{"id":49775,"date":"2021-03-10T09:36:23","date_gmt":"2021-03-10T08:36:23","guid":{"rendered":"https:\/\/blogs.bmj.com\/bmj\/?p=49775"},"modified":"2021-03-22T11:01:45","modified_gmt":"2021-03-22T10:01:45","slug":"covid-19-and-vaccines-known-unknowns","status":"publish","type":"post","link":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/","title":{"rendered":"Covid-19 and vaccines\u2014known unknowns"},"content":{"rendered":"<p><i><span style=\"font-weight: 400\">On 25 February 2021, <\/span><\/i><span style=\"font-weight: 400\">The BMJ <\/span><i><span style=\"font-weight: 400\">hosted <a href=\"https:\/\/www.youtube.com\/watch?v=irSU3a_pVsA\">a webinar on covid-19 vaccines<\/a>. An expert panel discussed the safety and efficacy of the vaccines, as well as dose schedules and obstacles to global distribution. Nikki Nabavi and Juliet Dobson report<\/span><\/i><\/p>\n<p><span style=\"font-weight: 400\">The webinar was inspired by an editorial published in <\/span><i><span style=\"font-weight: 400\">The BMJ<\/span><\/i><span style=\"font-weight: 400\"> entitled \u201c<\/span><a href=\"https:\/\/www.bmj.com\/content\/371\/bmj.m3979\"><span style=\"font-weight: 400\">Covid-19\u2019s known unknowns<\/span><\/a><span style=\"font-weight: 400\">.\u201d The key message: \u201cThe more certain someone is about covid-19, the less you should trust them.\u201d <strong><a href=\"https:\/\/www.bmj.com\/covid-19-webinars\">Register for future events here<\/a>.\u00a0<\/strong><\/span><\/p>\n<p><iframe loading=\"lazy\" title=\"Covid19 Known Unknowns: Vaccines\" width=\"640\" height=\"360\" src=\"https:\/\/www.youtube.com\/embed\/irSU3a_pVsA?start=2&#038;feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/p>\n<p><span style=\"font-weight: 400\">Before diving into discussions on the covid unknowns relating to vaccines, Richard Malley, from Boston Children\u2019s Hospital, summarised what we know: \u201cWe have three vaccines currently authorised in Europe and in the US, and several others in selected settings and in other countries. We have seen, and are still seeing, more evidence of efficacy in clinical trials, with [some] limitations. We&#8217;re also getting some preliminary effectiveness data in real life, in different settings in Israel, in the UK. And, very importantly, there are more vaccines on the way.\u201d\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">He described some of the unknowns as \u201cthe impact on transmission or asymptomatic infection, the duration of protection, and the possible need for boosters; who should be prioritised; the issue of delaying the second dose, the full versus the half dose, the coverage of variants, and whether boosters will be required that will cover these variants. And then also, what to do with an individual who has recovered from covid\u2014when should they be vaccinated and with how many doses.\u201d<\/span><\/p>\n<p><b>Safety and efficacy\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400\">Susanne Hodgson, Oxford University, started by clarifying the difference between efficacy (how well your vaccine works in a clinical trial setting) and effectiveness (how well your vaccine works in a real life scenario). She explained the importance of understanding the possible endpoints and how well each vaccine works against each endpoint. \u201cIf a person becomes exposed to a virus, the vaccine could prevent infection. If you are infected, a vaccine could reduce the likelihood of you developing symptoms. And if you do become symptomatic, a vaccine could modify the severity of the disease, and indeed whether you die from that infection or not. The vaccine could also modify the likelihood that you transmit infection onto other people.\u201d She shared the efficacy of some of the current vaccines, and their efficacy particularly in older age groups, noting that the Oxford AstraZeneca vaccine has not yet reported efficacy in this age group, as the researchers had only five cases in patients older than 55.<\/span><\/p>\n<p><span style=\"font-weight: 400\">Hodgson said: \u201cWe really needed a disease modifying vaccine because the mortality and morbidity associated with covid are what is causing such chaos\u2014but ideally, we also want a <\/span><span style=\"font-weight: 400\">vaccine that is capable of preventing infection, so that we can really have an impact on transmission and control this pandemic.\u201d\u00a0 She explained the importance of understanding both symptomatic and asymptomatic infections in randomised controlled trials.