challenging modified measles outbreak in vaccinated healthcare providers. Infect Prev Pract 2021; 3:100105. [PMID: 34368732 PMCID: PMC8336165 DOI: 10.1016/j.infpip.2020.100105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 12/10/2020] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Modified measles is rarely reported and thought to be an attenuated, less transmissible form of measles. The occupational safety and management of previously immunized healthcare providers (HCP) facing the global reemergence of measles is controversial and unclear.Aim: We report a measles outbreak with an unusual presentation among our vaccinated HCP at Saint George Hospital University Medical Center (SGHUMC) in Lebanon that occurred during a nationwide measles epidemic. METHODS We recorded cases at SGHUMC, a 333-bed tertiary-care center, from April 2018 to June 2018. We established a measles clinic for investigating all febrile patients. HCP exposure was linked to influx of index cases through our Emergency Department. Modified measles was defined as any variation in the classic presentation with a pinpoint/vesicular rash, documented exposure and evidence of prior immunity. We performed serology testing to diagnose and/or document immunity and implemented outbreak controls measures including PPE, airborne isolation, and mass notification. FINDINGS We diagnosed 8 inpatients with classic measles, and 9 affected HCP. We diagnosed 8 HCP with modified measles. One previously immunized HCP developed classic measles despite being immunized and having a positive IgG titer. Our contact tracing revealed a total of 96 exposed HCP with 27 HCP showing non-specific signs of viral illness. We required all the 9 affected HCP to undergo home isolation. CONCLUSION We believe it is a top priority to achieve adequate measles immunity, especially among HCP that are at the frontline of healthcare systems. This necessitates revisiting vaccination schedules and achieving seroprotective titers to reclaim proper herd immunity.
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Affiliation(s)
- Omar Zmerli
- Division of Infectious Diseases, Saint George Hospital University Medical Center, Beirut, Lebanon
- Faculty of Medicine and Medical Sciences, University of Balamand, Beirut, Lebanon
| | - Amanda Chamieh
- Division of Infectious Diseases, Saint George Hospital University Medical Center, Beirut, Lebanon
- Faculty of Medicine and Medical Sciences, University of Balamand, Beirut, Lebanon
- Mediterranean University Hospital Institute for Infectious Diseases, Marseille, 13915, France
| | - Eliane Maasri
- Infection Control Department, Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Eid Azar
- Division of Infectious Diseases, Saint George Hospital University Medical Center, Beirut, Lebanon
- Faculty of Medicine and Medical Sciences, University of Balamand, Beirut, Lebanon
| | - Claude Afif
- Division of Infectious Diseases, Saint George Hospital University Medical Center, Beirut, Lebanon
- Faculty of Medicine and Medical Sciences, University of Balamand, Beirut, Lebanon
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7
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Gibney KB, Attwood LO, Nicholson S, Tran T, Druce J, Healy J, Strachan J, Franklin L, Hall R, Cross GB. Emergence of Attenuated Measles Illness Among IgG-positive/IgM-negative Measles Cases: Victoria, Australia, 2008-2017. Clin Infect Dis 2021; 70:1060-1067. [PMID: 31056637 DOI: 10.1093/cid/ciz363] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Accepted: 04/30/2019] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Waning measles immunity among vaccinated individuals may result in an attenuated illness. This study compares the epidemiological, clinical, and laboratory profile of measles cases with waning immunity with other measles cases. METHODS Polymerase chain reaction-positive (+) measles cases notified to Victoria's Department of Health and Human Services from 2008 to 2017 with immunoglobulin (Ig) M and IgG tested at diagnosis were classified according to serology at diagnosis: IgG negative (-) (nonimmune), IgM+/IgG+ (indeterminate), or IgM-/IgG+ (waning immunity). RESULTS Between 2008 and 2017, 297 measles cases were notified, of whom 190 (64%) were included; 151 of 190 (79%) were nonimmune at diagnosis, 26 (14%) were indeterminate, and 13 (7%) had waning immunity. Between 2008-2013 and 2014-2017, the proportion of cases with waning immunity increased from 0 of 87 (0%) to 13 of 103 (13%) (P < .001) and the diagnostic sensitivity of initial IgM fell from 93% to 81% (P = .012), respectively. Seven (54%) waning immunity cases reported receiving measles-containing vaccines; 1 case had 2 documented doses. Compared with nonimmune and indeterminate cases, waning immunity cases were more likely to be male; less likely to report fever, coryza, and cough; and had lower burden of virus (higher cycle threshold values). Waning immunity cases had higher IgG titers than indeterminate cases (mean optical density values, 1.96 vs 0.71; P = .004). Onward transmission from 1 waning immunity case was documented. CONCLUSIONS Waning immunity among measles cases, associated with secondary vaccine failure and modified clinical illness, is emerging in Victoria with transmission potential.
