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Shattock AJ, Johnson HC, Sim SY, Carter A, Lambach P, Hutubessy RCW, Thompson KM, Badizadegan K, Lambert B, Ferrari MJ, Jit M, Fu H, Silal SP, Hounsell RA, White RG, Mosser JF, Gaythorpe KAM, Trotter CL, Lindstrand A, O'Brien KL, Bar-Zeev N. Contribution of vaccination to improved survival and health: modelling 50 years of the Expanded Programme on Immunization. Lancet 2024; 403:2307-2316. [PMID: 38705159 PMCID: PMC11140691 DOI: 10.1016/s0140-6736(24)00850-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2024] [Revised: 04/18/2024] [Accepted: 04/22/2024] [Indexed: 05/07/2024]
Abstract
BACKGROUND WHO, as requested by its member states, launched the Expanded Programme on Immunization (EPI) in 1974 to make life-saving vaccines available to all globally. To mark the 50-year anniversary of EPI, we sought to quantify the public health impact of vaccination globally since the programme's inception. METHODS In this modelling study, we used a suite of mathematical and statistical models to estimate the global and regional public health impact of 50 years of vaccination against 14 pathogens in EPI. For the modelled pathogens, we considered coverage of all routine and supplementary vaccines delivered since 1974 and estimated the mortality and morbidity averted for each age cohort relative to a hypothetical scenario of no historical vaccination. We then used these modelled outcomes to estimate the contribution of vaccination to globally declining infant and child mortality rates over this period. FINDINGS Since 1974, vaccination has averted 154 million deaths, including 146 million among children younger than 5 years of whom 101 million were infants younger than 1 year. For every death averted, 66 years of full health were gained on average, translating to 10·2 billion years of full health gained. We estimate that vaccination has accounted for 40% of the observed decline in global infant mortality, 52% in the African region. In 2024, a child younger than 10 years is 40% more likely to survive to their next birthday relative to a hypothetical scenario of no historical vaccination. Increased survival probability is observed even well into late adulthood. INTERPRETATION Since 1974 substantial gains in childhood survival have occurred in every global region. We estimate that EPI has provided the single greatest contribution to improved infant survival over the past 50 years. In the context of strengthening primary health care, our results show that equitable universal access to immunisation remains crucial to sustain health gains and continue to save future lives from preventable infectious mortality. FUNDING WHO.
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Affiliation(s)
- Andrew J Shattock
- Swiss Tropical and Public Health Institute, Basel, Switzerland; University of Basel, Basel, Switzerland; Telethon Kids Institute, Perth, Australia; University of Western Australia, Perth, Australia
| | - Helen C Johnson
- Safinea, London, UK; London School of Economics and Political Science, London, UK; London School of Hygiene & Tropical Medicine, London, UK; University of Cambridge, Cambridge, UK
| | - So Yoon Sim
- World Health Organization, Geneva, Switzerland
| | | | | | | | | | | | - Brian Lambert
- Pennsylvania State University, University Park, PA, USA
| | | | - Mark Jit
- London School of Hygiene & Tropical Medicine, London, UK
| | - Han Fu
- London School of Hygiene & Tropical Medicine, London, UK
| | - Sheetal P Silal
- Modelling and Simulation Hub, Africa, Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa; Centre for Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | - Rachel A Hounsell
- Modelling and Simulation Hub, Africa, Department of Statistical Sciences, University of Cape Town, Cape Town, South Africa; Centre for Global Health, Nuffield Department of Medicine, Oxford University, Oxford, UK
| | - Richard G White
- London School of Hygiene & Tropical Medicine, London, UK; TB Modelling Group, Infectious Disease Epidemiology Department, London School of Hygiene & Tropical Medicine, London, UK
| | | | | | - Caroline L Trotter
- University of Cambridge, Cambridge, UK; Imperial College London, London, UK
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Adigweme I, Yisa M, Ooko M, Akpalu E, Bruce A, Donkor S, Jarju LB, Danso B, Mendy A, Jeffries D, Segonds-Pichon A, Njie A, Crooke S, El-Badry E, Johnstone H, Royals M, Goodson JL, Prausnitz MR, McAllister DV, Rota PA, Henry S, Clarke E. A measles and rubella vaccine microneedle patch in The Gambia: a phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial. Lancet 2024; 403:1879-1892. [PMID: 38697170 PMCID: PMC11099471 DOI: 10.1016/s0140-6736(24)00532-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 02/28/2024] [Accepted: 03/12/2024] [Indexed: 05/04/2024]
Abstract
BACKGROUND Microneedle patches (MNPs) have been ranked as the highest global priority innovation for overcoming immunisation barriers in low-income and middle-income countries. This trial aimed to provide the first data on the tolerability, safety, and immunogenicity of a measles and rubella vaccine (MRV)-MNP in children. METHODS This single-centre, phase 1/2, double-blind, double-dummy, randomised, active-controlled, age de-escalation trial was conducted in The Gambia. To be eligible, all participants had to be healthy according to prespecified criteria, aged 18-40 years for the adult cohort, 15-18 months for toddlers, or 9-10 months for infants, and to be available for visits throughout the follow-up period. The three age cohorts were randomly assigned in a 2:1 ratio (adults) or 1:1 ratio (toddlers and infants) to receive either an MRV-MNP (Micron Biomedical, Atlanta, GA, USA) and a placebo (0·9% sodium chloride) subcutaneous injection, or a placebo-MNP and an MRV subcutaneous injection (MRV-SC; Serum Institute of India, Pune, India). Unmasked staff ransomly assigned the participants using an online application, and they prepared visually identical preparations of the MRV-MNP or placebo-MNP and MRV-SC or placebo-SC, but were not involved in collecting endpoint data. Staff administering the study interventions, participants, parents, and study staff assessing trial endpoints were masked to treatment allocation. The safety population consists of all vaccinated participants, and analysis was conducted according to route of MRV administration, irrespective of subsequent protocol deviations. The immunogenicity population consisted of all vaccinated participants who had a baseline and day 42 visit result available, and who had no protocol deviations considered to substantially affect the immunogenicity endpoints. Solicited local and systemic adverse events were collected for 14 days following vaccination. Unsolicited adverse events were collected to day 180. Age de-escalation between cohorts was based on the review of the safety data to day 14 by an independent data monitoring committee. Serum neutralising antibodies to measles and rubella were measured at baseline, day 42, and day 180. Analysis was descriptive and included safety events, seroprotection and seroconversion rates, and geometric mean antibody concentrations. The trial was registered with the Pan African Clinical Trials Registry PACTR202008836432905, and is complete. FINDINGS Recruitment took place between May 18, 2021, and May 27, 2022. 45 adults, 120 toddlers, and 120 infants were randomly allocated and vaccinated. There were no safety concerns in the first 14 days following vaccination in either adults or toddlers, and age de-escalation proceeded accordingly. In infants, 93% (52/56; 95% CI 83·0-97·2) seroconverted to measles and 100% (58/58; 93·8-100) seroconverted to rubella following MRV-MNP administration, while 90% (52/58; 79·2-95·2) and 100% (59/59; 93·9-100) seroconverted to measles and rubella respectively, following MRV-SC. Induration at the MRV-MNP application site was the most frequent local reaction occurring in 46 (77%) of 60 toddlers and 39 (65%) of 60 infants. Related unsolicited adverse events, most commonly discolouration at the application site, were reported in 35 (58%) of 60 toddlers and 57 (95%) of 60 infants that had received the MRV-MNP. All local reactions were mild. There were no related severe or serious adverse events. INTERPRETATION The safety and immunogenicity data support the accelerated development of the MRV-MNP. FUNDING Bill & Melinda Gates Foundation.
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Affiliation(s)
- Ikechukwu Adigweme
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Mohammed Yisa
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Michael Ooko
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Edem Akpalu
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Andrew Bruce
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Simon Donkor
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Lamin B Jarju
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Baba Danso
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Anthony Mendy
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - David Jeffries
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Anne Segonds-Pichon
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Abdoulie Njie
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia
| | - Stephen Crooke
- Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Elina El-Badry
- Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - James L Goodson
- Global Immunization Division, Global Health Center, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | | | - Paul A Rota
- Division of Viral Diseases, National Center for Immunization and Respiratory Diseases, Centers for Disease Control and Prevention, Atlanta, GA, USA
| | | | - Ed Clarke
- Vaccines and Immunity Theme, Medical Research Council Unit The Gambia at the London School of Hygiene & Tropical Medicine, Banjul, The Gambia.
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Davila-Payan CS, Hill A, Kayembe L, Alexander JP, Lynch M, Pallas SW. Analysis of the yearly transition function in measles disease modeling. Stat Med 2024; 43:435-451. [PMID: 38100282 DOI: 10.1002/sim.9951] [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: 05/10/2022] [Revised: 10/03/2023] [Accepted: 10/16/2023] [Indexed: 12/17/2023]
Abstract
Globally, there were an estimated 9.8 million measles cases and 207 500 measles deaths in 2019. As the effort to eliminate measles around the world continues, modeling remains a valuable tool for public health decision-makers and program implementers. This study presents a novel approach to the use of a yearly transition function that formulates mathematically the vaccine schedules for different age groups while accounting for the effects of the age of vaccination, the timing of vaccination, and disease seasonality on the yearly number of measles cases in a country. The methodology presented adds to an existing modeling framework and expands its analysis, making its utilization more adjustable for the user and contributing to its conceptual clarity. This article also adjusts for the temporal interaction between vaccination and exposure to disease, applying adjustments to estimated yearly counts of cases and the number of vaccines administered that increase population immunity. These new model features provide the ability to forecast and compare the effects of different vaccination timing scenarios and seasonality of transmission on the expected disease incidence. Although the work presented is applied to the example of measles, it has potential relevance to modeling other vaccine-preventable diseases.
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Affiliation(s)
- C S Davila-Payan
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - A Hill
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - L Kayembe
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - J P Alexander
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - M Lynch
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
| | - S W Pallas
- Global Immunization Division, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Auzenbergs M, Fu H, Abbas K, Procter SR, Cutts FT, Jit M. Health effects of routine measles vaccination and supplementary immunisation activities in 14 high-burden countries: a Dynamic Measles Immunization Calculation Engine (DynaMICE) modelling study. Lancet Glob Health 2023; 11:e1194-e1204. [PMID: 37474227 PMCID: PMC10369016 DOI: 10.1016/s2214-109x(23)00220-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 04/17/2023] [Accepted: 05/02/2023] [Indexed: 07/22/2023]
Abstract
BACKGROUND WHO recommends at least 95% population coverage with two doses of measles-containing vaccine (MCV). Most countries worldwide use routine services to offer a first dose of measles-containing vaccine (MCV1) and later, a second dose of measles-containing vaccine (MCV2). Many countries worldwide conduct supplementary immunisation activities (SIAs), offering vaccination to all people in a specific age range irrespective of previous vaccination history. We aimed to estimate the relative effects of each dose and delivery route in 14 countries with high measles burden. METHODS We used an age-structured compartmental dynamic model, the Dynamic Measles Immunization Calculation Engine (DynaMICE), to assess the effects of different vaccination strategies on measles susceptibility and burden during 2000-20 in 14 countries with high measles incidence (containing 53% of the global birth cohort and 78% of the global measles burden). Country-specific routine MCV1 and MCV2 coverage data during 1980-2020 were obtained from the WHO and UNICEF Estimates of National Immunization Coverage database for all modelled countries and SIA data were obtained from the WHO summary of measles and rubella SIAs. We estimated the incremental health effects of different vaccination strategies using prevented cases of measles and deaths from measles and their efficiency using the incremental number needed to vaccinate (NNV) to prevent an additional measles case. FINDINGS Compared with no vaccination, MCV1 implementation was estimated to have prevented 824 million cases of measles and 9·6 million deaths from measles, with a median NNV of 1·41 (IQR 1·35-1·44). Adding routine MCV2 to MCV1 was estimated to have prevented 108 million cases and 404 270 deaths, whereas adding SIAs to MCV1 was estimated to have prevented 256 million cases and 4·4 million deaths. Despite larger incremental effects, adding SIAs to MCV1 (median incremental NNV 6·02, 5·30-7·68) showed reduced efficiency compared with adding routine MCV2 (5·41, 4·76-6·11). INTERPRETATION Vaccination strategies, including non-selective SIAs, reach a greater proportion of children who are unvaccinated and reduce measles burden more than MCV2 alone, but efficiency is lower because of the wide age range targeted by SIAs. This analysis provides information to help improve the health effects and efficiency of measles vaccination strategies. The interplay between MCV1, MCV2, and SIAs should be considered when planning future measles vaccination strategies. FUNDING Gavi, the Vaccine Alliance and the Bill & Melinda Gates Foundation.