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">\u201cFull transparency is a prerequisite for a science based vaccination programme,\u201d said Peter Doshi, University of Maryland and <\/span><i><span style=\"font-weight: 400\">The BMJ<\/span><\/i><span style=\"font-weight: 400\">. What do we mean when we ask if the vaccine \u201cworks\u201d and\u00a0 agreed with Hodgson that there are two desired possible outcomes\u2014reducing hospital admissions (ICU admissions and deaths), as well as leading towards some form of herd immunity\u2014but reminded us that\u00a0 the randomised controlled trials \u201cwere not designed to study either.\u201d At best, he suggested, we might get some hints from randomised control trials, but definitive answers \u201cremain elusive, and non-randomised, observational studies will fill this [information] void.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">Doshi outlined the fact that the vaccine trials all say that they will be making their data published and available, although many of these will not be released for a very long time. \u201cMost are tying the data release to the end of the trial.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">Ben Goldacre spoke about OpenSAFELY, \u201ca new, fully open source, highly secure data analytics platform that we&#8217;ve built during the covid-19 pandemic, which contains an unprecedented scale of data.\u201d He spoke of the privacy challenges around so much data, such as patient identification.\u00a0<\/span><\/p>\n<p><b>Dose schedule\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400\">Malley explored first why so many options exist for the dose schedule. He described the limitations that the vaccines have, such as stability issues. \u201cFor example, for Pfizer it is the maturing of vaccines, although they&#8217;re trying to address many of these,\u201d or the price of the vaccine, which is \u201ca big deal for the developing world.\u201d He then mentioned some \u201cimmunological unknowns.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">Malley and Adam Finn believe that giving more of the vulnerable people their first dose of the vaccine for now confers better protection for the entire population. Malley shared some assumptions relating to the dose schedule. \u201cOne that I believe is incorrect is that clinical trials determine the optimal schedule,\u201d . . . \u201cthe reality is that these numbers are almost picked out of a hat.\u201d Malley said that \u201cthe second fallacy is that the schedule shouldn&#8217;t be messed with,\u201d but explained that this differs \u201cgreatly across different countries, and we are not seeing that any one country is seeing significantly better results of vaccination than others.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">\u201cA third fallacy is that the protection that was seen after the first dose will disappear if you don&#8217;t give a second dose on schedule,\u201d he added.<\/span><\/p>\n<p><b>Equity and obstacles to vaccine distribution and reach\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400\">Carlos Correa focused on the intellectual property of covid-19 vaccines. He explained that the UN and other international agencies decided that \u201call products related to covid-19 should be considered global public goods. So the idea was that there should be no appropriation of vaccines or protective equipment or diagnostic kits, for example. The world should work in the direction of allowing everybody to use whatever technologies and allow inventions related to covid-19 products.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">But \u201cintellectual property is crucial for innovation. If there is no threat to property, we are not going to produce new vaccines or improve them, and therefore we actually need to ensure that intellectual property is granted.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">Priti Patnaik spoke <\/span><span style=\"font-weight: 400\">about equity and obstacles to access to covid-19 vaccines. She asked what some of the global mechanisms are\u00a0 that have been put in place to tackle the question of equitable access and the potential obstacles to equity we face today\u2014and is equity even possible? She highlighted the COVAX initiative, and how fewer doses have become available than expected.