{"doi":"10.1056/nejmoa2113017","title":"Efficacy of the mRNA-1273 SARS-CoV-2 Vaccine at Completion of Blinded Phase","abstract":"BACKGROUND: At interim analysis in a phase 3, observer-blinded, placebo-controlled clinical trial, the mRNA-1273 vaccine showed 94.1% efficacy in preventing coronavirus disease 2019 (Covid-19). After emergency use of the vaccine was authorized, the protocol was amended to include an open-label phase. Final analyses of efficacy and safety data from the blinded phase of the trial are reported. METHODS: We enrolled volunteers who were at high risk for Covid-19 or its complications; participants were randomly assigned in a 1:1 ratio to receive two intramuscular injections of mRNA-1273 (100 μg) or placebo, 28 days apart, at 99 centers across the United States. The primary end point was prevention of Covid-19 illness with onset at least 14 days after the second injection in participants who had not previously been infected with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The data cutoff date was March 26, 2021. RESULTS: The trial enrolled 30,415 participants; 15,209 were assigned to receive the mRNA-1273 vaccine, and 15,206 to receive placebo. More than 96% of participants received both injections, 2.3% had evidence of SARS-CoV-2 infection at baseline, and the median follow-up was 5.3 months in the blinded phase. Vaccine efficacy in preventing Covid-19 illness was 93.2% (95% confidence interval [CI], 91.0 to 94.8), with 55 confirmed cases in the mRNA-1273 group (9.6 per 1000 person-years; 95% CI, 7.2 to 12.5) and 744 in the placebo group (136.6 per 1000 person-years; 95% CI, 127.0 to 146.8). The efficacy in preventing severe disease was 98.2% (95% CI, 92.8 to 99.6), with 2 cases in the mRNA-1273 group and 106 in the placebo group, and the efficacy in preventing asymptomatic infection starting 14 days after the second injection was 63.0% (95% CI, 56.6 to 68.5), with 214 cases in the mRNA-1273 group and 498 in the placebo group. Vaccine efficacy was consistent across ethnic and racial groups, age groups, and participants with coexisting conditions. No safety concerns were identified. CONCLUSIONS: The mRNA-1273 vaccine continued to be efficacious in preventing Covid-19 illness and severe disease at more than 5 months, with an acceptable safety profile, and protection against asymptomatic infection was observed. (Funded by the Biomedical Advanced Research and Development Authority and the National Institute of Allergy and Infectious Diseases; COVE ClinicalTrials.gov number, NCT04470427.).","journal":"New England Journal of Medicine","year":2021,"id":145183,"datarank":8.311536810567464,"base_score":6.4967749901858625,"endowment":6.4967749901858625,"self_citation_contribution":0.9745162485278795,"citation_network_contribution":7.337020562039585,"self_endowment_contribution":0.9745162485278795,"citer_contribution":7.337020562039585,"corpus_percentile":null,"corpus_rank":null,"citation_count":662,"citer_count":100,"citers_with_citation_signal":100,"citers_with_endowment":100,"datacite_reuse_total":0,"is_dataset":false,"is_dataset_confidence":0.8481,"is_data_producer":true,"deposit_databanks":{"ClinicalTrials.gov":["NCT04470427"]},"is_oa":true,"file_count":0,"downloads":0,"has_version_chain":false,"published_date":"2021-01-01","fair_score":null,"fair_percentile":null,"algorithm_id":"datarank_citation_only_1hop_v6","ranking_scope":"data_only","authors":[{"id":3841,"name":"Lindsey R. 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Fichtenbaum","orcid":"0000-0002-6778-7253","position":9,"is_corresponding":false},{"id":486262,"name":"Marcus Zervos","orcid":"0000-0002-7328-4898","position":10,"is_corresponding":false},{"id":616918,"name":"Bruce Rankin","orcid":null,"position":11,"is_corresponding":false},{"id":616919,"name":"Frank Eder","orcid":null,"position":12,"is_corresponding":false},{"id":615314,"name":"Gregory Feldman","orcid":"0000-0001-6145-125X","position":13,"is_corresponding":false},{"id":616920,"name":"C Kennelly","orcid":null,"position":14,"is_corresponding":false},{"id":616921,"name":"Laurie J. Han-Conrad","orcid":null,"position":15,"is_corresponding":false},{"id":615315,"name":"Michael Levin","orcid":"0000-0003-2439-7981","position":16,"is_corresponding":false},{"id":38212,"name":"Kathleen M. 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