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Affiliation(s)
- Megan Auzenbergs
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
| | - Han Fu
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Kaja Abbas
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; Public Health Foundation of India, New Delhi, India
| | - Simon R Procter
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Felicity T Cutts
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Mark Jit
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK; School of Public Health, University of Hong Kong, Hong Kong Special Administrative Region, China
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Exploring the subnational inequality and heterogeneity of the impact of routine measles immunisation in Africa. Vaccine 2022; 40:6806-6817. [PMID: 36244882 DOI: 10.1016/j.vaccine.2022.09.049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 11/07/2022]
Abstract
Despite vaccination being one of the most effective public health interventions, there are persisting inequalities and inequities in immunisation. Understanding the differences in subnational vaccine impact can help improve delivery mechanisms and policy. We analyse subnational vaccination coverage of measles first-dose (MCV1) and estimate patterns of inequalities in impact, represented as deaths averted, across 45 countries in Africa. We also evaluate how much this impact would improve under more equitable vaccination coverage scenarios. Using coverage data for MCV1 from 2000-2019, we estimate the number of deaths averted at the first administrative level. We use the ratio of deaths averted per vaccination from two mathematical models to extrapolate the impact at a subnational level. Next, we calculate inequality for each country, measuring the spread of deaths averted across its regions, accounting for differences in population. Finally, using three more equitable vaccination coverage scenarios, we evaluate how much impact of MCV1 immunisation could improve by (1) assuming all regions in a country have at least national coverage, (2) assuming all regions have the observed maximum coverage; and (3) assuming all regions have at least 80% coverage. Our results show that progress in coverage and reducing inequality has slowed in the last decade in many African countries. Under the three scenarios, a significant number of additional deaths in children could be prevented each year; for example, under the observed maximum coverage scenario, global MCV1 coverage would improve from 76% to 90%, resulting in a further 363(95%CrI:299-482) deaths averted per 100,000 live births. This paper illustrates that estimates of the impact of MCV1 immunisation at a national level can mask subnational heterogeneity. We further show that a considerable number of deaths could be prevented by maximising equitable access in countries with high inequality when increasing the global coverage of MCV1 vaccination.
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Winter AK, Lambert B, Klein D, Klepac P, Papadopoulos T, Truelove S, Burgess C, Santos H, Knapp JK, Reef SE, Kayembe LK, Shendale S, Kretsinger K, Lessler J, Vynnycky E, McCarthy K, Ferrari M, Jit M. Feasibility of measles and rubella vaccination programmes for disease elimination: a modelling study. THE LANCET GLOBAL HEALTH 2022; 10:e1412-e1422. [PMID: 36113527 PMCID: PMC9557212 DOI: 10.1016/s2214-109x(22)00335-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 06/21/2022] [Accepted: 07/18/2022] [Indexed: 12/15/2022] Open
Abstract
Background Marked reductions in the incidence of measles and rubella have been observed since the widespread use of the measles and rubella vaccines. Although no global goal for measles eradication has been established, all six WHO regions have set measles elimination targets. However, a gap remains between current control levels and elimination targets, as shown by large measles outbreaks between 2017 and 2019. We aimed to model the potential for measles and rubella elimination globally to inform a WHO report to the 73rd World Health Assembly on the feasibility of measles and rubella eradication. Methods In this study, we modelled the probability of measles and rubella elimination between 2020 and 2100 under different vaccination scenarios in 93 countries of interest. We evaluated measles and rubella burden and elimination across two national transmission models each (Dynamic Measles Immunisation Calculation Engine [DynaMICE], Pennsylvania State University [PSU], Johns Hopkins University, and Public Health England models), and one subnational measles transmission model (Institute for Disease Modeling model). The vaccination scenarios included a so-called business as usual approach, which continues present vaccination coverage, and an intensified investment approach, which increases coverage into the future. The annual numbers of infections projected by each model, country, and vaccination scenario were used to explore if, when, and for how long the infections would be below a threshold for elimination. Findings The intensified investment scenario led to large reductions in measles and rubella incidence and burden. Rubella elimination is likely to be achievable in all countries and measles elimination is likely in some countries, but not all. The PSU and DynaMICE national measles models estimated that by 2050, the probability of elimination would exceed 75% in 14 (16%) and 36 (39%) of 93 modelled countries, respectively. The subnational model of measles transmission highlighted inequity in routine coverage as a likely driver of the continuance of endemic measles transmission in a subset of countries. Interpretation To reach regional elimination goals, it will be necessary to innovate vaccination strategies and technologies that increase spatial equity of routine vaccination, in addition to investing in existing surveillance and outbreak response programmes. Funding WHO, Gavi, the Vaccine Alliance, US Centers for Disease Control and Prevention, and the Bill & Melinda Gates Foundation.
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Toor J, Li X, Jit M, Trotter CL, Echeverria-Londono S, Hartner AM, Roth J, Portnoy A, Abbas K, Ferguson NM, Am Gaythorpe K. COVID-19 impact on routine immunisations for vaccine-preventable diseases: Projecting the effect of different routes to recovery. Vaccine 2022; 40:4142-4149. [PMID: 35672179 PMCID: PMC9148934 DOI: 10.1016/j.vaccine.2022.05.074] [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: 01/25/2022] [Revised: 05/13/2022] [Accepted: 05/24/2022] [Indexed: 11/23/2022]
Abstract
Over the past two decades, vaccination programmes for vaccine-preventable diseases (VPDs) have expanded across low- and middle-income countries (LMICs). However, the rise of COVID-19 resulted in global disruption to routine immunisation activities. Such disruptions could have a detrimental effect on public health, leading to more deaths from VPDs, particularly without mitigation efforts. Hence, as routine immunisation activities resume, it is important to estimate the effectiveness of different approaches for recovery. We apply an impact extrapolation method developed by the Vaccine Impact Modelling Consortium to estimate the impact of COVID-19-related disruptions with different recovery scenarios for ten VPDs across 112 LMICs. We focus on deaths averted due to routine immunisations occurring in the years 2020–2030 and investigate two recovery scenarios relative to a no-COVID-19 scenario. In the recovery scenarios, we assume a 10% COVID-19-related drop in routine immunisation coverage in the year 2020. We then linearly interpolate coverage to the year 2030 to investigate two routes to recovery, whereby the immunization agenda (IA2030) targets are reached by 2030 or fall short by 10%. We estimate that falling short of the IA2030 targets by 10% leads to 11.26% fewer fully vaccinated persons (FVPs) and 11.34% more deaths over the years 2020–2030 relative to the no-COVID-19 scenario, whereas, reaching the IA2030 targets reduces these proportions to 5% fewer FVPs and 5.22% more deaths. The impact of the disruption varies across the VPDs with diseases where coverage expands drastically in future years facing a smaller detrimental effect. Overall, our results show that drops in routine immunisation coverage could result in more deaths due to VPDs. As the impact of COVID-19-related disruptions is dependent on the vaccination coverage that is achieved over the coming years, the continued efforts of building up coverage and addressing gaps in immunity are vital in the road to recovery.
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Affiliation(s)
- Jaspreet Toor
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom.
| | - Xiang Li
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom
| | - Mark Jit
- London School of Hygiene and Tropical Medicine, London, United Kingdom; University of Hong Kong, Hong Kong Special Administrative Region, Hong Kong, China
| | | | - Susy Echeverria-Londono
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom
| | - Anna-Maria Hartner
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom
| | - Jeremy Roth
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom
| | - Allison Portnoy
- Center for Health Decision Science, Harvard T H Chan School of Public Health, Boston, United States
| | - Kaja Abbas
- London School of Hygiene and Tropical Medicine, London, United Kingdom
| | - Neil M Ferguson
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom
| | - Katy Am Gaythorpe
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, United Kingdom.
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Portnoy A, Hsieh YL, Abbas K, Klepac P, Santos H, Brenzel L, Jit M, Ferrari M. Differential health impact of intervention programs for time-varying disease risk: a measles vaccination modeling study. BMC Med 2022; 20:113. [PMID: 35260139 PMCID: PMC8904070 DOI: 10.1186/s12916-022-02242-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 01/06/2022] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Dynamic modeling is commonly used to evaluate direct and indirect effects of interventions on infectious disease incidence. The risk of secondary outcomes (e.g., death) attributable to infection may depend on the underlying disease incidence targeted by the intervention. Consequently, the impact of interventions (e.g., the difference in vaccination and no-vaccination scenarios) on secondary outcomes may not be proportional to the reduction in disease incidence. Here, we illustrate the estimation of the impact of vaccination on measles mortality, where case fatality ratios (CFRs) are a function of dynamically changing measles incidence. METHODS We used a previously published model of measles CFR that depends on incidence and vaccine coverage to illustrate the effects of (1) assuming higher CFR in "no-vaccination" scenarios, (2) time-varying CFRs over the past, and (3) time-varying CFRs in future projections on measles impact estimation. We used modeled CFRs in alternative scenarios to estimate measles deaths from 2000 to 2030 in 112 low- and middle-income countries using two models of measles transmission: Pennsylvania State University (PSU) and DynaMICE. We evaluated how different assumptions on future vaccine coverage, measles incidence, and CFR levels in "no-vaccination" scenarios affect the estimation of future deaths averted by measles vaccination. RESULTS Across 2000-2030, when CFRs are separately estimated for the "no-vaccination" scenario, the measles deaths averted estimated by PSU increased from 85.8% with constant CFRs to 86.8% with CFRs varying 2000-2018 and then held constant or 85.9% with CFRs varying across the entire time period and by DynaMICE changed from 92.0 to 92.4% or 91.9% in the same scenarios, respectively. By aligning both the "vaccination" and "no-vaccination" scenarios with time-variant measles CFR estimates, as opposed to assuming constant CFRs, the number of deaths averted in the vaccination scenarios was larger in historical years and lower in future years. CONCLUSIONS To assess the consequences of health interventions, impact estimates should consider the effect of "no-intervention" scenario assumptions on model parameters, such as measles CFR, in order to project estimated impact for alternative scenarios according to intervention strategies and investment decisions.
