10 May 2021
This scientific brief replaces the WHO Scientific Brief entitled “’Immunity passports’ in the context of COVID-19”, published 24 April 2020.
This update is focused on what is currently understood about SARS-CoV-2 immunity from natural infection. More information about considera...tions on vaccine certificates or “passports” will be covered in an update of WHO interim guidance, as requested by the COVID-19 emergency committee.
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As the Americas undergo profound demographic change and there are more persons aged 65 years or older than children younger than 5 years, it is crucial to recognize that national immunization programs must be redesigned to ensure comprehensive protection for individuals across the lifespan. By adopt...ing a life course approach (LCA) to immunization, vaccination programs can be tailored to close immunity gaps at different stages of life. The life course approach foresees the establishment of multiple strategies to reduce missed opportunities for vaccination according to age group. This technical document explains the key concepts of the LCA with a focus on immunization by vaccination, as well as the underlying biological mechanisms that require the application different vaccines at different life stages according to changes to the immune system and in the epidemiological situation of a community.
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As new variants emerge people are wondering if they should wait until a more efficacious vaccine is available or if they should go ahead and get vaccinated now? Answering your questions on COVID-19 vaccines and variants in this episode of Science in 5 is WHO's Dr Soumya Swaminathan.
The Lancet, Early Online Publication, 11 July 2014
doi:10.1016/S0140-6736(14)60934-X
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Document d’information scientifique
24 avril 2020
Le développement d’une immunité face à un agent pathogène à la suite d’une infection naturelle comporte plusieurs étapes et prend généralement une à deux semaines. Une infection virale entraîne immédiatement une réponse immunit...aire innée, non spécifique, au cours de laquelle les macrophages, les neutrophiles et les cellules dendritiques ralentissent la progression du virus et peuvent même éviter l’apparition de symptômes. Cette réponse non spécifique est suivie d’une réponse adaptative, au cours de laquelle l’organisme produit des anticorps qui se lient spécifiquement au virus. Ces anticorps sont des protéines appelées immunoglobulines. L’organisme produit également des lymphocytes T qui reconnaissent et éliminent les cellules infectées par le virus. Cette réponse adaptative permet parfois d’éliminer le virus de l’organisme et, si elle est suffisamment forte, d’éviter l’aggravation de la maladie ou la réinfection par le même virus. Ce processus est souvent mesuré par la présence d’anticorps dans le sang.
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Herd immunity by mass vaccination offers the potential to substantially limit the continuing spread of COVID-19, but high levels of vaccine hesitancy threaten this goal. In a cross-country analysis of vaccine hesitant respondents across Latin America in January 2021, we experimentally tested how fiv...e features of mass vaccination campaigns—the vaccine’s producer, efficacy, endorser, distributor, and current population uptake rate—shifted willingness to take a COVID-19 vaccine. We find that citizens preferred Western-produced vaccines, but were highly influenced by factual information about vaccine efficacy. Vaccine hesitant individuals were more responsive to vaccine messengers with medical expertise than political, religious, or media elite endorsements. Citizen trust in foreign governments, domestic leaders, and state institutions moderated the effects of the campaign features on vaccine acceptance. These findings can help inform the design of unfolding mass inoculation campaigns.
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Natural immunity against COVID-19
Scientific report 10 May 2021
Vaccines are designed to give you immunity without the dangers of getting the disease. It’s common to experience some mild to moderate side effects when receiving vaccinations. This is because your immune system instructs your body to increase blood flow so more immune cells can circulate, and it ...raises your body temperature to kill the virus. Vaccines help protect us against disease and feeling mild or moderate side effects after receiving one is a sign that the vaccine and our immune system is working.
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Les vaccins sont conçus pour vous conférer une immunité sans les dangers d’avoir contracté la maladie. Il est courant de ressentir quelques effets indésirables légers à modérés après avoir reçu un vaccin. Ils sont dus au fait que votre système immunitaire demande à votre organisme d'a...ugmenter le flux sanguin afin que davantage de cellules immunitaires puissent circuler, et il élève votre température interne afin de tuer le virus. Les vaccins nous aident à nous protéger contre les maladies, et ressentir des effets indésirables légers ou modérés après avoir reçu un vaccin est un signe que ce vaccin et notre système immunitaire fonctionnent.
