{"id":5370,"date":"2021-02-09T11:49:05","date_gmt":"2021-02-09T10:49:05","guid":{"rendered":"http:\/\/collegevauban-blaye.fr\/?p=5370"},"modified":"2021-02-22T09:49:24","modified_gmt":"2021-02-22T08:49:24","slug":"covid-19-et-vaccins-a-arn","status":"publish","type":"post","link":"http:\/\/collegevauban-blaye.fr\/?p=5370","title":{"rendered":"Covid-19 et vaccins \u00e0 ARN"},"content":{"rendered":"\n\n<p style=\"text-align: center\"><strong>Article de vulgarisation scientifique \u00e0 destination des \u00e9l\u00e8ves et des parents\u2026 <\/strong><\/p>\n<p style=\"text-align: center\"><strong>S\u2019informer, comprendre et d\u00e9velopper son esprit critique afin de se forger sa propre opinion<\/strong><\/p>\n<p style=\"text-align: center\"><span style=\"color: #ff0000;font-size: 14pt\"><strong>Principe de la vaccination et m\u00e9moire immunitaire<\/strong><\/span><\/p>\n<p>Les vaccins \u00ab&nbsp;classiques&nbsp;\u00bb consistent \u00e0 injecter une forme att\u00e9nu\u00e9e ou inactiv\u00e9e du pathog\u00e8ne (virus ou bact\u00e9ries). Ce microbe \u00ab&nbsp;att\u00e9nu\u00e9&nbsp;\u00bb n\u2019est plus dangereux pour la sant\u00e9 mais qui d\u00e9clenche quand m\u00eame une r\u00e9action de d\u00e9fense de la part de l\u2019organisme. Lors de cette premi\u00e8re r\u00e9ponse immunitaire, des globules blancs (dont les lymphocytes B et T), sont mis <span style=\"color: #ff0000\"><strong>en m\u00e9moire<\/strong><\/span>. Lors d\u2019un deuxi\u00e8me contact avec le m\u00eame microbe, les globules blancs r\u00e9agissent beaucoup plus vite. La deuxi\u00e8me r\u00e9ponse immunitaire est donc beaucoup plus rapide et beaucoup plus forte. Les globules blancs d\u00e9truisent alors le microbe avant qu\u2019il n\u2019ait le temps de se multiplier.<img loading=\"lazy\" decoding=\"async\" class=\"wp-image-5369 aligncenter\" src=\"http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/Immuno-300x254.jpg\" alt=\"\" width=\"443\" height=\"375\" srcset=\"http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/Immuno-300x254.jpg 300w, http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/Immuno.jpg 512w\" sizes=\"auto, (max-width: 443px) 100vw, 443px\" \/><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-5380 aligncenter\" src=\"http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-2-300x164.jpg\" alt=\"\" width=\"728\" height=\"398\" srcset=\"http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-2-300x164.jpg 300w, http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-2-1024x560.jpg 1024w, http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-2-768x420.jpg 768w, http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-2.jpg 1403w\" sizes=\"auto, (max-width: 728px) 100vw, 728px\" \/><\/p>\n<p>&nbsp;<\/p>\n<p style=\"text-align: center\"><span style=\"color: #ff0000;font-size: 14pt\"><strong>De nouveaux vaccins&nbsp;: les vaccins \u00e0 ARN<\/strong><\/span><\/p>\n<p>Le vaccin \u00e0 ARN, ne consiste pas \u00e0 injecter un morceau du coronavirus SARS-CoV-2 responsable de la covid-19 mais un morceau de mat\u00e9riel g\u00e9n\u00e9tique du virus appel\u00e9 ARN messager (ARN m). Cet ARN p\u00e9n\u00e8tre dans les cellules humaines, au point d\u2019injection (surtout dans les cellules musculaires). Ces derni\u00e8res se mettent alors \u00e0 fabriquer une prot\u00e9ine virale&nbsp;: la <strong>prot\u00e9ine Spike<\/strong> (<strong>prot\u00e9ine de pointe<\/strong>)<\/p>\n<p>La prot\u00e9ine Spike fait partie de la \u00ab&nbsp;cl\u00e9 d\u2019entr\u00e9e&nbsp;\u00bb du virus dans les cellules humaines. Apr\u00e8s la vaccination, Les lymphocytes B, produisent rapidement et en grande quantit\u00e9, des anticorps qui se fixent sur la prot\u00e9ine Spike emp\u00eachant ainsi l\u2019entr\u00e9e du virus dans les cellules.