Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries

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

Reverse Engineering for Manufacturing Approach: Based on the Combination of 3D and Knowledge Information

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Matching algorithm in the Reverse Engineering context

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Maintenance Conditionnelle en-ligne de systèmes à plusieurs modes de dégradation

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Maintenance policy on a finite time span for a gradually deteriorating system with imperfect improvements

International audienceThe study deals with a gradually deteriorating system such as a large structure. This system is studied over a finite time span where the finite horizon can be seen, for example, as an insurance deadline which requires a specific maintenance policy. Maintenance actions are assumed to be imperfect in this work. An improvement function is used to model the impact of the maintenance on the degradation level of the system. The improvement function is based in the virtual age model ARA1. A maintenance policy is then proposed in which maintenance actions are systematically performed at given maintenance dates, if the system has not already failed. It is assumed that in the event of a failure the system is not repaired. The system is then unavailable until the finite horizon. The proposed maintenance policy is assessed on the finite time span, and both maintenance dates and the number of maintenance actions are optimized

Assessment of a control limit maintenance decision rule for a multi deteriorating mode system

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Imperfect condition-based maintenance on a finite time span for a gradually deteriorating system

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Assessment of an imperfect maintenance policy on a finite time span

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An extension of the core product model for the maturity management of the digital mock up: use of graph and knowledge to describe mechanical parts

International audienceReverse engineering (RE) of mechanical parts consists in creating a 3D virtual model using data that are often gathered by 3D measurement systems like laser scanners. The resulting point cloud is then transformed into a geometrical model. The purpose of RE activity is to make maintenance or redesign operations easier. The boundary of the literature is the component, isolated from its product assembly. Because of unreported on-field maintenance, a long time running in-use product may not reflect its digital mock-up (DMU) anymore. In order to maintain an efficient lifecycle, the changes made have to be considered. This paper focuses on the development of a knowledge-based RE methodology to support the DMU maturity management: to identify the maturity defaults, which correspond to unreported changes, in the CAD assembly model in order to make it matching the real product. That approach is supported by a core product model data model extension

3D Information Management Enabling Manufacture Engineering

International audienceIndustrial companies are confronted to reverse engineering on mechanical components. They have to define a new process planning from 3D information (points cloud, drawings, etc.). The component has to be re-engineered in order to improve and optimize new manufacturing processes. According to surveys, reverse engineering approaches begin to be supported by Knowledge Base engineering Systems (KBS). These systems are efficient to quickly obtain CAD models based on functional features. These models are successful for redesigning activities and then for defining a process planning. Industrial companies often need to re-engineered components in order to define directly a new process planning. In this case CAD models, based on functional features, are not useful. This paper suggests an approach called Reverse Engineering For Manufacturing (REFM) which allows to directly obtain a CAPP (Computer Aided Process Planning) model from 3D information. The system management is based on Design For Manufacturing (DFM) approach and enables to manage manufacturing information (such as the number of fixtures, the kind of milling operations, etc.). In addition, this system management allows to define process planning alternatives. The aim of the paper is to show the concept of REFM approach according to a use case