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Affiliation(s)
- Katherine B Gibney
- Health Protection Branch, Victorian Department of Health and Human Services, Melbourne, Victoria, Australia.,The Peter Doherty Institute for Infection and Immunity, the University of Melbourne and the Royal Melbourne Hospital, Melbourne, Victoria, Australia
| | - Lucy O Attwood
- Department of Infectious Diseases, Alfred Hospital, Melbourne, Victoria, Australia
| | - Suellen Nicholson
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Thomas Tran
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Julian Druce
- Victorian Infectious Diseases Reference Laboratory, Royal Melbourne Hospital at the Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria, Australia
| | - Julia Healy
- Health Protection Branch, Victorian Department of Health and Human Services, Melbourne, Victoria, Australia
| | - Janet Strachan
- Health Protection Branch, Victorian Department of Health and Human Services, Melbourne, Victoria, Australia
| | - Lucinda Franklin
- Health Protection Branch, Victorian Department of Health and Human Services, Melbourne, Victoria, Australia
| | - Robert Hall
- Department of Epidemiology and Preventive Medicine, School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia
| | - Gail B Cross
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore.,Department of Infectious Diseases, National University Hospital, Singapore
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8
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Petraglia TCDMB, Farias PMCDM, Sá GRSE, Santos EMD, Conceição DAD, Maia MDLDS. Vaccine failures: assessing yellow fever, measles, varicella, and mumps vaccines. CAD SAUDE PUBLICA 2020; 36Suppl 2:e00008520. [PMID: 33146313 DOI: 10.1590/0102-311x00008520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 07/06/2020] [Indexed: 11/22/2022] Open
Abstract
Vaccination is one of the greatest public health interventions, based on its safety and effectiveness, but vaccination does not always mean immunization. Numerous aspects related both to the individual that receives the vaccine and the specificity of each vaccine administered are part of the process of obtaining adequate immunization, and it is essential to observe the aspects in order to avoid vaccine failures. The analysis of immunogenicity and effectiveness studies for the measles, varicella, and mumps vaccines point to the need to incorporate two doses into the basic vaccination calendars in order to control these diseases. Epidemiological studies that analyzed outbreaks of these diseases identified cases in individuals that received two doses of the vaccine, which may indicate likely secondary failure. For the yellow fever vaccine, the current discussion lies in the ideal number of doses for individual protection. The World Health Organization recommends a single dose for life. Despite the few reports in the literature concerning vaccine failures, immunogenicity studies demonstrate waning protection over the years, mainly in the pediatric age bracket. In the current scenario of elimination and control of diseases, associated with the decrease in the circulation of the wild-type viruses, the role of epidemiological surveillance is crucial for expanding knowledge on the multiple factors involved, culminating in vaccine failures and the emergence of outbreaks. Outbreaks of vaccine-preventable diseases negatively impact the credibility of immunization programs, leading to low vaccination coverage rates and interfering in vaccination's success.