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">David Himmelstein spoke about the situation in the US, where the private healthcare system has, \u201cresulted in a really disastrous health system in the face of this pandemic.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">\u201cWe really have no organisation of care. And despite the Affordable Care Act, we still had 30 million uninsured at the outset of the pandemic. So we had an utter lack of primary care infrastructure that we could rely on to distribute the vaccine. And overlaid on that was a historic distrust of the health care system by poor people and particularly by people of colour,\u201d he said.\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">He discussed the impact of \u201cvery low vaccine coverage rates among those who should be vaccinated, among black people, Hispanic people, and Native Americans. And even in the healthcare workforce, we see that pattern . . . refusing to be vaccinated even when it&#8217;s offered at no cost, because of their longstanding suspicion and exclusion from the healthcare system.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">At the other end of the spectrum \u201cconcierge medical practices\u201d are \u201cadministering the vaccine in large numbers to people at lowest risk because they are the most privileged members of those practices and executives in that firm getting to the front of the queue.\u201d<\/span><\/p>\n<p><span style=\"font-weight: 400\">Finally, he said that the US \u201chad a year of complete neglect under the Trump administration, which made absolutely no preparation for the distribution of the vaccine in any parts of our healthcare system.\u201d<\/span><\/p>\n<p><b>Possible futures<\/b><\/p>\n<p><span style=\"font-weight: 400\">Chadi Saad-Roy and Caroline Wagner discussed modelling of <\/span><span style=\"font-weight: 400\">immune responses to SARSars-CoV-2 and what that shows in terms of longer term epidemiological predictions<\/span><span style=\"font-weight: 400\">. M<\/span><span style=\"font-weight: 400\">odels show that \u201cthe burden and timing of covid-19 infections, a potential for viral adaptation, will depend on what adaptive immune responses look like and how long they last . . . . Overall, the models seem to reflect that a one dose strategy is good in the short term in terms of mitigating the number of cases because you immunise more people. But in the longer term, outcomes will depend on the relative robustness of what the first dose can do. So our models show that if you can switch to a two dose strategy as vaccines become more available, that might help to mitigate those outcomes. This obviously clearly illustrates that we have to rapidly and equitably distribute vaccines because the potential for evolution in one place will undermine efforts made anywhere else.\u201d<\/span><\/p>\n<p><strong>This webinar was part of\u00a0<a href=\"https:\/\/www.bmj.com\/covid-19-webinars\"><em>The BMJ<\/em>\u2018s series of covid-19 known, unknowns webinars<\/a>. Find out more and register for future events\u00a0<a href=\"https:\/\/www.bmj.com\/covid-19-webinars\">here<\/a>.\u00a0<\/strong><\/p>\n<p><em><strong>Nikki Nabavi<\/strong>, editorial scholar, The BMJ<\/em><\/p>\n<p><em><strong>Juliet Dobson<\/strong>, editor\u00a0<a class=\"vglnk\" href=\"http:\/\/bmj.com\/\" rel=\"nofollow\">bmj.com<\/a>, The BMJ<\/em><\/p>\n<p><em><strong>Competing interests<\/strong>: none declared.<\/em><\/p>\n<p><span style=\"font-weight: 400\">&#8212;<\/span><\/p>\n<p><b>Safety and efficacy\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400\">Chair: Rajeka Lazarus, University Hospital of Bristol and Weston<\/span><\/p>\n<p><span style=\"font-weight: 400\">Susanne Hodgson (Oxford University)<\/span><\/p>\n<p><span style=\"font-weight: 400\">Peter Doshi (University of Maryland\/The BMJ)\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">Ben Goldacre (Nuffield Department of Primary Care and Health Sciences<\/span><\/p>\n<p><b>Dose schedule\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400\">Chair: Adam Finn, JCVI, University of Bristol<\/span><\/p>\n<p><span style=\"font-weight: 400\">Richard Malley (Boston Children\u2019s Hospital)<\/span><\/p>\n<p><b>Equity and obstacles to vaccine distribution and reach\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400\">Chair: Allyson Pollock<\/span><\/p>\n<p><span style=\"font-weight: 400\">Carlos Correa (Intergovernmental South Centre)<\/span><\/p>\n<p><span style=\"font-weight: 400\">Priti Patnaik (Geneva