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Affiliation(s)
- Allison Portnoy
- Center for Health Decision Science, Harvard T.H. Chan School of Public Health, 718 Huntington Avenue 2nd Floor, Boston, MA, 02115, USA.
| | - Yuli Lily Hsieh
- Interfaculty Initiative in Health Policy, Harvard University, Cambridge, 02138, USA
| | - Kaja Abbas
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Petra Klepac
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Heather Santos
- Department of Biology, Pennsylvania State University, State College, 16801, USA
| | - Logan Brenzel
- Bill & Melinda Gates Foundation, Seattle, 98109, USA
| | - Mark Jit
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Matthew Ferrari
- Department of Biology, Pennsylvania State University, State College, 16801, USA
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Dong TQ, Wakefield J. Space-time smoothing models for subnational measles routine immunization coverage estimation with complex survey data. Ann Appl Stat 2021. [DOI: 10.1214/21-aoas1474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Tracy Qi Dong
- Department of Biostatistics, University of Washington
| | - Jon Wakefield
- Departments of Biostatistics and Statistics, University of Washington
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Fu H, Abbas K, Klepac P, van Zandvoort K, Tanvir H, Portnoy A, Jit M. Effect of evidence updates on key determinants of measles vaccination impact: a DynaMICE modelling study in ten high-burden countries. BMC Med 2021; 19:281. [PMID: 34784922 PMCID: PMC8594955 DOI: 10.1186/s12916-021-02157-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 10/07/2021] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Model-based estimates of measles burden and the impact of measles-containing vaccine (MCV) are crucial for global health priority setting. Recently, evidence from systematic reviews and database analyses have improved our understanding of key determinants of MCV impact. We explore how representations of these determinants affect model-based estimation of vaccination impact in ten countries with the highest measles burden. METHODS Using Dynamic Measles Immunisation Calculation Engine (DynaMICE), we modelled the effect of evidence updates for five determinants of MCV impact: case-fatality risk, contact patterns, age-dependent vaccine efficacy, the delivery of supplementary immunisation activities (SIAs) to zero-dose children, and the basic reproduction number. We assessed the incremental vaccination impact of the first (MCV1) and second (MCV2) doses of routine immunisation and SIAs, using metrics of total vaccine-averted cases, deaths, and disability-adjusted life years (DALYs) over 2000-2050. We also conducted a scenario capturing the effect of COVID-19 related disruptions on measles burden and vaccination impact. RESULTS Incorporated with the updated data sources, DynaMICE projected 253 million measles cases, 3.8 million deaths and 233 million DALYs incurred over 2000-2050 in the ten high-burden countries when MCV1, MCV2, and SIA doses were implemented. Compared to no vaccination, MCV1 contributed to 66% reduction in cumulative measles cases, while MCV2 and SIAs reduced this further to 90%. Among the updated determinants, shifting from fixed to linearly-varying vaccine efficacy by age and from static to time-varying case-fatality risks had the biggest effect on MCV impact. While varying the basic reproduction number showed a limited effect, updates on the other four determinants together resulted in an overall reduction of vaccination impact by 0.58%, 26.2%, and 26.7% for cases, deaths, and DALYs averted, respectively. COVID-19 related disruptions to measles vaccination are not likely to change the influence of these determinants on MCV impact, but may lead to a 3% increase in cases over 2000-2050. CONCLUSIONS Incorporating updated evidence particularly on vaccine efficacy and case-fatality risk reduces estimates of vaccination impact moderately, but its overall impact remains considerable. High MCV coverage through both routine immunisation and SIAs remains essential for achieving and maintaining low incidence in high measles burden settings.
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Affiliation(s)
- Han Fu
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
| | - Kaja Abbas
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.,Public Health Foundation of India, New Delhi, India.,International Vaccine Institute, Seoul, South Korea
| | - Petra Klepac
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.,Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Cambridge, UK
| | - Kevin van Zandvoort
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Hira Tanvir
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK
| | - Allison Portnoy
- Center for Health Decision Science, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Mark Jit
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.,Modelling and Economics Unit, Public Health England, London, UK.,School of Public Health, University of Hong Kong, Hong Kong, SAR, China
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Echeverria-Londono S, Li X, Toor J, de Villiers MJ, Nayagam S, Hallett TB, Abbas K, Jit M, Klepac P, Jean K, Garske T, Ferguson NM, Gaythorpe KAM. How can the public health impact of vaccination be estimated? BMC Public Health 2021; 21:2049. [PMID: 34753437 PMCID: PMC8577012 DOI: 10.1186/s12889-021-12040-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Accepted: 10/19/2021] [Indexed: 11/25/2022] Open
Abstract
Background Deaths due to vaccine preventable diseases cause a notable proportion of mortality worldwide. To quantify the importance of vaccination, it is necessary to estimate the burden averted through vaccination. The Vaccine Impact Modelling Consortium (VIMC) was established to estimate the health impact of vaccination. Methods We describe the methods implemented by the VIMC to estimate impact by calendar year, birth year and year of vaccination (YoV). The calendar and birth year methods estimate impact in a particular year and over the lifetime of a particular birth cohort, respectively. The YoV method estimates the impact of a particular year’s vaccination activities through the use of impact ratios which have no stratification and stratification by activity type and/or birth cohort. Furthermore, we detail an impact extrapolation (IE) method for use between coverage scenarios. We compare the methods, focusing on YoV for hepatitis B, measles and yellow fever. Results We find that the YoV methods estimate similar impact with routine vaccinations but have greater yearly variation when campaigns occur with the birth cohort stratification. The IE performs well for the YoV methods, providing a time-efficient mechanism for updates to impact estimates. Conclusions These methods provide a robust set of approaches to quantify vaccination impact; however it is vital that the area of impact estimation continues to develop in order to capture the full effect of immunisation.
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Affiliation(s)
- Susy Echeverria-Londono
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Xiang Li
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Jaspreet Toor
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Margaret J de Villiers
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Shevanthi Nayagam
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Timothy B Hallett
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Kaja Abbas
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Mark Jit
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Petra Klepac
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, WC1E 7HT, UK
| | - Kévin Jean
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK.,Laboratoire MESuRS, Conservatoire national des Arts et Métiers, Paris, France.,Unité PACRI, Institut Pasteur, Conservatoire national des Arts et Métiers, Paris, France
| | - Tini Garske
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Neil M Ferguson
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK
| | - Katy A M Gaythorpe
- MRC Centre for Global Infectious Disease Analysis, Jameel Institute, School of Public Health, Imperial College London, London, UK.
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12
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Toor J, Echeverria-Londono S, Li X, Abbas K, Carter ED, Clapham HE, Clark A, de Villiers MJ, Eilertson K, Ferrari M, Gamkrelidze I, Hallett TB, Hinsley WR, Hogan D, Huber JH, Jackson ML, Jean K, Jit M, Karachaliou A, Klepac P, Kraay A, Lessler J, Li X, Lopman BA, Mengistu T, Metcalf CJE, Moore SM, Nayagam S, Papadopoulos T, Perkins TA, Portnoy A, Razavi H, Razavi-Shearer D, Resch S, Sanderson C, Sweet S, Tam Y, Tanvir H, Tran Minh Q, Trotter CL, Truelove SA, Vynnycky E, Walker N, Winter A, Woodruff K, Ferguson NM, Gaythorpe KAM. Lives saved with vaccination for 10 pathogens across 112 countries in a pre-COVID-19 world. eLife 2021; 10:e67635. [PMID: 34253291 PMCID: PMC8277373 DOI: 10.7554/elife.67635] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 05/26/2021] [Indexed: 12/12/2022] Open
Abstract
Background Vaccination is one of the most effective public health interventions. We investigate the impact of vaccination activities for Haemophilus influenzae type b, hepatitis B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, rotavirus, rubella, Streptococcus pneumoniae, and yellow fever over the years 2000-2030 across 112 countries. Methods Twenty-one mathematical models estimated disease burden using standardised demographic and immunisation data. Impact was attributed to the year of vaccination through vaccine-activity-stratified impact ratios. Results We estimate 97 (95%CrI[80, 120]) million deaths would be averted due to vaccination activities over 2000-2030, with 50 (95%CrI[41, 62]) million deaths averted by activities between 2000 and 2019. For children under-5 born between 2000 and 2030, we estimate 52 (95%CrI[41, 69]) million more deaths would occur over their lifetimes without vaccination against these diseases. Conclusions This study represents the largest assessment of vaccine impact before COVID-19-related disruptions and provides motivation for sustaining and improving global vaccination coverage in the future. Funding VIMC is jointly funded by Gavi, the Vaccine Alliance, and the Bill and Melinda Gates Foundation (BMGF) (BMGF grant number: OPP1157270 / INV-009125). Funding from Gavi is channelled via VIMC to the Consortium's modelling groups (VIMC-funded institutions represented in this paper: Imperial College London, London School of Hygiene and Tropical Medicine, Oxford University Clinical Research Unit, Public Health England, Johns Hopkins University, The Pennsylvania State University, Center for Disease Analysis Foundation, Kaiser Permanente Washington, University of Cambridge, University of Notre Dame, Harvard University, Conservatoire National des Arts et Métiers, Emory University, National University of Singapore). Funding from BMGF was used for salaries of the Consortium secretariat (authors represented here: TBH, MJ, XL, SE-L, JT, KW, NMF, KAMG); and channelled via VIMC for travel and subsistence costs of all Consortium members (all authors). We also acknowledge funding from the UK Medical Research Council and Department for International Development, which supported aspects of VIMC's work (MRC grant number: MR/R015600/1).JHH acknowledges funding from National Science Foundation Graduate Research Fellowship; Richard and Peggy Notebaert Premier Fellowship from the University of Notre Dame. BAL acknowledges funding from NIH/NIGMS (grant number R01 GM124280) and NIH/NIAID (grant number R01 AI112970). The Lives Saved Tool (LiST) receives funding support from the Bill and Melinda Gates Foundation.This paper was compiled by all coauthors, including two coauthors from Gavi. Other funders had no role in study design, data collection, data analysis, data interpretation, or writing of the report. All authors had full access to all the data in the study and had final responsibility for the decision to submit for publication.
