{"id":122,"date":"2020-10-14T22:56:00","date_gmt":"2020-10-14T22:56:00","guid":{"rendered":"https:\/\/covidqanda.org\/?p=122"},"modified":"2020-11-08T23:00:02","modified_gmt":"2020-11-08T23:00:02","slug":"what-does-reinfection-mean-for-a-vaccine","status":"publish","type":"post","link":"https:\/\/covidqanda.org\/?p=122","title":{"rendered":"What does reinfection mean for a vaccine?"},"content":{"rendered":"\n<p class=\"wp-block-paragraph\" id=\"c159\"><strong>Question:<\/strong>&nbsp;I read&nbsp;<a href=\"https:\/\/www.npr.org\/sections\/coronavirus-live-updates\/2020\/10\/12\/922980490\/scientists-confirm-nevada-man-was-infected-twice-with-coronavirus?utm_medium=RSS&amp;utm_campaign=news&amp;mc_cid=b430ae3391&amp;mc_eid=4ddcafff1e\">this article<\/a>&nbsp;from NPR, \u201cScientists Confirm Nevada Man Was Infected Twice With Coronavirus,\u201d with interest and disappointment. If it\u2019s proven that folks can get reinfected with the virus just a couple months after the first infection, doesn\u2019t this bode poorly for the efficacy of a vaccine?<\/p>\n\n\n\n<p class=\"wp-block-paragraph\" id=\"ae3c\"><strong>Answer:&nbsp;<\/strong>This Monday,&nbsp;<em>Lancet&nbsp;<\/em>published&nbsp;<a href=\"https:\/\/www.thelancet.com\/journals\/laninf\/article\/PIIS1473-3099(20)30764-7\/fulltext\">a case study<\/a>&nbsp;of the first confirmed COVID-19 reinfection in the United States. This case study adds to a small but growing body of evidence that reinfection can occur. In my opinion, the main take-away is that even if you have already been infected with SARS-CoV-2, you should still continue to practice public health prevention measures \u2014 masks, distancing, hand washing. When it comes to vaccines, the take-away is less clear cut; I suggest setting aside your disappointment until we know more. Here\u2019s the deal, as synthesized from an&nbsp;<a href=\"https:\/\/www.thelancet.com\/journals\/laninf\/article\/PIIS1473-3099(20)30783-0\/fulltext#section-7c530872-6235-4433-899c-b3f276970189\">accompanying commentary<\/a>&nbsp;that&nbsp;<em>Lancet<\/em>&nbsp;published, \u201cWhat reinfections mean for COVID-19,\u201d as well as an&nbsp;<a href=\"https:\/\/www.scientificamerican.com\/article\/what-covid-19-reinfection-means-for-vaccines\/\">article published in&nbsp;<em>Scientific American<\/em><\/a>&nbsp;three weeks ago, \u201cWhat COVID-19 reinfection means for vaccines,\u201d and an&nbsp;<a href=\"https:\/\/www.nature.com\/articles\/d41586-020-02506-y\">article published in&nbsp;<em>Nature<\/em><\/a>last month, \u201cCoronavirus reinfection: three questions scientists are asking.\u201d<\/p>\n\n\n\n<ul class=\"wp-block-list\"><li><strong>What are the odds of reinfection?&nbsp;<\/strong>So far, we have very few case studies to draw inferences from (N=5). Is this because reinfection is truly extremely rare or because we are only now in a position to experience and monitor reinfection (because time has elapsed, 2nd waves are occuring, and testing\/genomic analysis systems are more widely available)? We need more time and data to know the answer. Based on current evidence, the odds of reinfection seem miniscule, but absence of evidence is not evidence of absence. Reinfection for other types of coronaviruses is the norm.<\/li><li><strong>Why does reinfection occur?<\/strong>&nbsp;We don\u2019t know. One hypothesis is that reinfection occurs in those who have limited antibodies after first infection. Another is that antibody response quickly wanes, leaving an individual unprotected against future exposure. We need to measure the level of antibodies present at time of reinfection to test these hypotheses.<\/li><li><strong>Are people less likely to experience severe disease upon reinfection?<\/strong>&nbsp;So far, it\u2019s a mixed bag. Of the five cases, two experienced more severe disease upon reinfection. Of course, there are likely a number of people reinfected asymptomatically, who likely wouldn\u2019t show up in estimates, so these few cases we have monitored are already biased towards those with severe disease and come to the hospital. Among the two cases who did experience more severe disease upon reinfection, we still don\u2019t know why. Were they exposed to higher levels of the virus? Were there changes to their underlying health? Did a variant of SARS-CoV-2 produce more severe disease? Did their immune system somehow make things worse, like through an antibody-dependent enhancement? We need more data.