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COVID-19 vaccine hesitancy is currently one of the main obstacles to worldwide herd immunity and socioeconomic recovery. Because vaccine coverage can vary between and within countries, it is important
to identify sources of variation so that policies can be tailored to different population groups. ...In this paper, we analyze the results from a survey designed and implemented in order to identify early adopters and
laggers in six big cities of Latin America. We find that trust in government and science, accurate knowledge about the value of vaccination and vaccine effects, perceived risk of getting sick, and being a student
increase the odds to get vaccinated. We also identify potential laggers as women and populations between 20 and 35 years old who are not students. We discuss specific strategies to promote vaccination among
these populations groups as well as more general strategies designed to gain trust. These findings are specific to the context of Latin America insofar as the underlying factors associated with the choice to be
vaccinated vary significantly by location and in relation to individual-level factors.
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Elderly people are at a higher risk of COVID-19 infection due to their decreased immunity and body reserves, as well as multiple associated comorbidities like diabetes, hypertension, chronic kidney disease and chronic obstructive pulmonary disease. Also, course of disease tends to be more severe in ...case of elderlies resulting in higher mortality.
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26 March 2021 Slideset updated regularly to include the latest data on the evolution and duration of COVID-19 symptoms and prevalence and duration of natural immunity.
The backsliding of immunization coverage during the COVID-19 pandemic, combined with delayed catch-up efforts has resulted in a large and growing immunity gap. There is an urgent need to close this gap, and enable millions of missed children to be vaccinated. The Essential Immunization Recovery Plan... sets out a path to getting immunization back on track, framed by three key approaches – Catch-Up, Restore and Strengthen. This document serves as the joint strategic description of this coordinated effort by WHO, UNICEF, and Gavi, the Vaccine Alliance, along with the Immunization Agenda 2030 (IA2030) Partnership, to support countries to plan and implement intensified efforts to bolster immunization programmes in 2023 and beyond.
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There are currently 4 different serotypes of Dengue virus known to science. Each time someone get infected and recovers, the individual will be protected by a lifelong immunity from further infection against that specific serotype and that serotype only.
Consequent infection from different serotype... not only will infect the individual but may also cause a more serious or severe disease progression.
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Since the release of the first volume in May 2020, the COVID-19 pandemic has continued to rage around the world. By mid-March, 2021, countries around the globe had reported over 123 million cases—a nearly five-fold increase since this report’s previous volume—and over 2.7 million deaths attrib...uted to the disease. And while new case loads are currently on the rise again, the global health community has already administered almost 400 million doses of vaccines, at last offering some signs of hope and progress.
Economic impacts threaten to undo decades of recent progress in poverty reduction, child nutrition and gender equality, and exacerbate efforts to support refugees, migrants, and other vulnerable communities. National and local governments—together with international and private-sector partners—must deploy vaccines as efficiently, safely and equitably as possible while still monitoring for new outbreaks and continuing policies to protect those who do not yet have immunity.
More than ever, the world needs reliable and trustworthy data and statistics to inform these important decisions. The United Nations and all member organizations of the Committee for the Coordination of Statistical Activities (CCSA) collect and make available a wealth of information for assessing the multifaceted impacts of the pandemic. This report updates some of the global and regional trends presented in Volume I and offers a snapshot of how COVID-19 continues to affect the world today across multiple domains.
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COVID-19 is a pandemic that is currently ravaging the world. Infection rate is steadily increasingin Sub-Saharan Africa. Pregnant women and their infants may suffer severe illnesses due to theirlower immunity. This guideline prepares and equips clinicians working in the maternal and new-born section...s in the sub-region to manage COVID-19 during pregnancy and childbir
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One health Response to AMR Containment.
In a significant move for the public health sector, Kerala has become the first state in India to launch an action plan to combat the growing cases of antimicrobial immunity, arising primarily from irrational use of medicines and excessive antibiotics used in... livestock and poultry.
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WHO Guideline. Since 2010, countries in the meningitis belt have started to introduce a new serogroup A meningococcal conjugate vaccine conferring individual protection and herd immunity. Following the successful roll-out of this vaccine, epidemics due to Neisseria meningitidis serogroup A (NmA) are... disappearing, but other serogroups (e.g. NmW, NmX and NmC) still cause epidemics, albeit at a lower frequency and of a smaller size. Due to these changes, WHO organized the review of the evidence to provide recommendations for epidemic control, related to operational thresholds for investigation and response to outbreaks, the use of rapid diagnostic tests, antibiotic regimens in epidemics, and prophylaxis for household contacts of cases
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Les enfants malnutris courent trois fois plus de risque de mourir du choléra
Alors qu'une grande partie du pays est confrontée à une insécurité alimentaire croissante, les enfants souffrant de malnutrition aiguë ont un système immunitaire affaibli et courent au moins trois fois plus de ris...ques de mourir s'ils contractent le choléra, renforçant davantage la nécessité d'une action urgente pour contenir la maladie. Depuis que le choléra a été signalé pour la première fois le 2 octobre 2022, il y a eu 22 décès enregistrés dans les institutions sanitaires
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