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Affiliation(s)
- Jaspreet Toor
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Susy Echeverria-Londono
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Xiang Li
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Kaja Abbas
- London School of Hygiene and Tropical MedicineLondonUnited Kingdom
| | - Emily D Carter
- Bloomberg School of Public Health, Johns Hopkins UniversityBaltimoreUnited States
| | - Hannah E Clapham
- Saw Swee Hock School of Public Health, National University of Singapore, Singapore; Oxford University Clinical Research Unit, Vietnam; Nuffield Department of Medicine, Oxford UniversityOxfordUnited Kingdom
| | - Andrew Clark
- London School of Hygiene and Tropical MedicineLondonUnited Kingdom
| | - Margaret J de Villiers
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | | | | | | | - Timothy B Hallett
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Wes R Hinsley
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | | | - John H Huber
- Department of Biological Sciences, University of Notre DameNotre DameUnited States
| | | | - Kevin Jean
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
- Laboratoire MESuRS and Unite PACRI, Institut Pasteur, Conservatoire National des Arts et MetiersParisFrance
| | - Mark Jit
- London School of Hygiene and Tropical MedicineLondonUnited Kingdom
- University of Hong Kong, Hong Kong Special Administrative RegionHong KongChina
| | | | - Petra Klepac
- London School of Hygiene and Tropical MedicineLondonUnited Kingdom
| | - Alicia Kraay
- Rollins School of Public Health, Emory UniversityAtlantaUnited States
| | - Justin Lessler
- Bloomberg School of Public Health, Johns Hopkins UniversityBaltimoreUnited States
| | - Xi Li
- IndependentAtlantaUnited States
| | - Benjamin A Lopman
- Rollins School of Public Health, Emory UniversityAtlantaUnited States
| | | | | | - Sean M Moore
- Department of Biological Sciences, University of Notre DameNotre DameUnited States
| | - Shevanthi Nayagam
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
- Section of Hepatology and Gastroenterology, Department of Metabolism, Digestion and Reproduction, Imperial College LondonLondonUnited Kingdom
| | - Timos Papadopoulos
- Public Health EnglandLondonUnited Kingdom
- University of SouthamptonSouthamptonUnited Kingdom
| | - T Alex Perkins
- Department of Biological Sciences, University of Notre DameNotre DameUnited States
| | - Allison Portnoy
- Center for Health Decision Science, Harvard T H Chan School of Public Health, Harvard UniversityCambridgeUnited States
| | - Homie Razavi
- Center for Disease Analysis FoundationLafayetteUnited States
| | | | - Stephen Resch
- Center for Health Decision Science, Harvard T H Chan School of Public Health, Harvard UniversityCambridgeUnited States
| | - Colin Sanderson
- London School of Hygiene and Tropical MedicineLondonUnited Kingdom
| | - Steven Sweet
- Center for Health Decision Science, Harvard T H Chan School of Public Health, Harvard UniversityCambridgeUnited States
| | - Yvonne Tam
- Bloomberg School of Public Health, Johns Hopkins UniversityBaltimoreUnited States
| | - Hira Tanvir
- London School of Hygiene and Tropical MedicineLondonUnited Kingdom
| | - Quan Tran Minh
- Department of Biological Sciences, University of Notre DameNotre DameUnited States
| | | | - Shaun A Truelove
- Bloomberg School of Public Health, Johns Hopkins UniversityBaltimoreUnited States
| | | | - Neff Walker
- Bloomberg School of Public Health, Johns Hopkins UniversityBaltimoreUnited States
| | - Amy Winter
- Bloomberg School of Public Health, Johns Hopkins UniversityBaltimoreUnited States
| | - Kim Woodruff
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Neil M Ferguson
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Katy AM Gaythorpe
- MRC Centre for Global Infectious Disease Analysis; and the Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
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13
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Gaythorpe KAM, Abbas K, Huber J, Karachaliou A, Thakkar N, Woodruff K, Li X, Echeverria-Londono S, Ferrari M, Jackson ML, McCarthy K, Perkins TA, Trotter C, Jit M. Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries. eLife 2021; 10:e67023. [PMID: 34165077 PMCID: PMC8263060 DOI: 10.7554/elife.67023] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Accepted: 06/23/2021] [Indexed: 12/30/2022] Open
Abstract
Background Childhood immunisation services have been disrupted by the COVID-19 pandemic. WHO recommends considering outbreak risk using epidemiological criteria when deciding whether to conduct preventive vaccination campaigns during the pandemic. Methods We used two to three models per infection to estimate the health impact of 50% reduced routine vaccination coverage in 2020 and delay of campaign vaccination from 2020 to 2021 for measles vaccination in Bangladesh, Chad, Ethiopia, Kenya, Nigeria, and South Sudan, for meningococcal A vaccination in Burkina Faso, Chad, Niger, and Nigeria, and for yellow fever vaccination in the Democratic Republic of Congo, Ghana, and Nigeria. Our counterfactual comparative scenario was sustaining immunisation services at coverage projections made prior to COVID-19 (i.e. without any disruption). Results Reduced routine vaccination coverage in 2020 without catch-up vaccination may lead to an increase in measles and yellow fever disease burden in the modelled countries. Delaying planned campaigns in Ethiopia and Nigeria by a year may significantly increase the risk of measles outbreaks (both countries did complete their supplementary immunisation activities (SIAs) planned for 2020). For yellow fever vaccination, delay in campaigns leads to a potential disease burden rise of >1 death per 100,000 people per year until the campaigns are implemented. For meningococcal A vaccination, short-term disruptions in 2020 are unlikely to have a significant impact due to the persistence of direct and indirect benefits from past introductory campaigns of the 1- to 29-year-old population, bolstered by inclusion of the vaccine into the routine immunisation schedule accompanied by further catch-up campaigns. Conclusions The impact of COVID-19-related disruption to vaccination programs varies between infections and countries. Planning and implementation of campaigns should consider country and infection-specific epidemiological factors and local immunity gaps worsened by the COVID-19 pandemic when prioritising vaccines and strategies for catch-up vaccination. Funding Bill and Melinda Gates Foundation and Gavi, the Vaccine Alliance.
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Affiliation(s)
- Katy AM Gaythorpe
- MRC Centre for Global Infectious Disease Analysis, Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Kaja Abbas
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical MedicineLondonUnited Kingdom
| | - John Huber
- Department of Biological Sciences, University of Notre DameSouth BendUnited States
| | | | - Niket Thakkar
- Institute for Disease Modeling, Bill & Melinda Gates FoundationSeattleUnited States
| | - Kim Woodruff
- MRC Centre for Global Infectious Disease Analysis, Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Xiang Li
- MRC Centre for Global Infectious Disease Analysis, Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | - Susy Echeverria-Londono
- MRC Centre for Global Infectious Disease Analysis, Abdul Latif Jameel Institute for Disease and Emergency Analytics (J-IDEA), School of Public Health, Imperial College LondonLondonUnited Kingdom
| | | | | | - Kevin McCarthy
- Institute for Disease Modeling, Bill & Melinda Gates FoundationSeattleUnited States
| | - T Alex Perkins
- Department of Biological Sciences, University of Notre DameSouth BendUnited States
| | - Caroline Trotter
- Department of Veterinary Medicine, University of CambridgeCambridgeUnited Kingdom
| | - Mark Jit
- Centre for Mathematical Modelling of Infectious Diseases, London School of Hygiene & Tropical MedicineLondonUnited Kingdom
- School of Public Health, University of Hong KongHong Kong SARChina
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Moss WJ, Shendale S, Lindstrand A, O'Brien KL, Turner N, Goodman T, Kretsinger K. Feasibility assessment of measles and rubella eradication. Vaccine 2021; 39:3544-3559. [PMID: 34045102 DOI: 10.1016/j.vaccine.2021.04.027] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 04/14/2021] [Indexed: 12/28/2022]
Abstract
This report addresses the epidemiological aspects and feasibility of measles and rubella eradication and the potential resource requirements in response to the request of the Director-General at the Seventieth World Health Assembly held on May 31, 2017. A guiding principle is that the path toward measles and rubella eradication should serve to strengthen primary health care, promote universal health coverage, and be a pathfinder for new vision and strategy for immunization over the next decade as laid out in the Immunization Agenda 2030. Specifically, this report: 1) highlights the importance of measles and rubella as global health priorities; 2) reviews the current global measles and rubella situation; 3) summarizes prior assessments of the feasibility of measles and rubella eradication; 4) assesses the progress and challenges in achieving regional measles and rubella elimination; 5) assesses additional considerations for measles and rubella eradication, including the results of modelling and economic analyses; 6) assesses the implications of establishing a measles and rubella eradication goal and the process for setting an eradication target date; 7) proposes a framework for determining preconditions for setting a target date for measles and rubella eradication and how these preconditions should be understood and used; and 8) concludes with recommendations endorsed by SAGE.
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Affiliation(s)
- William J Moss
- International Vaccine Access Center, Departments of Epidemiology and International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.
| | - Stephanie Shendale
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Ann Lindstrand
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Katherine L O'Brien
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Nikki Turner
- Division of General Practice and Primary Health Care, University of Auckland, Auckland, New Zealand
| | - Tracey Goodman
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
| | - Katrina Kretsinger
- Department of Immunization, Vaccines and Biologicals, World Health Organization, Geneva, Switzerland
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Menkir TF, Jbaily A, Verguet S. Incorporating equity in infectious disease modeling: Case study of a distributional impact framework for measles transmission. Vaccine 2021; 39:2894-2900. [PMID: 33863575 PMCID: PMC8117973 DOI: 10.1016/j.vaccine.2021.03.023] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 02/22/2021] [Accepted: 03/04/2021] [Indexed: 11/21/2022]
Abstract
INTRODUCTION Deterministic compartmental models of infectious diseases like measles typically reflect biological heterogeneities in the risk of infection and severity to characterize transmission dynamics. Given the known association of socioeconomic status and increased vulnerability to infection and mortality, it is also critical that such models further incorporate social heterogeneities. METHODS Here, we aimed to explore the influence of integrating income-associated differences in parameters of traditional dynamic transmission models. We developed a measles SIR model, in which the Susceptible, Infected and Recovered classes were stratified by income quintile, with income-specific transmission rates, disease-induced mortality rates, and vaccination coverage levels. We further provided a stylized illustration with secondary data from Ethiopia, where we examined various scenarios demonstrating differences in transmission patterns by income and in distributional vaccination coverage, and quantified impacts on disparities in measles mortality. RESULTS The income-stratified SIR model exhibited similar dynamics to that of the traditional SIR model, with amplified outbreak peaks and measles mortality among the poorest income group. All vaccination coverage strategies were found to substantially curb the overall number of measles deaths, yet most considerably for the poorest, with select strategies yielding clear reductions in measles mortality disparities. DISCUSSION The incorporation of income-specific differences can reveal distinct outbreak patterns across income groups and important differences in the subsequent effects of preventative interventions like vaccination. Our case study highlights the need to extend traditional modeling frameworks (e.g. SIR models) to be stratified by socioeconomic factors like income and to consider ensuing income-associated differences in disease-related morbidity and mortality. In so doing, we build on existing tools and characterize ongoing challenges in achieving health equity.
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Affiliation(s)
- Tigist Ferede Menkir
- Center for Communicable Disease Dynamics, Department of Epidemiology, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Abdulrahman Jbaily
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA
| | - Stéphane Verguet
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, Harvard University, Boston, MA, USA.