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Affiliation(s)
| | | | - Glória Regina Silva E Sá
- Instituto de Saúde Coletiva, Universidade Federal do Estado do Rio de Janeiro, Rio de Janeiro, Brasil
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9
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Bennett N, Sutton B, Strachan J, Hoskins A, Malloy MJ, Worth LJ. Measles immunisation status of healthcare workers in smaller Victorian hospitals: can we do better? Aust N Z J Public Health 2020; 44:346-348. [DOI: 10.1111/1753-6405.12989] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 02/01/2020] [Accepted: 03/01/2020] [Indexed: 11/30/2022] Open
Affiliation(s)
- Noleen Bennett
- Victorian Healthcare Associated Infection Surveillance System (VICNISS) Coordinating Centre Doherty Institute for Infection and Immunity Victoria
- Department of Nursing, Melbourne School of Health Sciences The University of Melbourne Victoria
| | - Brett Sutton
- Department of Health and Human Services Victorian State Government
| | - Janet Strachan
- Department of Health and Human Services Victorian State Government
| | - Alex Hoskins
- Victorian Healthcare Associated Infection Surveillance System (VICNISS) Coordinating Centre Doherty Institute for Infection and Immunity Victoria
| | - Michael J. Malloy
- Victorian Healthcare Associated Infection Surveillance System (VICNISS) Coordinating Centre Doherty Institute for Infection and Immunity Victoria
- Centre for Epidemiology and Biostatistics, Melbourne School of Population and Global Health The University of Melbourne Victoria
| | - Leon J. Worth
- Victorian Healthcare Associated Infection Surveillance System (VICNISS) Coordinating Centre Doherty Institute for Infection and Immunity Victoria
- Department of Medicine The University of Melbourne Victoria
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10
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Williamson KM, Merritt T, Durrheim DN. Australia: an island in a sea of measles. Med J Aust 2020; 213:101-103.e1. [DOI: 10.5694/mja2.50650] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Affiliation(s)
- Kirsten M Williamson
- Hunter New England Local Health District Newcastle NSW
- Australian National University Canberra ACT
| | - Tony Merritt
- Hunter New England Local Health District Newcastle NSW
| | - David N Durrheim
- Hunter New England Local Health District Newcastle NSW
- University of Newcastle Newcastle NSW
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11
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Gianfredi V, Moretti M, Fusco Moffa I. Burden of measles using disability-adjusted life years, Umbria 2013-2018. ACTA BIO-MEDICA : ATENEI PARMENSIS 2020; 91:48-54. [PMID: 32275267 PMCID: PMC7975903 DOI: 10.23750/abm.v91i3-s.9412] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 03/24/2020] [Indexed: 11/23/2022]
Abstract
Background and aim: The low measles vaccination coverage contributes to the re-emerging of measles in Italy. This study aimed to estimate the measles burden, expressed in Disability Adjusted Life Years (DALYs), in Umbria, for the period 2013-2018. Methods: Data on measles cases in Umbria were obtained from the MoRoNet. While data related to the resident population, were obtained from the website of the National Institute of Statistics. The estimated DALYs was calculated using the Burden of Communicable Diseases in Europe toolkit. The results are expressed in DALYs per year, per case and per 100,000 subjects, for acute illness and for sequelae. Results: The estimated incidence in mean for the entire period was 52.50 cases per year. Resulting in an average loss of 3.10 DALYs per year. Conclusions: The data obtained from this analysis provide important information on the impact of measles in the Umbria region, and offer useful data to the Health Authorities that can be used to reduce measles incidence in the region.
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Affiliation(s)
- Vincenza Gianfredi
- Post graduate School of Hygiene and Public Health, Department of Experimental Medicine, University of Perugia..
| | - Massimo Moretti
- Department of Pharmaceutical Science, University of Perugia, Perugia, Italy.
| | - Igino Fusco Moffa
- Local Health Unit Umbria 1, Department of Prevention, Travel Medicine Unit, Perugia, Italy .
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Hughes SL, Bolotin S, Khan S, Li Y, Johnson C, Friedman L, Tricco AC, Hahné SJM, Heffernan JM, Dabbagh A, Durrheim DN, Orenstein WA, Moss WJ, Jit M, Crowcroft NS. The effect of time since measles vaccination and age at first dose on measles vaccine effectiveness - A systematic review. Vaccine 2020; 38:460-469. [PMID: 31732326 PMCID: PMC6970218 DOI: 10.1016/j.vaccine.2019.10.090] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Revised: 09/16/2019] [Accepted: 10/27/2019] [Indexed: 12/04/2022]
Abstract
BACKGROUND In settings where measles has been eliminated, vaccine-derived immunity may in theory wane more rapidly due to a lack of immune boosting by circulating measles virus. We aimed to assess whether measles vaccine effectiveness (VE) waned over time, and if so, whether differentially in measles-eliminated and measles-endemic settings. METHODS We performed a systematic literature review of studies that reported VE and time since vaccination with measles-containing vaccine (MCV). We extracted information on case definition (clinical symptoms and/or laboratory diagnosis), method of vaccination status ascertainment (medical record or vaccine registry), as well as any biases which may have arisen from cold chain issues and a lack of an age at first dose of MCV. We then used linear regression to evaluate VE as a function of age at first dose of MCV and time since MCV. RESULTS After screening 14,782 citations, we identified three full-text articles from measles-eliminated settings and 33 articles from measles-endemic settings. In elimination settings, two-dose VE estimates increased as age at first dose of MCV increased and decreased as time since MCV increased; however, the small number of studies available limited interpretation. In measles-endemic settings, one-dose VE increased by 1.5% (95% CI 0.5, 2.5) for every month increase in age at first dose of MCV. We found no evidence of waning VE in endemic settings. CONCLUSIONS The paucity of data from measles-eliminated settings indicates that additional studies and approaches (such as studies using proxies including laboratory correlates of protection) are needed to answer the question of whether VE in measles-eliminated settings wanes. Age at first dose of MCV was the most important factor in determining VE. More VE studies need to be conducted in elimination settings, and standards should be developed for information collected and reported in such studies.