Health Files)\u00a0<\/span><\/p>\n<p><span style=\"font-weight: 400\">David Himmelstein (City University, New York)<\/span><\/p>\n<p><b>Possible futures<\/b><span style=\"font-weight: 400\">:<\/span><\/p>\n<p><span style=\"font-weight: 400\">Chair: George Davey Smith<\/span><\/p>\n<p><span style=\"font-weight: 400\">Chadi Saad-Roy and Caroline Wagner (Princeton University)<\/span><\/p>\n<p><span style=\"font-weight: 400\">Sheila Bird (University of Edinburgh)<\/span><\/p>\n<p><b>Discussion\/Q&amp;A\u00a0<\/b><\/p>\n<p><span style=\"font-weight: 400\">Chair: Phil Hammond<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>On 25 February 2021, The BMJ hosted a webinar on covid-19 vaccines. An expert panel discussed the safety and efficacy of the vaccines, as well as dose schedules and obstacles [&#8230;]<\/p>\n<p><a class=\"btn btn-secondary understrap-read-more-link\" href=\"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/\">More&#8230;<\/a><\/p>\n","protected":false},"author":66,"featured_media":49431,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[18932],"tags":[],"class_list":["post-49775","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-covid-19-known-unknowns-webinars"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.4 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>Covid-19 and vaccines\u2014known unknowns - The BMJ<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Covid-19 and vaccines\u2014known unknowns - The BMJ\" \/>\n<meta property=\"og:description\" content=\"On 25 February 2021, The BMJ hosted a webinar on covid-19 vaccines. An expert panel discussed the safety and efficacy of the vaccines, as well as dose schedules and obstacles [...]More...\" \/>\n<meta property=\"og:url\" content=\"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/\" \/>\n<meta property=\"og:site_name\" content=\"The BMJ\" \/>\n<meta property=\"article:publisher\" content=\"https:\/\/www.facebook.com\/bmjdotcom\/\" \/>\n<meta property=\"article:published_time\" content=\"2021-03-10T08:36:23+00:00\" \/>\n<meta property=\"article:modified_time\" content=\"2021-03-22T10:01:45+00:00\" \/>\n<meta property=\"og:image\" content=\"https:\/\/blogs.bmj.com\/bmj\/files\/2021\/01\/coronavirus_pfizer_vaccine_PA-57616467.jpg\" \/>\n\t<meta property=\"og:image:width\" content=\"540\" \/>\n\t<meta property=\"og:image:height\" content=\"350\" \/>\n\t<meta property=\"og:image:type\" content=\"image\/jpeg\" \/>\n<meta name=\"author\" content=\"julietwalker\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:creator\" content=\"@bmj_latest\" \/>\n<meta name=\"twitter:site\" content=\"@bmj_latest\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"julietwalker\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"7 minutes\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"Article\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#article\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/\"},\"author\":{\"name\":\"julietwalker\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#\\\/schema\\\/person\\\/373707d32533c2cbca204980b8cd3493\"},\"headline\":\"Covid-19 and vaccines\u2014known unknowns\",\"datePublished\":\"2021-03-10T08:36:23+00:00\",\"dateModified\":\"2021-03-22T10:01:45+00:00\",\"mainEntityOfPage\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/\"},\"wordCount\":1586,\"commentCount\":0,\"publisher\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#organization\"},\"image\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/files\\\/2021\\\/01\\\/coronavirus_pfizer_vaccine_PA-57616467.jpg\",\"articleSection\":[\"Covid-19 known unknowns webinars\"],\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"CommentAction\",\"name\":\"Comment\",\"target\":[\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#respond\"]}]},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/\",\"url\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/\",\"name\":\"Covid-19 and vaccines\u2014known unknowns - The BMJ\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#website\"},\"primaryImageOfPage\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#primaryimage\"},\"image\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#primaryimage\"},\"thumbnailUrl\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/files\\\/2021\\\/01\\\/coronavirus_pfizer_vaccine_PA-57616467.jpg\",\"datePublished\":\"2021-03-10T08:36:23+00:00\",\"dateModified\":\"2021-03-22T10:01:45+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#breadcrumb\"},\"inLanguage\":\"en-US\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/\"]}]},{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#primaryimage\",\"url\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/files\\\/2021\\\/01\\\/coronavirus_pfizer_vaccine_PA-57616467.jpg\",\"contentUrl\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/files\\\/2021\\\/01\\\/coronavirus_pfizer_vaccine_PA-57616467.jpg\",\"width\":540,\"height\":350,\"caption\":\"Illustration