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Hamisu M, Dieng B, Taiwo L, Jean Baptiste AE, Bawa S, Wagai J, Ibizugbe S, Braka F, Nsubuga P, Shuaib F, Oteri J. Microplanning verification and 2017/2018 measles vaccination campaign in Nigeria: Lessons learnt. Vaccine 2021; 39 Suppl 3:C46-C53. [PMID: 33892983 DOI: 10.1016/j.vaccine.2021.04.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 03/29/2021] [Accepted: 04/06/2021] [Indexed: 11/15/2022]
Abstract
INTRODUCTION The measles supplemental immunisation activity is an effective strategy that improves vaccination coverage and reduces measles-related morbidity and mortality. However, the lack of compliance with microplanning processes, contributes to improper estimation of resources needed for a good SIA in Nigeria. We described the microplanning verification process for 2017/2018 measles vaccination campaign and highlighted the contribution of selected variables to the output of the microplan. METHODS We conducted microplanning verification in 2 phases. In Phase 1, we verified at least 30% of randomly selected microplans to assess compliance with the steps and processes of developing good microplans. In Phase 2 we conducted desk review of the entire states micoplans and verified some selected variables at the ward level to corroborate the findings of the microplans. We collected data using open data kit and verification checklist. We conducted data analysis using SPSS and Microsoft Excel version 2016. RESULTS All states in Nigeria verified their wards' microplans, 21 states (57%) verified more than 30% ,16 states (43%) verified less than 30%, Kebbi State verified the lowest (5.3%). Over 90% of microplans verified complied with the microplanning processes. We observed that overall, there was no significant difference in the number of target population, vaccination teams and qualified vaccinators after the verification process. CONCLUSION The microplans for 2017/2018 measles vaccination campaign were developed according to the required procesesses, the target population, vaccination teams and qualified vaccinators were physically and realistically estimated. Adherence to microplanning processes is critical to the success of immunization programs.
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Affiliation(s)
- Maimuna Hamisu
- National Primary Health Care Development Agency, Abuja, Nigeria
| | - Boubacar Dieng
- Technical Assistance Consultant, Global Alliance for Vaccines and Immunizations
| | - Lydia Taiwo
- Nigeria Field Epidemiology & Laboratory Training Program (NFELTP), Abuja, Nigeria
| | | | - Samuel Bawa
- World Health Organization, Country Office, Abuja, Nigeria
| | - John Wagai
- World Health Organization, Country Office, Abuja, Nigeria
| | | | - Fiona Braka
- World Health Organization, Country Office, Abuja, Nigeria
| | | | - Faisal Shuaib
- National Primary Health Care Development Agency, Abuja, Nigeria
| | - Joseph Oteri
- National Primary Health Care Development Agency, Abuja, Nigeria
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Xue Y, Ruan X, Xiao Y. Measles dynamics on network models with optimal control strategies. ADVANCES IN DIFFERENCE EQUATIONS 2021; 2021:138. [PMID: 33679964 PMCID: PMC7910804 DOI: 10.1186/s13662-021-03306-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Accepted: 02/15/2021] [Indexed: 06/05/2023]
Abstract
To investigate the influences of heterogeneity and waning immunity on measles transmission, we formulate a network model with periodic transmission rate, and theoretically examine the threshold dynamics. We numerically find that the waning of immunity can lead to an increase in the basic reproduction number R 0 and the density of infected individuals. Moreover, there exists a critical level for average degree above which R 0 increases quicker in the scale-free network than in the random network. To design the effective control strategies for the subpopulations with different activities, we examine the optimal control problem of the heterogeneous model. Numerical studies suggest us no matter what the network is, we should implement control measures as soon as possible once the outbreak takes off, and particularly, the subpopulation with high connectivity should require high intensity of interventions. However, with delayed initiation of controls, relatively strong control measures should be given to groups with medium degrees. Furthermore, the allocation of costs (or resources) should coincide with their contact patterns.
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Affiliation(s)
- Yuyi Xue
- School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, P.R. China
| | - Xiaoe Ruan
- School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, P.R. China
| | - Yanni Xiao
- School of Mathematics and Statistics, Xi’an Jiaotong University, Xi’an, P.R. China
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Cutts FT, Ferrari MJ, Krause LK, Tatem AJ, Mosser JF. Vaccination strategies for measles control and elimination: time to strengthen local initiatives. BMC Med 2021; 19:2. [PMID: 33397366 PMCID: PMC7781821 DOI: 10.1186/s12916-020-01843-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Accepted: 11/05/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Through a combination of strong routine immunization (RI), strategic supplemental immunization activities (SIA) and robust surveillance, numerous countries have been able to approach or achieve measles elimination. The fragility of these achievements has been shown, however, by the resurgence of measles since 2016. We describe trends in routine measles vaccine coverage at national and district level, SIA performance and demographic changes in the three regions with the highest measles burden. FINDINGS WHO-UNICEF estimates of immunization coverage show that global coverage of the first dose of measles vaccine has stabilized at 85% from 2015 to 19. In 2000, 17 countries in the WHO African and Eastern Mediterranean regions had measles vaccine coverage below 50%, and although all increased coverage by 2019, at a median of 60%, it remained far below levels needed for elimination. Geospatial estimates show many low coverage districts across Africa and much of the Eastern Mediterranean and southeast Asian regions. A large proportion of children unvaccinated for MCV live in conflict-affected areas with remote rural areas and some urban areas also at risk. Countries with low RI coverage use SIAs frequently, yet the ideal timing and target age range for SIAs vary within countries, and the impact of SIAs has often been mitigated by delays or disruptions. SIAs have not been sufficient to achieve or sustain measles elimination in the countries with weakest routine systems. Demographic changes also affect measles transmission, and their variation between and within countries should be incorporated into strategic planning. CONCLUSIONS Rebuilding services after the COVID-19 pandemic provides a need and an opportunity to increase community engagement in planning and monitoring services. A broader suite of interventions is needed beyond SIAs. Improved methods for tracking coverage at the individual and community level are needed together with enhanced surveillance. Decision-making needs to be decentralized to develop locally-driven, sustainable strategies for measles control and elimination.
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Affiliation(s)
- F T Cutts
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
| | - M J Ferrari
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA
| | - L K Krause
- Vaccine Delivery, Global Development, The Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - A J Tatem
- WorldPop, Department of Geography and Environmental Science, University of Southampton, Highfield, Southampton, SO17 1BJ, UK
| | - J F Mosser
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, 98121, USA
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19
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Nigus M, Zelalem M, Abraham K, Shiferaw A, Admassu M, Masresha B. Implementing nationwide measles supplemental immunization activities in Ethiopia in the context of COVID-19: process and lessons learnt. Pan Afr Med J 2020; 37:36. [PMID: 33456660 PMCID: PMC7796832 DOI: 10.11604/pamj.supp.2020.37.36.26614] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 11/13/2020] [Indexed: 11/11/2022] Open
Abstract
The COVID-19 pandemic has disrupted immunization activities in many countries, causing declines in the delivery of routine doses of antigens, and the postponement of scheduled supplemental immunization activities (SIAs). Following the declaration of the pandemic, Ethiopia postponed nationwide follow-up measles preventive vaccination campaign which was scheduled for April 2020. The disruptions to routine services and the postponement of the SIAs increased the risk for measles outbreaks. The national authorities, in consultation with the secretariat of the National COVID-19 Pandemic Prevention and Control Ministerial Coordination Committee, subnational level authorities, technical partner agencies and stakeholders, reviewed the risks for measles outbreaks and decided to implement the nationwide measles SIAs, with strict implementation of COVID prevention measures. The revised micro-plans accommodated the additional human resource and logistics needs for COVID prevention, for which partner resources were mobilized to fill the gaps. The key SIAs preparatory and implementation activities including training, logistics, social mobilization, service delivery and supervision were modified to take into consideration the COVID context. Infection prevention and control supplies were procured and distributed as a package with the bundled vaccines and other supplies. The SIAs were completed in July 2020 and reached 102.8% administrative coverage nationwide, with 78% of the 1123 woredas attaining the target of 95% coverage. The strong commitment of the leadership, the coordination role of the national and regional COVID prevention and control taskforces, the engagement of community leaders, the use of multi-channel communication, the timely availability of additional resources and modification of the service delivery approaches contributed to the success of the SIAs.
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Affiliation(s)
- Mulat Nigus
- Federal Ministry of Health, Addis Ababa, Ethiopia
| | | | | | - Amsalu Shiferaw
- United Nations Children's Fund (UNICEF), Addis Ababa, Ethiopia
| | | | - Balcha Masresha
- World Health Organization, Regional Office for Africa, Brazzaville, Congo
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20
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Nigus M, Zelalem M, Abraham K, Shiferaw A, Admassu M, Masresha B. Implementing nationwide measles supplemental immunization activities in Ethiopia in the context of COVID-19: process and lessons learnt. Pan Afr Med J 2020. [PMID: 33456660 PMCID: PMC7796832 DOI: 10.11604/pamj.supp.2020.37.1.26614] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The COVID-19 pandemic has disrupted immunization activities in many countries, causing declines in the delivery of routine doses of antigens, and the postponement of scheduled supplemental immunization activities (SIAs). Following the declaration of the pandemic, Ethiopia postponed nationwide follow-up measles preventive vaccination campaign which was scheduled for April 2020. The disruptions to routine services and the postponement of the SIAs increased the risk for measles outbreaks. The national authorities, in consultation with the secretariat of the National COVID-19 Pandemic Prevention and Control Ministerial Coordination Committee, subnational level authorities, technical partner agencies and stakeholders, reviewed the risks for measles outbreaks and decided to implement the nationwide measles SIAs, with strict implementation of COVID prevention measures. The revised micro-plans accommodated the additional human resource and logistics needs for COVID prevention, for which partner resources were mobilized to fill the gaps. The key SIAs preparatory and implementation activities including training, logistics, social mobilization, service delivery and supervision were modified to take into consideration the COVID context. Infection prevention and control supplies were procured and distributed as a package with the bundled vaccines and other supplies. The SIAs were completed in July 2020 and reached 102.8% administrative coverage nationwide, with 78% of the 1123 woredas attaining the target of 95% coverage. The strong commitment of the leadership, the coordination role of the national and regional COVID prevention and control taskforces, the engagement of community leaders, the use of multi-channel communication, the timely availability of additional resources and modification of the service delivery approaches contributed to the success of the SIAs.
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Affiliation(s)
- Mulat Nigus
- Federal Ministry of Health, Addis Ababa, Ethiopia
| | | | | | - Amsalu Shiferaw
- United Nations Children's Fund (UNICEF), Addis Ababa, Ethiopia
| | | | - Balcha Masresha
- World Health Organization, Regional Office for Africa, Brazzaville, Congo
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21
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Changes in Measles Seroprevalence in China After the Launch of Two Provincial Supplementary Immunization Activities During 2009 to 2013. Pediatr Infect Dis J 2020; 39:867-871. [PMID: 32404783 DOI: 10.1097/inf.0000000000002731] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Supplementary immunization activities (SIAs) have been demonstrated being effective in reducing measles incidence within a short period of time in China, but the effects are short-lived if there is no follow-up SIA with high routine immunization coverage. OBJECTIVES To assess the change in measles seroprevalence from 2009 to 2013 after the launch of 2 large-scale SIAs within the period. METHODS Three population-based cross-sectional serologic surveys of measles antibodies were conducted in 2009, 2011 and 2013 in Zhejiang, a province in eastern China, with serologic samples collected from 1541, 896 and 1474 subjects, respectively. The serum levels of immunoglobulin G antibodies were measured by enzyme-linked immunosorbent assay. RESULTS We found that the seropositivity rate among infants 0-7 months of age, a group having no vaccination benefit, was below 80% throughout the study period. In addition, the seropositivity rate among adults 30-49 years of age decreased significantly from 96.0% (95% confidence interval: 93.7%-98.3%) in 2011 to 88.5% (95% confidence interval: 84.3%-92.8%) in 2013. CONCLUSION We showed that large-scale SIAs were effective, but their effects were not long lasting. Given the drop in seropositivity among adults, their susceptibility should be carefully monitored. While older individuals could benefit from the immunization activities, children who were too young to be vaccinated still have a weak seropositivity profile and the optimal age for the administration of the first dose of vaccine should be reconsidered.