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Affiliation(s)
| | - Shelly Bolotin
- Public Health Ontario, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada
| | | | - Ye Li
- Public Health Ontario, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | | | | | - Andrea C Tricco
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada
| | - Susan J M Hahné
- Centre for Infectious Disease Control, National Institute for Public Health and the Environment, Bilthoven, the Netherlands
| | - Jane M Heffernan
- Centre for Disease Modelling, Department of Mathematics & Statistics, York University, Toronto, Ontario, Canada
| | - Alya Dabbagh
- Department of Immunisation, Vaccines, and Biologicals, World Health Organization, Geneva, Switzerland
| | - David N Durrheim
- Hunter New England Health, New Lambton Heights, New South Wales, Australia; School of Medicine and Public Health, University of Newcastle, New South Wales, Australia; Public Health and Tropical Medicine, James Cook University, Queensland, Australia
| | - Walter A Orenstein
- Emory University School of Medicine, Emory University, Atlanta, GA, United States; Emory Vaccine Center, Emory University, Atlanta, GA, United States
| | - William J Moss
- International Vaccine Access Center, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, United States
| | - Mark Jit
- Department of Infectious Disease Epidemiology, Faculty of Epidemiology and Population Health, London School of Hygiene and Tropical Medicine, London, United Kingdom; Modelling and Economics Unit, Public Health England, London, United Kingdom
| | - Natasha S Crowcroft
- Public Health Ontario, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada; ICES, Toronto, Ontario, Canada.
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Javelle E, Colson P, Parola P, Raoult D. Measles, the need for a paradigm shift. Eur J Epidemiol 2019; 34:897-915. [DOI: 10.1007/s10654-019-00569-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 10/03/2019] [Indexed: 01/24/2023]
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Measles Elimination: Identifying Susceptible Sub-Populations to Tailor Immunization Strategies. Viruses 2019; 11:v11080765. [PMID: 31434243 PMCID: PMC6723762 DOI: 10.3390/v11080765] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 08/14/2019] [Accepted: 08/16/2019] [Indexed: 11/21/2022] Open
Abstract
Measles elimination has been identified as a public health priority in Europe for a long time but has not yet been achieved. The World Health Organization (WHO) recommends identification of susceptible sub-populations to target supplementary immunization activities. We used three different sources of information: retrospective samples investigated for measles IgG between 1997 and 2016, vaccine coverage data from the existing electronic registry for birth cohorts 2015 to 1999, and surveillance data from 2009 until 20 July 2019. We calculated susceptibility by birth cohort using seroprevalence data, adjusting vaccine coverage data with reported effectiveness (93% for the first and 97% for the second dose, respectively), and compared it with measles incidence data, aggregated by birth cohorts and districts. Susceptibility levels for persons 10–41 years (birth cohorts 2007–1976) were 10.4% and thus far above the recommended values of WHO (5%). Older birth cohorts were sufficiently protected. Districts with the highest susceptibility estimates corresponded with districts with the highest incidence rates. Birth cohorts with susceptibility levels > 10% showed a 4.7 increased relative risk of having had more than one measles case. We conclude that retrospective serosurveys are a cheap and useful approach in identifying susceptible sub-populations, especially for older birth cohorts whose coverage data remain scarce.