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-5377 aligncenter\" src=\"http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-3-300x240.jpg\" alt=\"\" width=\"484\" height=\"387\" srcset=\"http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-3-300x240.jpg 300w, http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-3-1024x819.jpg 1024w, http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-3-768x614.jpg 768w, http:\/\/collegevauban-blaye.fr\/wp-content\/uploads\/2021\/02\/immuno-3.jpg 1080w\" sizes=\"auto, (max-width: 484px) 100vw, 484px\" \/>Cela fait plus de 10 ans que les chercheurs travaillent sur les vaccins \u00e0 ADN et \u00e0 ARN mais ils rencontraient des difficult\u00e9s techniques li\u00e9es \u00e0 la taille de ces morceaux de mat\u00e9riels g\u00e9n\u00e9tiques (plus gros que les mol\u00e9cules antig\u00e9niques utilis\u00e9es habituellement).<\/p>\n<p>En raison de la pand\u00e9mie de la covid-19, les moyens financiers mis dans la recherche, ont permis de progresser de mani\u00e8re spectaculaire.<\/p>\n<p><strong>Les points forts des vaccins \u00e0 ARN : <\/strong><\/p>\n<ul>\n<li>Ils sont beaucoup plus rapides \u00e0 fabriquer qu\u2019un vaccin classique<\/li>\n<\/ul>\n<ul>\n<li>Ils sont mieux tol\u00e9r\u00e9s par l\u2019organisme (sans ajout d\u2019adjuvant)<\/li>\n<\/ul>\n<ul>\n<li>Ils resteraient, plus ou moins efficaces, sur les nouveaux variants<\/li>\n<\/ul>\n<p><strong>Les points faibles des vaccins \u00e0 ARN&nbsp;:<\/strong><\/p>\n<ul>\n<li>L\u2019ARN est une mol\u00e9cule fragile, et la plupart des vaccins \u00e0 ARN n\u00e9cessitent une conservation \u00e0 des temp\u00e9ratures tr\u00e8s basses. Il faut donc respecter scrupuleusement la cha\u00eene du froid.<\/li>\n<\/ul>\n<ul>\n<li>Il s\u2019agit de vaccins r\u00e9cents et nous n\u2019avons pas, de vision \u00e0 long terme, de leurs effets secondaires \u00e9ventuels.<\/li>\n<\/ul>\n<p><strong>Aude Dubo\u00e9, professeure de SVT<\/strong><\/p>\n\n\n<figure class=\"wp-block-image size-large\"><\/figure>\n\n\n\n<figure class=\"wp-block-gallery columns-0 is-cropped wp-block-gallery-1 is-layout-flex wp-block-gallery-is-layout-flex\"><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>Article de vulgarisation scientifique \u00e0 destination des \u00e9l\u00e8ves et des parents\u2026 S\u2019informer, comprendre et d\u00e9velopper son esprit critique afin de se forger sa propre opinion Principe de la vaccination et m\u00e9moire immunitaire Les vaccins \u00ab&nbsp;classiques&nbsp;\u00bb consistent \u00e0 injecter une forme att\u00e9nu\u00e9e ou inactiv\u00e9e du pathog\u00e8ne (virus ou bact\u00e9ries). Ce microbe \u00ab&nbsp;att\u00e9nu\u00e9&nbsp;\u00bb n\u2019est plus dangereux pour &hellip; <\/p>\n<p class=\"link-more\"><a href=\"http:\/\/collegevauban-blaye.fr\/?p=5370\" class=\"more-link\">Continuer la lecture<span class=\"screen-reader-text\"> de &laquo;&nbsp;Covid-19 et vaccins \u00e0 ARN&nbsp;&raquo;<\/span><\/a><\/p>\n","protected":false},"author":6,"featured_media":5428,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[14],"tags":[],"class_list":["post-5370","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-sciences"],"_links":{"self":[{"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=\/wp\/v2\/posts\/5370","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=\/wp\/v2\/users\/6"}],"replies":[{"embeddable":true,"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=5370"}],"version-history":[{"count":9,"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=\/wp\/v2\/posts\/5370\/revisions"}],"predecessor-version":[{"id":5429,"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=\/wp\/v2\/posts\/5370\/revisions\/5429"}],"wp:featuredmedia":[{"embeddable":true,"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=\/wp\/v2\/media\/5428"}],"wp:attachment":[{"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=5370"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=5370"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/collegevauban-blaye.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=5370"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}