shows a hand with a glove holding a dose of the vaccine at the vaccination of the staff members of the UZ Brussels University Hospital with the Covid-19 vaccine of Pfizer-BioNTech, in Jette, Brussels, Tuesday 19 January 2021. Members of the staff in contact with potentially coronavirus infected patients are the first to be vaccinated. BELGA PHOTO HATIM KAGHAT\"},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/2021\\\/03\\\/10\\\/covid-19-and-vaccines-known-unknowns\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"Covid-19 and vaccines\u2014known unknowns\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#website\",\"url\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/\",\"name\":\"The BMJ\",\"description\":\"Helping doctors make better decisions.\",\"publisher\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#organization\"},\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"en-US\"},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#organization\",\"name\":\"The BMJ\",\"url\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/\",\"logo\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#\\\/schema\\\/logo\\\/image\\\/\",\"url\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/files\\\/2018\\\/05\\\/The-BMJ-logo.jpg\",\"contentUrl\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/files\\\/2018\\\/05\\\/The-BMJ-logo.jpg\",\"width\":852,\"height\":568,\"caption\":\"The BMJ\"},\"image\":{\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#\\\/schema\\\/logo\\\/image\\\/\"},\"sameAs\":[\"https:\\\/\\\/www.facebook.com\\\/bmjdotcom\\\/\",\"https:\\\/\\\/x.com\\\/bmj_latest\"]},{\"@type\":\"Person\",\"@id\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/#\\\/schema\\\/person\\\/373707d32533c2cbca204980b8cd3493\",\"name\":\"julietwalker\",\"image\":{\"@type\":\"ImageObject\",\"inLanguage\":\"en-US\",\"@id\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/34f10b717c81464cc7a2879c84cd30078f63b5a901e12905a02abd9d1ea9ec90?s=96&d=mm&r=g\",\"url\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/34f10b717c81464cc7a2879c84cd30078f63b5a901e12905a02abd9d1ea9ec90?s=96&d=mm&r=g\",\"contentUrl\":\"https:\\\/\\\/secure.gravatar.com\\\/avatar\\\/34f10b717c81464cc7a2879c84cd30078f63b5a901e12905a02abd9d1ea9ec90?s=96&d=mm&r=g\",\"caption\":\"julietwalker\"},\"url\":\"https:\\\/\\\/blogs.bmj.com\\\/bmj\\\/author\\\/julietwalker\\\/\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"Covid-19 and vaccines\u2014known unknowns - The BMJ","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/","og_locale":"en_US","og_type":"article","og_title":"Covid-19 and vaccines\u2014known unknowns - The BMJ","og_description":"On 25 February 2021, The BMJ hosted a webinar on covid-19 vaccines. An expert panel discussed the safety and efficacy of the vaccines, as well as dose schedules and obstacles [...]More...","og_url":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/","og_site_name":"The BMJ","article_publisher":"https:\/\/www.facebook.com\/bmjdotcom\/","article_published_time":"2021-03-10T08:36:23+00:00","article_modified_time":"2021-03-22T10:01:45+00:00","og_image":[{"width":540,"height":350,"url":"https:\/\/blogs.bmj.com\/bmj\/files\/2021\/01\/coronavirus_pfizer_vaccine_PA-57616467.jpg","type":"image\/jpeg"}],"author":"julietwalker","twitter_card":"summary_large_image","twitter_creator":"@bmj_latest","twitter_site":"@bmj_latest","twitter_misc":{"Written by":"julietwalker","Est. reading time":"7 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"Article","@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#article","isPartOf":{"@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/"},"author":{"name":"julietwalker","@id":"https:\/\/blogs.bmj.com\/bmj\/#\/schema\/person\/373707d32533c2cbca204980b8cd3493"},"headline":"Covid-19 and vaccines\u2014known