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Assessment of Routine Measles Vaccine Effectiveness Among Children Referring to Tertiary Fever Hospital in Egypt. ARCHIVES OF PEDIATRIC INFECTIOUS DISEASES 2019. [DOI: 10.5812/pedinfect.90407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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16
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Trojanowski M, Stanforth E, Hong J, Khung R, Nersesian PV. Addressing the resurgence of measles and vaccine refusal in the United States through public health nursing. Public Health Nurs 2019; 36:449-450. [DOI: 10.1111/phn.12639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Revised: 06/17/2019] [Accepted: 06/21/2019] [Indexed: 12/01/2022]
Affiliation(s)
- Midori Trojanowski
- MSN Entry to Nursing Practice Program; Johns Hopkins School of Nursing; Baltimore Maryland
| | - Emily Stanforth
- MSN Entry to Nursing Practice Program; Johns Hopkins School of Nursing; Baltimore Maryland
| | - Jane Hong
- MSN Entry to Nursing Practice Program; Johns Hopkins School of Nursing; Baltimore Maryland
| | - Robyn Khung
- MSN Entry to Nursing Practice Program; Johns Hopkins School of Nursing; Baltimore Maryland
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Masters NB, Wagner AL, Ding Y, Zhang Y, Boulton ML. Assessing measles vaccine failure in Tianjin, China. Vaccine 2019; 37:3251-3254. [PMID: 31078327 DOI: 10.1016/j.vaccine.2019.05.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 04/30/2019] [Accepted: 05/02/2019] [Indexed: 11/29/2022]
Abstract
Despite increasing global measles vaccination coverage, progress toward measles elimination has slowed in recent years. In China, children receive a measles-containing vaccine (MCV) at 8 months, 18-24 months, and some urban areas offer a third dose at age 4-6 years. However, substantial measles cases in Tianjin, China, occur among individuals who have received multiple MCV doses. This study describes the vaccination history of measles cases 8 months - 19 years old. Data came from measles cases in Tianjin's reportable disease surveillance system (2009-2013), and from a case control study (2011-2015). Twenty-nine percent of those in the surveillance dataset and 54.4% of those in the case series received at least one dose of MCV. The minimum and median time-to-diagnosis since vaccination revealed an increase in time since vaccination for incremental doses. Considerable measles cases in Tianjin occur in vaccinated children, and further research is needed to understand the reasons for vaccine failure.
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Affiliation(s)
- Nina B Masters
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA.
| | - Abram L Wagner
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
| | - Yaxing Ding
- Division of Expanded Programs On Immunization, Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - Ying Zhang
- Division of Expanded Programs On Immunization, Tianjin Centers for Disease Control and Prevention, Tianjin 300011, China
| | - Matthew L Boulton
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
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Wedlock PT, Mitgang EA, Oron AP, Hagedorn BL, Leonard J, Brown ST, Bakal J, Siegmund SS, Lee BY. Modeling the economic impact of different vial-opening thresholds for measles-containing vaccines. Vaccine 2019; 37:2356-2368. [PMID: 30914223 PMCID: PMC6467546 DOI: 10.1016/j.vaccine.2019.03.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 03/07/2019] [Accepted: 03/11/2019] [Indexed: 10/27/2022]
Abstract
INTRODUCTION The lack of specific policies on how many children must be present at a vaccinating location before a healthcare worker can open a measles-containing vaccine (MCV) - i.e. the vial-opening threshold - has led to inconsistent practices, which can have wide-ranging systems effects. METHODS Using HERMES-generated simulation models of the routine immunization supply chains of Benin, Mozambique and Niger, we evaluated the impact of different vial-opening thresholds (none, 30% of doses must be used, 60%) and MCV presentations (10-dose, 5-dose) on each supply chain. We linked these outputs to a clinical- and economic-outcomes model which translated the change in vaccine availability to associated infections, medical costs, and DALYs. We calculated the economic impact of each policy from the health system perspective. RESULTS The vial-opening threshold that maximizes vaccine availability while minimizing costs varies between individual countries. In Benin (median session size = 5), implementing a 30% vial-opening threshold and tailoring distribution of 10-dose and 5-dose MCVs to clinics based on session size is the most cost-effective policy, preventing 671 DALYs ($471/DALY averted) compared to baseline (no threshold, 10-dose MCVs). In Niger (median MCV session size = 9), setting a 60% vial-opening threshold and tailoring MCV presentations is the most cost-effective policy, preventing 2897 DALYs ($16.05/ DALY averted). In Mozambique (median session size = 3), setting a 30% vial-opening threshold using 10-dose MCVs is the only beneficial policy compared to baseline, preventing 3081 DALYs ($85.98/DALY averted). Across all three countries, however, a 30% vial-opening threshold using 10-dose MCVs everywhere is the only MCV threshold that consistently benefits each system compared to baseline. CONCLUSION While the ideal vial-opening threshold policy for MCV varies by supply chain, implementing a 30% vial-opening threshold for 10-dose MCVs benefits each system by improving overall vaccine availability and reducing associated medical costs and DALYs compared to no threshold.