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22
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Urabe CT, Tanaka G, Oshima T, Maruyama A, Misaki T, Okabe N, Aihara K. Comparing catch-up vaccination programs based on analysis of 2012-13 rubella outbreak in Kawasaki City, Japan. PLoS One 2020; 15:e0237312. [PMID: 32797060 PMCID: PMC7428070 DOI: 10.1371/journal.pone.0237312] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2019] [Accepted: 07/26/2020] [Indexed: 11/28/2022] Open
Abstract
During the 2012–13 rubella outbreak in Japan, local governments implemented subsidy programs for catch-up vaccination to mitigate the rubella outbreak and prevent congenital rubella syndrome (CRS). In most local governments, to prevent CRS, eligible persons of the subsidy program were women who were planning to have a child and men who were partners of pregnant women. On the other hand, in Kawasaki City, unimmunized men aged 23–39 years were additionally included in the eligible persons, because they were included in an unimmunized men group resulting from the historical transition of the national routine vaccination in Japan. The number of rubella cases in the city decreased earlier than that in the whole Japan. First, in order to estimate the effect of the catch-up vaccination campaign in Kawasaki City on the epidemic outcome, we performed numerical simulations with a Susceptible-Vaccinated-Exposed-Infectious-Recovered (SVEIR) model incorporating real data. The result indicated that the catch-up vaccination campaign showed a beneficial impact on the early decay of the rubella cases. Second, we numerically compared several different implementation strategies of catch-up vaccinations under a fixed amount of total vaccinations. As a result, we found that early and intensive vaccinations are vital for significant reduction in the number of rubella cases and CRS occurrences. Our study suggests that mathematical models with epidemiological and social data can contribute to identifying the most effective vaccination strategy.
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Affiliation(s)
- Chiyori T. Urabe
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
- * E-mail:
| | - Gouhei Tanaka
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
- Graduate School of Engineering, The University of Tokyo, Tokyo, Japan
| | | | - Aya Maruyama
- Kawasaki City Institute for Public Health, Kawasaki, Japan
| | - Takako Misaki
- Kawasaki City Institute for Public Health, Kawasaki, Japan
| | - Nobuhiko Okabe
- Kawasaki City Institute for Public Health, Kawasaki, Japan
| | - Kazuyuki Aihara
- Institute of Industrial Science, The University of Tokyo, Tokyo, Japan
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23
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Phillips B, Anand M, Bauch CT. Spatial early warning signals of social and epidemiological tipping points in a coupled behaviour-disease network. Sci Rep 2020; 10:7611. [PMID: 32376908 PMCID: PMC7203335 DOI: 10.1038/s41598-020-63849-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 04/06/2020] [Indexed: 01/12/2023] Open
Abstract
The resurgence of infectious diseases due to vaccine refusal has highlighted the role of interactions between disease dynamics and the spread of vaccine opinion on social networks. Shifts between disease elimination and outbreak regimes often occur through tipping points. It is known that tipping points can be predicted by early warning signals (EWS) based on characteristic dynamics near the critical transition, but the study of EWS in coupled behaviour-disease networks has received little attention. Here, we test several EWS indicators measuring spatial coherence and autocorrelation for their ability to predict a critical transition corresponding to disease outbreaks and vaccine refusal in a multiplex network model. The model couples paediatric infectious disease spread through a contact network to binary opinion dynamics of vaccine opinion on a social network. Through change point detection, we find that mutual information and join count indicators provided the best EWS. We also show the paediatric infectious disease natural history generates a discrepancy between population-level vaccine opinions and vaccine immunity status, such that transitions in the social network may occur before epidemiological transitions. These results suggest that monitoring social media for EWS of paediatric infectious disease outbreaks using these spatial indicators could be successful.
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Affiliation(s)
- Brendon Phillips
- University of Waterloo, Department of Mathematics, Waterloo, N2L 3G1, Canada.
| | - Madhur Anand
- University of Guelph, School of Environmental Sciences, Guelph, N1G 2W1, Canada
| | - Chris T Bauch
- University of Waterloo, Department of Mathematics, Waterloo, N2L 3G1, Canada
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24
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Fakhruddin M, Suandi D, Sumiati S, Fahlena H, Nuraini N, Soewono E. Investigation of a measles transmission with vaccination: a case study in Jakarta, Indonesia. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2020; 17:2998-3018. [PMID: 32987513 DOI: 10.3934/mbe.2020170] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Measles is a contagious disease caused by the measles virus of genus Morbillivirus, which has been spreading in many affected regions. This infection is characterized by the appearance of rashes all over the body and potentially cause serious complications, especially among infants and children. Before measles immunization was promoted, it is one of the endemic diseases that caused the most fatalities each year in the world. This paper aims to analyze and to investigate measles transmission in Jakarta via an SIHR epidemic model involving vaccination from January to December 2017. Jakarta Health Office collected the observed data of measles incidence. We then derived the basic reproduction number as a threshold of disease transmission and obtained the local as well as global stability of the equilibria under certain conditions. The unobserved parameters and initial conditions were estimated by minimizing errors between data and numerical results. Furthermore, a stochastic model was developed to capture the data and to accommodate the randomness of the transmission. Sensitivity analysis was also performed to analyze and to identify the parameters which give significant contributions to the spread of the virus. We then obtained simulations of vaccine level coverage. The data is shown within a 95% confidence interval of the stochastic solutions, and the average of the stochastic solutions is relatively close to the solution of the deterministic model. The most sensitive parameter in the infected compartment is the hospitalized rate, which can be considered to be one of the essential factors to reduce the number of cases for policymakers. We hence proposed a control strategy which is providing treatment accesses easier for infected individuals is better than vaccinating when an outbreak occurs.
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Affiliation(s)
- Muhammad Fakhruddin
- Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia
| | - Dani Suandi
- Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia
| | | | - Hilda Fahlena
- Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia
| | - Nuning Nuraini
- Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia
| | - Edy Soewono
- Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Bandung 40132, Indonesia
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25
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Koniushevska AA, Parkhomenko TA, Sharunova MV, Kazantsev AB, Yakovenko DV. Epidemiology and features of the measles course in children during the outbreak of 2018–2019 in the city of Mariupol. REGULATORY MECHANISMS IN BIOSYSTEMS 2020. [DOI: 10.15421/022010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
In 2017, Ukraine ranked in the top three among European countries in terms of measles incidence, and ranked first in measles growth in 2018. High morbidity, mortality and development of complications make the problem of knowing features of the measles clinical course, timely diagnosis and active prevention highly relevant. The purpose of the research is to study the dynamics of the incidence and clinical features of measles in children during the outbreak of 2018–2019 in the city of Mariupol, Donetsk region. A peculiarity of the measles outbreak in 2018–2019 in Mariupol is prevalence of the disease in preschool children (60.4%), including 30.2% – those under one year of age; low vaccination rate: 52.3% of children unvaccinated; only 22.2% of children were vaccinated twice, according to the schedule. In all age groups, a moderately severe measles course prevailed (69.8%). The clinical course of measles in preschool and school age children had definitive features. Thus, Belsky–Filatov–Koplik spots were observed three times more frequently in preschool children than in schoolchildren (63.9% and 23.3%, respectively). Abdominal pain and diarrhea were only observed in children under 6 years of age (30.2%). Skin pigmentation was absent in children under one year of age and was detected in preschool and school-age children (69.8%). Skin sloughing was only observed in schoolchildren (10.4%). Severe disease course occurred in patients of all ages (29.3%), but children aged under one year and preschool children with severe disease were two times more numerous than those of the school age. Among the observed complications, the vast majority were associated with the respiratory organs: pneumonia (38.3%), subcutaneous emphysema (1.7%), bronchitis (53.2%), laryngitis (3.3%), otitis media (5%). No fatalities were observed. The city should form a commitment to immunization, restore public trust in vaccination, using all forms and means of information, and develop a program to implement the vaccination schedule into practice.
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Cutts FT, Dansereau E, Ferrari MJ, Hanson M, McCarthy KA, Metcalf CJE, Takahashi S, Tatem AJ, Thakkar N, Truelove S, Utazi E, Wesolowski A, Winter AK. Using models to shape measles control and elimination strategies in low- and middle-income countries: A review of recent applications. Vaccine 2020; 38:979-992. [PMID: 31787412 PMCID: PMC6996156 DOI: 10.1016/j.vaccine.2019.11.020] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Revised: 11/07/2019] [Accepted: 11/08/2019] [Indexed: 01/30/2023]
Abstract
After many decades of vaccination, measles epidemiology varies greatly between and within countries. National immunization programs are therefore encouraged to conduct regular situation analyses and to leverage models to adapt interventions to local needs. Here, we review applications of models to develop locally tailored interventions to support control and elimination efforts. In general, statistical and semi-mechanistic transmission models can be used to synthesize information from vaccination coverage, measles incidence, demographic, and/or serological data, offering a means to estimate the spatial and age-specific distribution of measles susceptibility. These estimates complete the picture provided by vaccination coverage alone, by accounting for natural immunity. Dynamic transmission models can then be used to evaluate the relative impact of candidate interventions for measles control and elimination and the expected future epidemiology. In most countries, models predict substantial numbers of susceptible individuals outside the age range of routine vaccination, which affects outbreak risk and necessitates additional intervention to achieve elimination. More effective use of models to inform both vaccination program planning and evaluation requires the development of training to enhance broader understanding of models and where feasible, building capacity for modelling in-country, pipelines for rapid evaluation of model predictions using surveillance data, and clear protocols for incorporating model results into decision-making.
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Affiliation(s)
- F T Cutts
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK.
| | - E Dansereau
- Vaccine Delivery, Global Development, The Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - M J Ferrari
- Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, PA, USA
| | - M Hanson
- Vaccine Delivery, Global Development, The Bill & Melinda Gates Foundation, Seattle, WA, USA
| | - K A McCarthy
- Institute for Disease Modeling, 3150 139th Ave SE, Bellevue, WA 98005, USA
| | - C J E Metcalf
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
| | - S Takahashi
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA; Department of Medicine, University of California San Francisco, San Francisco, CA 94143, USA
| | - A J Tatem
- WorldPop, Department of Geography and Environmental Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - N Thakkar
- Institute for Disease Modeling, 3150 139th Ave SE, Bellevue, WA 98005, USA
| | - S Truelove
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - E Utazi
- WorldPop, Department of Geography and Environmental Science, University of Southampton, Highfield, Southampton SO17 1BJ, UK
| | - A Wesolowski
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - A K Winter
- Department of Epidemiology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
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Olugbade OT, Adeyemi AS, Adeoti AH, Ilesanmi OS, Gidado SO, Waziri NE, Aworh MK. Measles outbreaks and Supplemental Immunization Activities (SIAs): the Gwagwalada experience, Abuja 2015. Pan Afr Med J 2019; 32:10. [PMID: 30949285 PMCID: PMC6441473 DOI: 10.11604/pamj.supp.2019.32.1.13368] [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: 07/15/2017] [Accepted: 12/04/2017] [Indexed: 11/30/2022] Open
Abstract
Introduction In November 2015 a measles outbreak was detected in several clustered settlements during the Northern Measles Supplementary Immunization Activities (SIAs) campaign in Gwagwalada, Nigeria, a measles outbreak was detected. Six weeks later another outbreak with 17 cases was reported in a different settlement in the same area council in December 2015 and January 2016. An outbreak investigation was initiated to characterize the outbreak in terms of time and person and implement prevention and control measures. Methods Suspected cases were defined as any person in Gwagwalada with onset of fever and rash between 1st November 2015 and 12th January 2016. Probable cases were defined as suspected cases with 3 days of rash or known exposure to someone with laboratory-confirmed measles. Confirmed case patients were defined as suspected or probable cases with Koplik spots or positive titer for immunoglobulin (Ig) M antibody. We conducted house to house case search, contact tracing and reviewed hospital records at the health facilities to determine the socio-demographic characteristics, clinical presentation and vaccination status of the cases. Results Active case search between November 2015 and January 2016 as well as record review from January 2015 to January 2016 showed that there were 109 suspected and 10 confirmed case patients. We identified 66 cases during the first reported outbreak with a case fatality rate of 6% (4 deaths) while 17 cases were identified 6 weeks later. The epidemic curve indicated a person-to-person transmission. Conclusion There had been cases of measles from January 2015 to November 2015 prior to the reported measles outbreak. However there was an unusual increase in the number of measles cases during the measles SIAs in communities where children were missed. Vaccination of all eligible children in the affected wards was carried out. The area council authorities and primary healthcare team need to create awareness on the importance of measles vaccination and ensure that these communities are targeted and covered during subsequent SIAs.