unknowns","datePublished":"2021-03-10T08:36:23+00:00","dateModified":"2021-03-22T10:01:45+00:00","mainEntityOfPage":{"@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/"},"wordCount":1586,"commentCount":0,"publisher":{"@id":"https:\/\/blogs.bmj.com\/bmj\/#organization"},"image":{"@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#primaryimage"},"thumbnailUrl":"https:\/\/blogs.bmj.com\/bmj\/files\/2021\/01\/coronavirus_pfizer_vaccine_PA-57616467.jpg","articleSection":["Covid-19 known unknowns webinars"],"inLanguage":"en-US","potentialAction":[{"@type":"CommentAction","name":"Comment","target":["https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#respond"]}]},{"@type":"WebPage","@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/","url":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/","name":"Covid-19 and vaccines\u2014known unknowns - The BMJ","isPartOf":{"@id":"https:\/\/blogs.bmj.com\/bmj\/#website"},"primaryImageOfPage":{"@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#primaryimage"},"image":{"@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#primaryimage"},"thumbnailUrl":"https:\/\/blogs.bmj.com\/bmj\/files\/2021\/01\/coronavirus_pfizer_vaccine_PA-57616467.jpg","datePublished":"2021-03-10T08:36:23+00:00","dateModified":"2021-03-22T10:01:45+00:00","breadcrumb":{"@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/"]}]},{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#primaryimage","url":"https:\/\/blogs.bmj.com\/bmj\/files\/2021\/01\/coronavirus_pfizer_vaccine_PA-57616467.jpg","contentUrl":"https:\/\/blogs.bmj.com\/bmj\/files\/2021\/01\/coronavirus_pfizer_vaccine_PA-57616467.jpg","width":540,"height":350,"caption":"Illustration shows a hand with a glove holding a dose of the vaccine at the vaccination of the staff members of the UZ Brussels University Hospital with the Covid-19 vaccine of Pfizer-BioNTech, in Jette, Brussels, Tuesday 19 January 2021. Members of the staff in contact with potentially coronavirus infected patients are the first to be vaccinated. BELGA PHOTO HATIM KAGHAT"},{"@type":"BreadcrumbList","@id":"https:\/\/blogs.bmj.com\/bmj\/2021\/03\/10\/covid-19-and-vaccines-known-unknowns\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/blogs.bmj.com\/bmj\/"},{"@type":"ListItem","position":2,"name":"Covid-19 and vaccines\u2014known unknowns"}]},{"@type":"WebSite","@id":"https:\/\/blogs.bmj.com\/bmj\/#website","url":"https:\/\/blogs.bmj.com\/bmj\/","name":"The BMJ","description":"Helping doctors make better decisions.","publisher":{"@id":"https:\/\/blogs.bmj.com\/bmj\/#organization"},"potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/blogs.bmj.com\/bmj\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"en-US"},{"@type":"Organization","@id":"https:\/\/blogs.bmj.com\/bmj\/#organization","name":"The BMJ","url":"https:\/\/blogs.bmj.com\/bmj\/","logo":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/blogs.bmj.com\/bmj\/#\/schema\/logo\/image\/","url":"https:\/\/blogs.bmj.com\/bmj\/files\/2018\/05\/The-BMJ-logo.jpg","contentUrl":"https:\/\/blogs.bmj.com\/bmj\/files\/2018\/05\/The-BMJ-logo.jpg","width":852,"height":568,"caption":"The BMJ"},"image":{"@id":"https:\/\/blogs.bmj.com\/bmj\/#\/schema\/logo\/image\/"},"sameAs":["https:\/\/www.facebook.com\/bmjdotcom\/","https:\/\/x.com\/bmj_latest"]},{"@type":"Person","@id":"https:\/\/blogs.bmj.com\/bmj\/#\/schema\/person\/373707d32533c2cbca204980b8cd3493","name":"julietwalker","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/secure.gravatar.com\/avatar\/34f10b717c81464cc7a2879c84cd30078f63b5a901e12905a02abd9d1ea9ec90?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/34f10b717c81464cc7a2879c84cd30078f63b5a901e12905a02abd9d1ea9ec90?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/34f10b717c81464cc7a2879c84cd30078f63b5a901e12905a02abd9d1ea9ec90?s=96&d=mm&r=g","caption":"julietwalker"},"url":"https:\/\/blogs.bmj.com\/bmj\/author\/julietwalker\/"}]}},"_links":{"self":[{"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/posts\/49775","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/users\/66"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/comments?post=49775"}],"version-history":[{"count":0,"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/posts\/49775\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/media\/49431"}],"wp:attachment":[{"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/media?parent=49775"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/categories?post=49775"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.bmj.com\/bmj\/wp-json\/wp\/v2\/tags?post=49775"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}