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Affiliation(s)
- Patrick T Wedlock
- HERMES Logistics Modeling Team, Baltimore, MD & Pittsburgh, PA, United States; Global Obesity Prevention Center (GOPC) at Johns Hopkins University, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Elizabeth A Mitgang
- HERMES Logistics Modeling Team, Baltimore, MD & Pittsburgh, PA, United States; Global Obesity Prevention Center (GOPC) at Johns Hopkins University, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Assaf P Oron
- Institute for Disease Modeling, Bellevue, WA, United States
| | | | - Jim Leonard
- HERMES Logistics Modeling Team, Baltimore, MD & Pittsburgh, PA, United States; Pittsburgh Supercomputing Center, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Shawn T Brown
- HERMES Logistics Modeling Team, Baltimore, MD & Pittsburgh, PA, United States; McGill Centre for Integrative Neuroscience, McGill Neurological Institute, McGill University, Montreal, Canada
| | - Jennifer Bakal
- HERMES Logistics Modeling Team, Baltimore, MD & Pittsburgh, PA, United States; Pittsburgh Supercomputing Center, Carnegie Mellon University, Pittsburgh, PA, United States
| | - Sheryl S Siegmund
- HERMES Logistics Modeling Team, Baltimore, MD & Pittsburgh, PA, United States; Global Obesity Prevention Center (GOPC) at Johns Hopkins University, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States
| | - Bruce Y Lee
- HERMES Logistics Modeling Team, Baltimore, MD & Pittsburgh, PA, United States; Global Obesity Prevention Center (GOPC) at Johns Hopkins University, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, United States.
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Musa S, Topalović B, Ćatić S, Smajlagić Z. Assessment of vaccine effectiveness during measles outbreak in the Federation of Bosnia and Herzegovina, 2014-2015. Cent Eur J Public Health 2018; 26:79-82. [PMID: 30102493 DOI: 10.21101/cejph.a4754] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2016] [Accepted: 04/09/2018] [Indexed: 11/15/2022]
Abstract
OBJECTIVE Between February 2014 and September 2015 a large measles outbreak (5,084 cases) occurred in the Federation of Bosnia and Herzegovina (FB&H). The aim of this study is to assess the effectiveness of routine measles vaccination in the FB&H. METHODS We conducted an analysis of the resurgence period surveillance data and a retrospective cohort study involving primary school aged children in randomly selected schools. RESULTS Measles cases occurred among all age groups, mostly among the unvaccinated. Among fully immunized, 2.1% contracted measles. Measles vaccine effectiveness was high. The study indicates that one dose reduced the risk for measles by 91.9% (95% CI: 81.4-96.4%), two doses reduced the risk by 97.3% (95% CI: 95.5-98.4%). No evidence of waning immunity was found. Our survey reveals that a significant number of children had no immunization status registered. CONCLUSIONS The results of this study suggest that the resurgence was likely caused by an accumulation of measles-susceptible children not being vaccinated. This vaccine effectiveness study does not support possible vaccination failure as a contributing factor.