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Affiliation(s)
| | - Adeniran Sunday Adeyemi
- Epidemiology and Surveillance Unit, Department of Primary Healthcare, Gwagwalada Area Council, Abuja, FCT, Nigeria
| | | | | | | | | | - Mabel Kamweli Aworh
- Nigeria Field Epidemiology and Laboratory Training Programme, Abuja, Nigeria.,Department of Veterinary and Pest Services, Federal Ministry of Agriculture & Rural Development, Abuja, Nigeria
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Targeting Adults for Supplementary Immunization Activities of Measles Control in Central China: A Mathematical Modelling Study. Sci Rep 2018; 8:16124. [PMID: 30382120 PMCID: PMC6208397 DOI: 10.1038/s41598-018-34461-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 10/18/2018] [Indexed: 11/17/2022] Open
Abstract
Routine immunizations and supplementary immunization activities (SIAs) have significantly improved measles control over the past two decades in China. Progress towards eliminating measles currently faces multiple challenges as the infection age increases, and adult-targeted SIA strategies are being considered. This study developed an age-stratified susceptible-exposed-infectious-recovered model using a recently published contact matrix to depict measles transmissions between individuals in seven age groups. Hubei, a high measles-incidence province in central China, was the selected setting. The baseline scenario was calibrated by fitting with the 2012–2015 age-stratified incidence data. SIAs targeting multiple age groups were simulated. Adult-targeted (>29 years) two-year SIA cycles produced the greatest annual incidence rate decrease, reducing incidences by half over a long timespan with 90% coverage levels. Incidences could remain below 10/100,000 until 2030 if SIAs were provided to individuals ≥6 years old with at least 50% coverage. These findings will help officials prioritize supplementary vaccination strategies. Public health officials in China should consider adult-to-adult transmissions and provide adult-targeted SIAs. Although officials have reported approximately 90% SIA coverage in the past, SIAs for the adult population should be provided on shorter intervals, particularly for the aging population with decreased immunity.
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29
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Winter AK, Wesolowski AP, Mensah KJ, Ramamonjiharisoa MB, Randriamanantena AH, Razafindratsimandresy R, Cauchemez S, Lessler J, Ferrari MJ, Metcalf CJE, Héraud JM. Revealing Measles Outbreak Risk With a Nested Immunoglobulin G Serosurvey in Madagascar. Am J Epidemiol 2018; 187:2219-2226. [PMID: 29878051 PMCID: PMC6166215 DOI: 10.1093/aje/kwy114] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 05/25/2018] [Indexed: 12/28/2022] Open
Abstract
Madagascar reports few measles cases annually and high vaccination campaign coverage. However, the underlying age profile of immunity and risk of a measles outbreak is unknown. We conducted a nested serological survey, testing 1,005 serum samples (collected between November 2013 and December 2015 via Madagascar’s febrile rash surveillance system) for measles immunoglobulin G antibody titers. We directly estimated the age profile of immunity and compared these estimates with indirect estimates based on a birth cohort model of vaccination coverage and natural infection. Combining these estimates of the age profile of immunity in the population with an age-structured model of transmission, we further predicted the risk of a measles outbreak and the impact of mitigation strategies designed around supplementary immunization activities. The direct and indirect estimates of age-specific seroprevalence show that current measles susceptibility is over 10%, and modeling suggests that Madagascar may be at risk of a major measles epidemic.
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Affiliation(s)
- Amy K Winter
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Amy P Wesolowski
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Keitly J Mensah
- Princeton Environmental Institute, Princeton University, Princeton, New Jersey
| | | | | | | | - Simon Cauchemez
- Mathematical Modeling of Infectious Diseases Unit, Institut Pasteur, Paris, France
| | - Justin Lessler
- Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland
| | - Matt J Ferrari
- Intercollege Graduate Degree Program in Ecology, Pennsylvania State University, University Park, Pennsylvania
| | - C Jess E Metcalf
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey
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31
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Kareva I, Karev G. From Experiment to Theory: What Can We Learn from Growth Curves? Bull Math Biol 2017; 80:151-174. [PMID: 29150759 DOI: 10.1007/s11538-017-0347-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 09/12/2017] [Indexed: 02/06/2023]
Abstract
Finding an appropriate functional form to describe population growth based on key properties of a described system allows making justified predictions about future population development. This information can be of vital importance in all areas of research, ranging from cell growth to global demography. Here, we use this connection between theory and observation to pose the following question: what can we infer about intrinsic properties of a population (i.e., degree of heterogeneity, or dependence on external resources) based on which growth function best fits its growth dynamics? We investigate several nonstandard classes of multi-phase growth curves that capture different stages of population growth; these models include hyperbolic-exponential, exponential-linear, exponential-linear-saturation growth patterns. The constructed models account explicitly for the process of natural selection within inhomogeneous populations. Based on the underlying hypotheses for each of the models, we identify whether the population that it best fits by a particular curve is more likely to be homogeneous or heterogeneous, grow in a density-dependent or frequency-dependent manner, and whether it depends on external resources during any or all stages of its development. We apply these predictions to cancer cell growth and demographic data obtained from the literature. Our theory, if confirmed, can provide an additional biomarker and a predictive tool to complement experimental research.
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Affiliation(s)
- Irina Kareva
- Mathematical and Computational Sciences Center, School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, USA.,EMD Serono, Merck KGaA, Billerica, MA, USA
| | - Georgy Karev
- National Center for Biotechnology Information, National Institutes of Health, Bethesda, MD, USA.
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Verguet S, Jones EO, Johri M, Morris SK, Suraweera W, Gauvreau CL, Jha P, Jit M. Characterizing measles transmission in India: a dynamic modeling study using verbal autopsy data. BMC Med 2017; 15:151. [PMID: 28793891 PMCID: PMC5550950 DOI: 10.1186/s12916-017-0908-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 07/03/2017] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Decreasing trends in measles mortality have been reported in recent years. However, such estimates of measles mortality have depended heavily on assumed regional measles case fatality risks (CFRs) and made little use of mortality data from low- and middle-income countries in general and India, the country with the highest measles burden globally, in particular. METHODS We constructed a dynamic model of measles transmission in India with parameters that were empirically inferred using spectral analysis from a time series of measles mortality extracted from the Million Death Study, an ongoing longitudinal study recording deaths across 2.4 million Indian households and attributing causes of death using verbal autopsy. The model was then used to estimate the measles CFR, the number of measles deaths, and the impact of vaccination in 2000-2015 among under-five children in India and in the states of Bihar and Uttar Pradesh (UP), two states with large populations and the highest numbers of measles deaths in India. RESULTS We obtained the following estimated CFRs among under-five children for the year 2005: 0.63% (95% confidence interval (CI): 0.40-1.00%) for India as a whole, 0.62% (0.38-1.00%) for Bihar, and 1.19% (0.80-1.75%) for UP. During 2000-2015, we estimated that 607,000 (95% CI: 383,000-958,000) under-five deaths attributed to measles occurred in India as a whole. If no routine vaccination or supplemental immunization activities had occurred from 2000 to 2015, an additional 1.6 (1.0-2.6) million deaths for under-five children would have occurred across India. CONCLUSIONS We developed a data- and model-driven estimation of the historical measles dynamics, CFR, and vaccination impact in India, extracting the periodicity of epidemics using spectral and coherence analysis, which allowed us to infer key parameters driving measles transmission dynamics and mortality.
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Affiliation(s)
- Stéphane Verguet
- Department of Global Health and Population, Harvard T.H. Chan School of Public Health, 665 Huntington Avenue, Boston, MA, USA.
| | - Edward O Jones
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
| | - Mira Johri
- University of Montreal Hospital Research Centre (CRCHUM), Montréal, Québec, Canada
- Department of Health Management, Evaluation and Policy, School of Public Health, University of Montreal, Montréal, Québec, Canada
| | - Shaun K Morris
- Division of Infectious Diseases, Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, Ontario, Canada
| | - Wilson Suraweera
- Center for Global Health Research, Saint Michael's Hospital and University of Toronto, Toronto, Ontario, Canada
| | | | - Prabhat Jha
- Center for Global Health Research, Saint Michael's Hospital and University of Toronto, Toronto, Ontario, Canada
| | - Mark Jit
- Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, UK
- Modelling and Economics Unit, Public Health England, London, UK
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Assessing age-dependent susceptibility to measles in Japan. Vaccine 2017; 35:3309-3317. [PMID: 28501456 DOI: 10.1016/j.vaccine.2017.05.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/10/2017] [Accepted: 05/03/2017] [Indexed: 12/20/2022]
Abstract
BACKGROUND Routine vaccination against measles in Japan started in 1978. Whereas measles elimination was verified in 2015, multiple chains of measles transmission were observed in 2016. We aimed to reconstruct the age-dependent susceptibility to measles in Japan so that future vaccination strategies can be elucidated. METHODS An epidemiological model was used to quantify the age-dependent immune fraction using datasets of vaccination coverage and seroepidemiological survey. The second dose was interpreted in two different scenarios, i.e., booster and random shots. The effective reproduction number, the average number of secondary cases generated by a single infected individual, and the age at infection were explored using the age-dependent transmission model and the next generation matrix. RESULTS While the herd immunity threshold of measles likely ranges from 90% to 95%, assuming that the basic reproductive number ranges from 10 to 20, the estimated immune fraction in Japan was below those thresholds in 2016, despite the fact that the estimates were above 80% for all ages. If the second dose completely acted as the booster shot, a proportion immune above 90% was achieved only among those aged 5years or below in 2016. Alternatively, if the second dose was randomly distributed regardless of primary vaccination status, a proportion immune over 90% was achieved among those aged below 25years. The effective reproduction number was estimated to range from 1.50 to 3.01 and from 1.50 to 3.00, respectively, for scenarios 1 and 2 in 2016; if the current vaccination schedule were continued, the reproduction number is projected to range from 1.50 to 3.01 and 1.39 to 2.78, respectively, in 2025. CONCLUSION Japan continues to be prone to imported cases of measles. Supplementary vaccination among adults aged 20-49years would be effective if the chains of transmission continue to be observed in that age group.
