Covid-19 vaccine effectiveness against the omicron (B.1.1.529) variant

Andrews, Nick, Stowe, Julia, Kirsebom, Freja, Toffa, Samuel, Rickeard, Tim, Gallagher, Eileen, Gower, Charlotte, Kall, Meaghan, Groves, Natalie, O'Connell, Anne-Marie, Simons, David, Blomquist, Paula B., Zaidi, Asad, Nash, Sophie, Iwani Binti Abdul Aziz, Nurin, Thelwall, Simon, Dabrera, Gavin, Myers, Richard, Amirthalingam, Gayatri, Gharbia, Saheer, Barrett, Jeffrey C., Elson, Richard ORCID: https://orcid.org/0000-0001-6350-5274, Ladhani, Shamez N., Ferguson, Neil, Zambon, Maria, Campbell, Colin N. J., Brown, Kevin, Hopkins, Susan, Chand, Meera, Ramsay, Mary and Lopez Bernal, Jamie (2022) Covid-19 vaccine effectiveness against the omicron (B.1.1.529) variant. New England Journal of Medicine, 386 (16). pp. 1532-1546. ISSN 0028-4793

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Abstract

BACKGROUND: A rapid increase in coronavirus disease 2019 (Covid-19) cases due to the omicron (B.1.1.529) variant of severe acute respiratory syndrome coronavirus 2 in highly vaccinated populations has aroused concerns about the effectiveness of current vaccines. METHODS: We used a test-negative case-control design to estimate vaccine effectiveness against symptomatic disease caused by the omicron and delta (B.1.617.2) variants in England. Vaccine effectiveness was calculated after primary immunization with two doses of BNT162b2 (Pfizer-BioNTech), ChAdOx1 nCoV-19 (AstraZeneca), or mRNA-1273 (Moderna) vaccine and after a booster dose of BNT162b2, ChAdOx1 nCoV-19, or mRNA-1273. RESULTS: Between November 27, 2021, and January 12, 2022, a total of 886,774 eligible persons infected with the omicron variant, 204,154 eligible persons infected with the delta variant, and 1,572,621 eligible test-negative controls were identified. At all time points investigated and for all combinations of primary course and booster vaccines, vaccine effectiveness against symptomatic disease was higher for the delta variant than for the omicron variant. No effect against the omicron variant was noted from 20 weeks after two ChAdOx1 nCoV-19 doses, whereas vaccine effectiveness after two BNT162b2 doses was 65.5% (95% confidence interval [CI], 63.9 to 67.0) at 2 to 4 weeks, dropping to 8.8% (95% CI, 7.0 to 10.5) at 25 or more weeks. Among ChAdOx1 nCoV-19 primary course recipients, vaccine effectiveness increased to 62.4% (95% CI, 61.8 to 63.0) at 2 to 4 weeks after a BNT162b2 booster before decreasing to 39.6% (95% CI, 38.0 to 41.1) at 10 or more weeks. Among BNT162b2 primary course recipients, vaccine effectiveness increased to 67.2% (95% CI, 66.5 to 67.8) at 2 to 4 weeks after a BNT162b2 booster before declining to 45.7% (95% CI, 44.7 to 46.7) at 10 or more weeks. Vaccine effectiveness after a ChAdOx1 nCoV-19 primary course increased to 70.1% (95% CI, 69.5 to 70.7) at 2 to 4 weeks after an mRNA-1273 booster and decreased to 60.9% (95% CI, 59.7 to 62.1) at 5 to 9 weeks. After a BNT162b2 primary course, the mRNA-1273 booster increased vaccine effectiveness to 73.9% (95% CI, 73.1 to 74.6) at 2 to 4 weeks; vaccine effectiveness fell to 64.4% (95% CI, 62.6 to 66.1) at 5 to 9 weeks. CONCLUSIONS: Primary immunization with two doses of ChAdOx1 nCoV-19 or BNT162b2 vaccine provided limited protection against symptomatic disease caused by the omicron variant. A BNT162b2 or mRNA-1273 booster after either the ChAdOx1 nCoV-19 or BNT162b2 primary course substantially increased protection, but that protection waned over time. (Funded by the U.K. Health Security Agency.).

Item Type: Article
Uncontrolled Keywords: genetics *vaccine efficacy,sdg 3 - good health and well-being ,/dk/atira/pure/sustainabledevelopmentgoals/good_health_and_well_being
Faculty \ School: Faculty of Science > School of Environmental Sciences
Depositing User: LivePure Connector
Date Deposited: 01 Feb 2024 03:08
Last Modified: 01 Feb 2024 03:08
URI: https://ueaeprints.uea.ac.uk/id/eprint/94336
DOI: 10.1056/NEJMoa2119451

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