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Affiliation(s)
- Sanjin Musa
- Department of Epidemiology, Institute of Public Health of the Federation of Bosnia and Herzegovina, Sarajevo, Bosnia and Herzegovina
| | - Blaško Topalović
- Department of Epidemiology, Institute of Public Health of Tuzla Canton, Tuzla, Bosnia and Herzegovina
| | - Sutka Ćatić
- Department of Hygiene and Epidemiology, Health Care Centre, Bugojno, Bosnia and Herzegovina
| | - Zijada Smajlagić
- Department of Hygiene and Epidemiology, Health Care Centre, Visoko, Bosnia and Herzegovina
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Quinn HE, Gidding HF, Marshall HS, Booy R, Elliott EJ, Richmond P, Crawford N, McIntyre PB, Macartney KK. Varicella vaccine effectiveness over 10 years in Australia; moderate protection from 1-dose program. J Infect 2018; 78:220-225. [PMID: 30528868 DOI: 10.1016/j.jinf.2018.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 09/25/2018] [Accepted: 11/18/2018] [Indexed: 10/27/2022]
Abstract
OBJECTIVES To examine the impact of Australia's single dose infant varicella vaccination program, we assessed single dose varicella vaccine effectiveness (VE) in preventing hospitalised disease using two methods. METHODS Clinically confirmed varicella cases from the Paediatric Active Enhanced Disease Surveillance (PAEDS) sentinel network were age-matched to 20 controls obtained from the Australian Immunisation Register. Conditional logistic regression models were used to estimate VE and compared with estimates obtained using our second approach. RESULTS There were 78 hospitalised varicella cases during the post vaccine introduction period from January 2008 to December 2015, who were eligible for funded varicella vaccination. Median age at onset was 4.5 years and more than half (59%) were vaccinated. The majority of children received one vaccine brand (Varilrix, GSK). The estimated case-control VE for one dose of vaccine against hospitalised varicella was 64.7% (95% CI: 43.3-78.0%); estimates using the screening method were not significantly different. Exclusion of children who were immunocompromised did not significantly alter VE estimates. CONCLUSIONS Although Australia's program has impacted on the burden of varicella disease, single dose VE against varicella hospitalisation is only moderate. Greater reductions in varicella disease could potentially be achieved by incorporation of a second vaccine dose into the program to minimise breakthrough disease and interrupt virus circulation.
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Affiliation(s)
- Helen E Quinn
- National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), Children's Hospital at Westmead, Cnr Hawkesbury Road and Hainsworth Street, Westmead, NSW 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, Australia.
| | - Heather F Gidding
- National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), Children's Hospital at Westmead, Cnr Hawkesbury Road and Hainsworth Street, Westmead, NSW 2145, Australia; School of Public Health and Community Medicine, UNSW Medicine, University of New South Wales, Sydney, Australia
| | - Helen S Marshall
- Vaccinology and Immunology Research Trials Unit, Women's and Children's Health Network, Adelaide, Australia; Robinson Research Institute and School of Medicine, University of Adelaide, Adelaide, Australia
| | - Robert Booy
- National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), Children's Hospital at Westmead, Cnr Hawkesbury Road and Hainsworth Street, Westmead, NSW 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, Australia; Children's Hospital at Westmead, Sydney, Australia
| | - Elizabeth J Elliott
- Discipline of Child and Adolescent Health, University of Sydney, Sydney, Australia; Children's Hospital at Westmead, Sydney, Australia; Australian Paediatric Surveillance Unit, Westmead, Australia
| | - Peter Richmond
- Wesfarmer's Centre for Vaccines and Infectious Diseases, Telethon Kids Institute, Perth, Australia
| | - Nigel Crawford
- Murdoch Children's Research Institute, Parkville, Australia; Royal Children's Hospital, Melbourne, Australia; Department of Paediatrics, The University of Melbourne, Australia
| | - Peter B McIntyre
- National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), Children's Hospital at Westmead, Cnr Hawkesbury Road and Hainsworth Street, Westmead, NSW 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, Australia; Children's Hospital at Westmead, Sydney, Australia
| | - Kristine K Macartney
- National Centre for Immunisation Research and Surveillance of Vaccine Preventable Diseases (NCIRS), Children's Hospital at Westmead, Cnr Hawkesbury Road and Hainsworth Street, Westmead, NSW 2145, Australia; Discipline of Child and Adolescent Health, University of Sydney, Sydney, Australia; Children's Hospital at Westmead, Sydney, Australia
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Gidding HF, Quinn HE, Hueston L, Dwyer DE, McIntyre PB. Declining measles antibodies in the era of elimination: Australia's experience. Vaccine 2017; 36:507-513. [PMID: 29269156 DOI: 10.1016/j.vaccine.2017.12.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 11/29/2017] [Accepted: 12/01/2017] [Indexed: 11/17/2022]
Abstract