<\/li><li><strong>Does infection by different viral isolates mean we need a vaccine for each type?&nbsp;<\/strong>As&nbsp;<a href=\"https:\/\/www.thelancet.com\/journals\/laninf\/article\/PIIS1473-3099(20)30783-0\/fulltext#section-7c530872-6235-4433-899c-b3f276970189\">written in the&nbsp;<em>Lancet&nbsp;<\/em>commentary<\/a>, \u201cThere is currently no evidence that a SARS-CoV-2 variant has emerged as a result of immune evasion. For now, one vaccine will be sufficient to confer protection against all circulating variants. Furthermore, reinfection by a distinct viral variant from the original virus does not imply immune escape.\u201d Note: \u201cimmune escape\u201d aka \u201cimmune evasion\u201d is the ability of a virus to evade a person\u2019s immune system and continue to grow\/spread.<\/li><li><strong>Can those who are reinfected spread the virus to others?<\/strong>&nbsp;Limited data point to yes, based on viral load detected among those reinfected. We do not, however, have any case studies of a reinfected person transmitting infection.<\/li><li><strong>What does reinfection mean for vaccine development?&nbsp;<\/strong>We need more information on reinfection to really answer this question. That said, based on what we currently know, it\u2019s looking possible that we may need to have booster shots as our immunity wanes and\/or we may need to have new generations of the vaccine to respond to new variants (as we have with flu). These developments would mean more logistic hurdles, which are surmountable. If we do see far more reinfections and more severe outcomes upon reinfection, the possibility that SARS-CoV-2 tampers with our immune memory increases, and this would have far more problematic vaccine ramifications. Given the vaccine trials underway and the safety data collected to date, this possibility seems extremely unlikely. Finally, vaccine induced immunity is more powerful than immunity induced by natural exposure. As Yale professor of immunobiology, Dr. Iwaskai,&nbsp;<a href=\"https:\/\/www.npr.org\/sections\/coronavirus-live-updates\/2020\/10\/12\/922980490\/scientists-confirm-nevada-man-was-infected-twice-with-coronavirus?utm_medium=RSS&amp;utm_campaign=news&amp;mc_cid=b430ae3391&amp;mc_eid=4ddcafff1e\">told NPR<\/a>, \u201cThe good thing about a vaccine is that it can induce much better immunity, a much longer lasting immunity, than the natural exposure to the virus.\u201d If we\u2019re lucky, one shot will do the trick!<\/li><\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Question:&nbsp;I read&nbsp;this article&nbsp;from NPR, \u201cScientists Confirm Nevada Man Was Infected Twice With Coronavirus,\u201d with interest and disappointment. If it\u2019s proven that folks can get reinfected with the virus just a couple months after the first infection, doesn\u2019t this bode poorly for the efficacy of a vaccine? Answer:&nbsp;This Monday,&nbsp;Lancet&nbsp;published&nbsp;a case study&nbsp;of the first confirmed COVID-19 reinfection [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":123,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[38,64],"tags":[65],"class_list":["post-122","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-immunity","category-vaccines","tag-reinfection","fallback-thumbnail"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/i0.wp.com\/covidqanda.org\/wp-content\/uploads\/2020\/11\/October-14.jpg?fit=290%2C174&ssl=1","_links":{"self":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts\/122","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=122"}],"version-history":[{"count":1,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts\/122\/revisions"}],"predecessor-version":[{"id":124,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/posts\/122\/revisions\/124"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=\/wp\/v2\/media\/123"}],"wp:attachment":[{"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=122"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=122"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/covidqanda.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=122"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}