{"id":2625,"date":"2020-12-08T12:19:22","date_gmt":"2020-12-08T20:19:22","guid":{"rendered":"https:\/\/depts.washington.edu\/pandemicalliance\/?p=2625"},"modified":"2020-12-09T12:20:46","modified_gmt":"2020-12-09T20:20:46","slug":"safety-and-efficacy-of-the-chadox1-ncov-19-vaccine-azd1222-against-sars-cov-2-an-interim-analysis-of-four-randomised-controlled-trials-in-brazil-south-africa-and-the-uk","status":"publish","type":"post","link":"https:\/\/depts.washington.edu\/pandemicalliance\/2020\/12\/08\/safety-and-efficacy-of-the-chadox1-ncov-19-vaccine-azd1222-against-sars-cov-2-an-interim-analysis-of-four-randomised-controlled-trials-in-brazil-south-africa-and-the-uk\/","title":{"rendered":"Safety and Efficacy of the ChAdOx1 NCoV-19 Vaccine (AZD1222) against SARS-CoV-2: An Interim Analysis of Four Randomised Controlled Trials in Brazil, South Africa, and the UK"},"content":{"rendered":"<p>An interim analysis of two of the four ongoing phase 2\/3 trials for the Oxford\u2013AstraZeneca chimpanzee adenovirus vectored vaccine ChAdOx1 nCoV-19 (n=7,548 in UK trial, n=4,088 in Brazil trial) showed a vaccine efficacy of 62.1% (95%CI 41.0-75.7%) among participants who received the planned two standard doses (27 COVID-19 cases among 4,440 in the vaccine group and 71 COVID-19 cases among 4,455 in the placebo group).<span class=\"Apple-converted-space\">\u00a0<\/span><\/p>\n<p>A smaller number of participants (n=1367 in the vaccine group and 1374 in the placebo group) erroneously received a low initial dose followed by a standard second dose. The observed vaccine efficacy for the low-dose\/standard dose combination was 90.0% (95% CI 67.4-97.0) (3 of 1,367 in the vaccine group vs 30 of 1,374 in the placebo group). All of the participants who received the low-dose\/standard dose combination were age 18-55, while 16% of those that received two standard doses were &gt;55 years old.<\/p>\n<p>The overall vaccine efficacy against symptomatic COVID-19 was 70.4% (95.8% CI 54.8-80.6%), with no COVID-19-related hospital admissions occurring in vaccine recipients and 10 occurring in the control group at least 14 days after the second dose.<\/p>\n<p>The majority of participants included in this interim analysis were aged 18-55 (88%), white (83%), and female (61%)<\/p>\n<p><i>Voysey et al. (Dec 8, 2020). Safety and Efficacy of the ChAdOx1 NCoV-19 Vaccine (AZD1222) against SARS-CoV-2: An Interim Analysis of Four Randomised Controlled Trials in Brazil, South Africa, and the UK. The Lancet. <\/i><a href=\"https:\/\/doi.org\/10.1016\/S0140-6736(20)32661-1\">https:\/\/doi.org\/10.1016\/S0140-6736(20)32661-1<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>An interim analysis of two of the four ongoing phase 2\/3 trials for the Oxford\u2013AstraZeneca chimpanzee adenovirus vectored vaccine ChAdOx1 nCoV-19 (n=7,548 in UK trial, n=4,088 in Brazil trial) showed a vaccine efficacy of 62.1% (95%CI 41.0-75.7%) among participants who received the planned two standard doses (27 COVID-19 cases among 4,440 in the vaccine group&#8230;<\/p>\n<div><a class=\"more\" href=\"https:\/\/depts.washington.edu\/pandemicalliance\/2020\/12\/08\/safety-and-efficacy-of-the-chadox1-ncov-19-vaccine-azd1222-against-sars-cov-2-an-interim-analysis-of-four-randomised-controlled-trials-in-brazil-south-africa-and-the-uk\/\">Read more<\/a><\/div>\n","protected":false},"author":7,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_links_to":"","_links_to_target":""},"categories":[6],"tags":[33],"topic":[31],"class_list":["post-2625","post","type-post","status-publish","format-standard","hentry","category-article-summary","tag-vaccines","topic-vaccines-and-immunity"],"_links":{"self":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts\/2625","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/users\/7"}],"replies":[{"embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/comments?post=2625"}],"version-history":[{"count":1,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts\/2625\/revisions"}],"predecessor-version":[{"id":2626,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/posts\/2625\/revisions\/2626"}],"wp:attachment":[{"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/media?parent=2625"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/categories?post=2625"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/tags?post=2625"},{"taxonomy":"topic","embeddable":true,"href":"https:\/\/depts.washington.edu\/pandemicalliance\/wp-json\/wp\/v2\/topic?post=2625"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}