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Chong KC, Zhang C, Zee BCY, Luo T, Wang L, Tam GCH, Jia KM, Sun R, Wang MH, Guan X. Interpreting the transmissibility of measles in two different post periods of supplementary immunization activities in Hubei, China. Vaccine 2017; 35:1024-1029. [DOI: 10.1016/j.vaccine.2017.01.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 01/03/2017] [Accepted: 01/05/2017] [Indexed: 11/26/2022]
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Mounier-Jack S, Edengue JM, Lagarde M, Baonga SF, Ongolo-Zogo P. One year of campaigns in Cameroon: effects on routine health services. Health Policy Plan 2016; 31:1225-31. [PMID: 27175031 PMCID: PMC5035779 DOI: 10.1093/heapol/czw054] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/10/2016] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Targeted campaigns have been reported to disrupt routine health services in low- and middle-income countries. The objective of this study was to evaluate the average effect of public health campaigns over 1 year on routine services such as antenatal care, routine vaccination and outpatient services. METHOD We collected daily activity data in 60 health facilities in two regions of Cameroon that traditionally undergo different intensities of campaign activity, the Centre region (low) and the Far North (high), to ascertain effects on routine services. For each outcome, we restricted our analysis to the public health centres for which good data were available and excluded private health facilities given their small number. We used segment-linear regression to account for the longitudinal nature of the data, and assessed whether the number of routine activities decreased in health facilities during periods when campaigns occurred. The analysis controlled for secular trends and serial correlation. RESULTS We found evidence that vaccination campaigns had a negative impact on routine activities, decreasing outpatient visits when they occurred (Centre: -9.9%, P = 0.079; Far North: -11.6%, P = 0.025). The average negative effect on routine services [outpatient visits -18% (P = 0.02) and antenatal consultations -70% [P = 0.001]) was most pronounced in the Far North during 'intensive' campaigns that usually require high mobilization of staff. DISCUSSION With an increasing number of interventions delivered by campaigns and in the context of elimination and eradication targets, these are important results for countries and agencies to consider. Achieving disease control targets hinges on ensuring high uptake of routine services. Therefore, we suggest that campaigns should systematically monitor 'impact on routine services', while also devising concrete strategies to mitigate potential adverse effects.
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Affiliation(s)
| | | | - Mylene Lagarde
- London School of Hygiene & Tropical Medicine, London, UK
| | | | - Pierre Ongolo-Zogo
- Central Hospital, Yaoundé, Centre for Development of Best Practices in Health, Yaoundé, Cameroon
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Clements CJ, Soakai TS, Sadr-Azodi N. A review of measles supplementary immunization activities and the implications for Pacific Island countries and territories. Expert Rev Vaccines 2016; 16:161-174. [PMID: 27690704 DOI: 10.1080/14760584.2017.1237290] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
INTRODUCTION Standard measles control strategies include achieving high levels of measles vaccine coverage using routine delivery systems, supplemented by mass immunization campaigns as needed to close population immunity gaps. Areas covered: This review looks at how supplementary immunization activities (SIAs) have contributed to measles control globally, and asks whether such a strategy has a place in Pacific Islands today. Expert commentary: Very high coverage with two doses of measles vaccine seems to be the optimal strategy for controlling measles. By 2015, all but two Pacific Islands had introduced a second dose in the routine schedule; however, a number of countries have not yet reached high coverage with their second dose. The literature and the country reviews reported here suggest that a high coverage SIA combined with one dose of measles vaccine given in the routine system will also do the job. The arguments for and against the use of SIAs are complex, but it is clear that to be effective, SIAs need to be well designed to meet specific needs, must be carried out effectively and safely with very high coverage, and should, when possible, carry with them other public health interventions to make them even more cost-effective.
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Affiliation(s)
- C John Clements
- a School of Population Health, The University of Melbourne , Melbourne , Australia
| | - Taniela Sunia Soakai
- b Maternal and Child Health Unit, Public Health Division , Secretariat of the Pacific Community , Suva , Fiji
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Johri M, Verguet S, Morris SK, Sharma JK, Ram U, Gauvreau C, Jones E, Jha P, Jit M. Adding interventions to mass measles vaccinations in India. Bull World Health Organ 2016; 94:718-727. [PMID: 27843161 PMCID: PMC5043198 DOI: 10.2471/blt.15.160044] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2015] [Revised: 02/01/2016] [Accepted: 04/07/2016] [Indexed: 12/04/2022] Open
Abstract
OBJECTIVE To quantify the impact on mortality of offering a hypothetical set of technically feasible, high-impact interventions for maternal and child survival during India's 2010-2013 measles supplementary immunization activity. METHODS We developed Lives Saved Tool models for 12 Indian states participating in the supplementary immunization, based on state- and sex-specific data on mortality from India's Million Deaths Study and on health services coverage from Indian household surveys. Potential add-on interventions were identified through a literature review and expert consultations. We quantified the number of lives saved for a campaign offering measles vaccine alone versus a campaign offering measles vaccine with six add-on interventions (nutritional screening and complementary feeding for children, vitamin A and zinc supplementation for children, multiple micronutrient and calcium supplementation in pregnancy, and free distribution of insecticide-treated bednets). FINDINGS The measles vaccination campaign saved an estimated 19 016 lives of children younger than 5 years. A hypothetical campaign including measles vaccine with add-on interventions was projected to save around 73 900 lives (range: 70 200-79 300), preventing 73 700 child deaths (range: 70 000-79 000) and 300 maternal deaths (range: 200-400). The most effective interventions in the whole package were insecticide-treated bednets, measles vaccine and preventive zinc supplementation. Girls accounted for 66% of expected lives saved (12 712/19 346) for the measles vaccine campaign, and 62% of lives saved (45 721/74 367) for the hypothetical campaign including add-on interventions. CONCLUSION In India, a measles vaccination campaign including feasible, high-impact interventions could substantially increase the number of lives saved and mitigate gender-related inequities in child mortality.
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Affiliation(s)
- Mira Johri
- Centre de Recherche du Centre Hospitalier de l’Université de Montréal, Tour Saint-Antoine, Porte S03-458, 850 Rue St-Denis, Montréal, Québec, H2X 0A9, Canada
| | - Stéphane Verguet
- Department of Global Health and Population, Harvard TH Chan School of Public Health, Boston, United States of America
| | - Shaun K Morris
- Division of Infectious Diseases, Department of Pediatrics, University of Toronto, Toronto, Canada
| | - Jitendar K Sharma
- National Health Systems Resource Centre, Ministry of Health and Family Welfare, New Delhi, India
| | - Usha Ram
- Centre for Global Health Research, Dalla Lana School of Public Health, Toronto, Canada
| | - Cindy Gauvreau
- Centre for Global Health Research, Dalla Lana School of Public Health, Toronto, Canada
| | - Edward Jones
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, England
| | - Prabhat Jha
- Centre for Global Health Research, Dalla Lana School of Public Health, Toronto, Canada
| | - Mark Jit
- Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, England
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Corey KC, Noymer A. A 'post-honeymoon' measles epidemic in Burundi: mathematical model-based analysis and implications for vaccination timing. PeerJ 2016; 4:e2476. [PMID: 27672515 PMCID: PMC5028774 DOI: 10.7717/peerj.2476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/23/2016] [Indexed: 12/27/2022] Open
Abstract
Using a mathematical model with realistic demography, we analyze a large outbreak of measles in Muyinga sector in rural Burundi in 1988–1989. We generate simulated epidemic curves and age × time epidemic surfaces, which we qualitatively and quantitatively compare with the data. Our findings suggest that supplementary immunization activities (SIAs) should be used in places where routine vaccination cannot keep up with the increasing numbers of susceptible individuals resulting from population growth or from logistical problems such as cold chain maintenance. We use the model to characterize the relationship between SIA frequency and SIA age range necessary to suppress measles outbreaks. If SIAs are less frequent, they must expand their target age range.
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Affiliation(s)
- Katelyn C Corey
- Fielding School of Public Health, University of California , Los Angeles , CA , United States
| | - Andrew Noymer
- Department of Population Health and Disease Prevention, University of California , Irvine , CA , United States
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Thompson KM. Evolution and Use of Dynamic Transmission Models for Measles and Rubella Risk and Policy Analysis. RISK ANALYSIS : AN OFFICIAL PUBLICATION OF THE SOCIETY FOR RISK ANALYSIS 2016; 36:1383-1403. [PMID: 27277138 DOI: 10.1111/risa.12637] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The devastation caused by periodic measles outbreaks motivated efforts over more than a century to mathematically model measles disease and transmission. Following the identification of rubella, which similarly presents with fever and rash and causes congenital rubella syndrome (CRS) in infants born to women first infected with rubella early in pregnancy, modelers also began to characterize rubella disease and transmission. Despite the relatively large literature, no comprehensive review to date provides an overview of dynamic transmission models for measles and rubella developed to support risk and policy analysis. This systematic review of the literature identifies quantitative measles and/or rubella dynamic transmission models and characterizes key insights relevant for prospective modeling efforts. Overall, measles and rubella represent some of the relatively simplest viruses to model due to their ability to impact only humans and the apparent life-long immunity that follows survival of infection and/or protection by vaccination, although complexities arise due to maternal antibodies and heterogeneity in mixing and some models considered potential waning immunity and reinfection. This review finds significant underreporting of measles and rubella infections and widespread recognition of the importance of achieving and maintaining high population immunity to stop and prevent measles and rubella transmission. The significantly lower transmissibility of rubella compared to measles implies that all countries could eliminate rubella and CRS by using combination of measles- and rubella-containing vaccines (MRCVs) as they strive to meet regional measles elimination goals, which leads to the recommendation of changing the formulation of national measles-containing vaccines from measles only to MRCV as the standard of care.
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Hand, Foot, and Mouth Disease in China: Critical Community Size and Spatial Vaccination Strategies. Sci Rep 2016; 6:25248. [PMID: 27125917 PMCID: PMC4850478 DOI: 10.1038/srep25248] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 04/13/2016] [Indexed: 11/08/2022] Open
Abstract
Hand Foot and Mouth Disease (HFMD) constitutes a considerable burden for health care systems across China. Yet this burden displays important geographic heterogeneity that directly affects the local persistence and the dynamics of the disease, and thus the ability to control it through vaccination campaigns. Here, we use detailed geographic surveillance data and epidemic models to estimate the critical community size (CCS) of HFMD associated enterovirus serotypes CV-A16 and EV-A71 and we explore what spatial vaccination strategies may best reduce the burden of HFMD. We found CCS ranging from 336,979 (±225,866) to 722,372 (±150,562) with the lowest estimates associated with EV-A71 in the southern region of China where multiple transmission seasons have previously been identified. Our results suggest the existence of a regional immigration-recolonization dynamic driven by urban centers. If EV-A71 vaccines doses are limited, these would be optimally deployed in highly populated urban centers and in high-prevalence areas. If HFMD vaccines are included in China's National Immunization Program in order to achieve high coverage rates (>85%), routine vaccination of newborns largely outperforms strategies in which the equivalent number of doses is equally divided between routine vaccination of newborns and pulse vaccination of the community at large.
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