BACKGROUND Australia is one of only a few countries with a long-standing and consistent serosurveillance program. We conducted a national serosurvey in 2012-2013 to estimate population seroprevalence of measles-specific IgG and the effective reproduction number, R, and compare the results with the three previous serosurveys (1996-1999, 2002 and 2007) to examine trends following a decade of sustained measles control. METHODS 2729 residual sera from 1 to 49 year olds were tested using the Enzygnost anti-measles IgG enzyme immunoassay (EIA). All sera in the equivocal range by EIA on re-testing and a random sample of low positive and negative sera were later tested by a microneutralisation assay. R was calculated from weighted estimates of the proportion seronegative by age using a previously developed contact matrix. RESULTS In the 2012-13 serosurvey, anti-measles IgG seropositivity for 1-49 year olds was 80.8% (95% CI: 79.4-82.3%) and 8.9% (95% CI: 7.8-10.0%) had equivocal antibody levels. The increasing proportion of seronegative and equivocal individuals in age groups 10-39 years continued a trend seen in previous serosurveys. There was also an increase in equivocal results among 2-4 and 5-9 year old children, >90% of whom were recently vaccinated. R increased from 0.57 in 1999 to above the epidemic threshold of 1 in 2012-13 (R = 1.7). All 20 EIA negative sera, 238/241 (98.8%) equivocal sera, and 89/92 (96.7%) low positive sera had a titre <10 (negative) in the measles microneutralisation assay. CONCLUSIONS A number of countries with sustained measles control have now demonstrated that measles-specific IgG antibodies decline with time since vaccination. As there is good epidemiologic evidence of population-level protection, the implications of declining measles-specific IgG antibody levels for maintaining measles elimination are unclear. Novel studies to determine correlates of protection against measles transmission and disease in the post-elimination era are needed to help answer this question.
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Affiliation(s)
- Heather F Gidding
- School of Public Health and Community Medicine, UNSW Medicine, The University of New South Wales, Sydney, NSW, Australia; National Centre for Immunisation Research and Surveillance, Westmead, NSW, Australia.
| | - Helen E Quinn
- National Centre for Immunisation Research and Surveillance, Westmead, NSW, Australia.
| | - Linda Hueston
- Centre for Infectious Diseases and Microbiology Laboratory Services, New South Wales Health Pathology-Institute of Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW, Australia.
| | - Dominic E Dwyer
- Centre for Infectious Diseases and Microbiology Laboratory Services, New South Wales Health Pathology-Institute of Clinical Pathology and Medical Research, Westmead Hospital, Westmead, NSW, Australia.
| | - Peter B McIntyre
- National Centre for Immunisation Research and Surveillance, Westmead, NSW, Australia.
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Neave PE, Heywood AE, Gibney KB, Leder K. Imported infections: What information should be collected by surveillance systems to inform public health policy? Travel Med Infect Dis 2016; 14:350-9. [PMID: 27235839 PMCID: PMC7110684 DOI: 10.1016/j.tmaid.2016.05.007] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2015] [Revised: 05/10/2016] [Accepted: 05/17/2016] [Indexed: 11/17/2022]
Abstract
Background International travel carries the risk of imported diseases, which are an increasingly significant public health problem. There is little guidance about which variables should be collected by surveillance systems for strategy-based surveillance. Methods Surveillance forms for dengue, malaria, hepatitis A, typhoid and measles were collected from Australia and New Zealand and information on these compared with national surveillance forms from the UK and Canada by travel health experts. Variables were categorised by information relating to recent travel, demographics and disease severity. Results Travel-related information most commonly requested included country of travel, vaccination status and travel dates. In Australia, ethnicity information requested related to indigenous status, whilst in New Zealand it could be linked to census categories. Severity of disease information most frequently collected were hospitalisation and death. Conclusions Reviewing the usefulness of variables collected resulted in the recommendation that those included should be: overseas travel, reason for travel, entry and departure dates during the incubation period, vaccination details, traveller's and/or parents' country of birth, country of usual residence, time resident in current country, postcode, hospitalisation and death details. There was no agreement about whether ethnicity details should be collected. The inclusion of these variables on surveillance forms could enable imported infection-related policy to be formulated nationally and internationally.
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Affiliation(s)
- Penny E Neave
- School of Public Health and Psychosocial Studies, Auckland University of Technology, 90, Akoranga Drive, Northcote, Auckland, New Zealand.
| | - Anita E Heywood
- School of Public Health and Community Medicine, University of New South Wales, Kensington, New South Wales, Australia.
| | - Katherine B Gibney
- School of Public Health and Preventive Medicine, The Alfred Centre, Monash University, Commercial Road, Melbourne, Victoria, Australia.
| | - Karin Leder
- School of Public Health and Preventive Medicine, The Alfred Centre, Monash University, Commercial Road, Melbourne, Victoria, Australia.
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