Journal article
Clinical severity of, and effectiveness of mRNA vaccines against, covid-19 from omicron, delta, and alpha SARS-CoV-2 variants in the United States: prospective observational study
BMJ (Online), Vol.376, pp.e069761-e069761
03/09/2022
DOI: 10.1136/bmj-2021-069761
PMCID: PMC8905308
PMID: 35264324
Abstract
AbstractObjectivesTo characterize the clinical severity of covid-19 associated with the alpha, delta, and omicron SARS-CoV-2 variants among adults admitted to hospital and to compare the effectiveness of mRNA vaccines to prevent hospital admissions related to each variant.DesignCase-control study.Setting21 hospitals across the United States.Participants11 690 adults (≥18 years) admitted to hospital: 5728 with covid-19 (cases) and 5962 without covid-19 (controls). Patients were classified into SARS-CoV-2 variant groups based on viral whole genome sequencing, and, if sequencing did not reveal a lineage, by the predominant circulating variant at the time of hospital admission: alpha (11 March to 3 July 2021), delta (4 July to 25 December 2021), and omicron (26 December 2021 to 14 January 2022).Main outcome measuresVaccine effectiveness calculated using a test negative design for mRNA vaccines to prevent covid-19 related hospital admissions by each variant (alpha, delta, omicron). Among patients admitted to hospital with covid-19, disease severity on the World Health Organization’s clinical progression scale was compared among variants using proportional odds regression.ResultsEffectiveness of the mRNA vaccines to prevent covid-19 associated hospital admissions was 85% (95% confidence interval 82% to 88%) for two vaccine doses against the alpha variant, 85% (83% to 87%) for two doses against the delta variant, 94% (92% to 95%) for three doses against the delta variant, 65% (51% to 75%) for two doses against the omicron variant; and 86% (77% to 91%) for three doses against the omicron variant. In-hospital mortality was 7.6% (81/1060) for alpha, 12.2% (461/3788) for delta, and 7.1% (40/565) for omicron. Among unvaccinated patients with covid-19 admitted to hospital, severity on the WHO clinical progression scale was higher for the delta versus alpha variant (adjusted proportional odds ratio 1.28, 95% confidence interval 1.11 to 1.46), and lower for the omicron versus delta variant (0.61, 0.49 to 0.77). Compared with unvaccinated patients, severity was lower for vaccinated patients for each variant, including alpha (adjusted proportional odds ratio 0.33, 0.23 to 0.49), delta (0.44, 0.37 to 0.51), and omicron (0.61, 0.44 to 0.85).ConclusionsmRNA vaccines were found to be highly effective in preventing covid-19 associated hospital admissions related to the alpha, delta, and omicron variants, but three vaccine doses were required to achieve protection against omicron similar to the protection that two doses provided against the delta and alpha variants. Among adults admitted to hospital with covid-19, the omicron variant was associated with less severe disease than the delta variant but still resulted in substantial morbidity and mortality. Vaccinated patients admitted to hospital with covid-19 had significantly lower disease severity than unvaccinated patients for all the variants.
Details
- Title: Subtitle
- Clinical severity of, and effectiveness of mRNA vaccines against, covid-19 from omicron, delta, and alpha SARS-CoV-2 variants in the United States: prospective observational study
- Creators
- Adam S Lauring - University of MichiganMark W Tenforde - Centers for Disease Control and PreventionJames D Chappell - Vanderbilt University Medical CenterManjusha Gaglani - Scott & White HospitalAdit A Ginde - University of Colorado DenverTresa McNeal - Scott & White HospitalShekhar Ghamande - Scott & White HospitalDavid J Douin - University of Colorado DenverH Keipp Talbot - Vanderbilt University Medical CenterJonathan D Casey - Vanderbilt University Medical CenterNicholas M Mohr - University of IowaAnne Zepeski - University of IowaNathan I Shapiro - Beth Israel Deaconess Medical CenterKevin W Gibbs - Wake Forest UniversityD Clark Files - Wake Forest UniversityDavid N Hager - Johns Hopkins MedicineArber Shehu - Johns Hopkins MedicineMatthew E Prekker - Hennepin County Medical CenterHeidi L Erickson - Hennepin County Medical CenterMatthew C Exline - The Ohio State UniversityMichelle N Gong - Albert Einstein College of MedicineAmira Mohamed - Albert Einstein College of MedicineNicholas J Johnson - University of WashingtonVasisht Srinivasan - University of WashingtonJay S Steingrub - Baystate Medical CenterIthan D Peltan - Intermountain Medical CenterSamuel M Brown - Intermountain Medical CenterEmily T Martin - University of MichiganArnold S Monto - University of MichiganAkram Khan - Department of Medicine, Oregon Health and Sciences University, Portland, OR, USACatherine L Hough - Department of Medicine, Oregon Health and Sciences University, Portland, OR, USALaurence W Busse - Emory UniversityCaitlin C ten Lohuis - Emory HealthcareAbhijit Duggal - Cleveland ClinicJennifer G Wilson - Stanford UniversityAlexandra June Gordon - Stanford UniversityNida Qadir - University of California, Los AngelesSteven Y Chang - University of California, Los AngelesChristopher Mallow - University of MiamiCarolina Rivas - University of MiamiHilary M Babcock - Washington University in St. LouisJennie H Kwon - Washington University in St. LouisNatasha Halasa - Vanderbilt University Medical CenterCarlos G Grijalva - Vanderbilt University Medical CenterTodd W Rice - Vanderbilt University Medical CenterWilliam B Stubblefield - Vanderbilt University Medical CenterAdrienne Baughman - Vanderbilt University Medical CenterKelsey N Womack - Vanderbilt University Medical CenterJillian P Rhoads - Vanderbilt University Medical CenterChristopher J Lindsell - Vanderbilt University Medical CenterKimberly W Hart - Vanderbilt University Medical CenterYuwei Zhu - Vanderbilt University Medical CenterKatherine Adams - Centers for Disease Control and PreventionStephanie J Schrag - Centers for Disease Control and PreventionSamantha M Olson - Centers for Disease Control and PreventionMiwako Kobayashi - Centers for Disease Control and PreventionJennifer R Verani - Centers for Disease Control and PreventionManish M Patel - Centers for Disease Control and PreventionWesley H Self - Vanderbilt University Medical CenterInfluenza and Other Viruses in the Acutely Ill (IVY) Network
- Resource Type
- Journal article
- Publication Details
- BMJ (Online), Vol.376, pp.e069761-e069761
- DOI
- 10.1136/bmj-2021-069761
- PMID
- 35264324
- PMCID
- PMC8905308
- NLM abbreviation
- BMJ
- ISSN
- 0959-535X
- eISSN
- 1756-1833
- Publisher
- British Medical Journal Publishing Group
- Language
- English
- Date published
- 03/09/2022
- Academic Unit
- Epidemiology; Emergency Medicine; Anesthesia; Injury Prevention Research Center
- Record Identifier
- 9984296147102771
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