Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant

Bibliographic Data

ID23346473
AuthorsNick Andrews (0000-0003-4388-1832, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Julia Stowe (0000-0002-3999-6461, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Freja Kirsebom (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Samuel Toffa (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Tim Rickeard (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Eileen Gallagher (0009-0007-9223-5542, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Charlotte Gower (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Meaghan Kall (0000-0001-6971-427X, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Natalie Groves (0000-0002-3832-3484, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Anne-Marie O’Connell (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), David Simons (0000-0001-9655-1656, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Paula B Blomquist (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Asad Zaidi (0000-0002-5250-9576, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Sophie Nash (0000-0002-7717-6982, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Nurin Iwani Binti Abdul Aziz (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Simon Thelwall (0000-0002-0434-2724, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Gavin Dabrera (0000-0003-4606-5945, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Richard Myers (0000-0003-4269-1164, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Gayatri Amirthalingam (0000-0003-2078-0975, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Saheer Gharbia (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Jeffrey C Barrett (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Richard Elson (0000-0001-6350-5274, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Shamez N Ladhani (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Neil Ferguson (0000-0001-8361-2595, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Maria Zambon (0000-0002-8897-7881, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Colin N J Campbell (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Kevin Brown (0000-0002-3238-3750, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Shakita Hopkins (0000-0001-5179-5702, Anna Needs Neuroblastoma Answers), Susan Hopkins (0000-0003-1781-2382, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Meera Chand (0000-0001-9697-0340, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Mary Ramsay (From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un), Jamie Lopez Bernal (0000-0002-1301-5653, From the U.K. Health Security Agency (N.A., J.S., F.K., S. Toffa, T.R., E.G., C.G., M.K., N.G., A.-M.O., D.S., P.B.B., A.Z., S.N., N.I.B.A.A., S. Thelwall, G.D., R.M., G.A., S.G., R.E., S.N.L., M.Z., C.N.J.C., K.B., S.H., M.C., M.R., J.L.B.), the National Institute for Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (N.A., G.A., C.N.J.C., K.B., M.R., J.L.B.), the Paediatric Infectious Diseases Research Group, St. George’s Un)
Year2022
Volume386
Issue16
Pages1532-1546
Publication date2022-04-21
Peer ReviewedYes
Open AccessNo
TypeARTICLE
VenueNew England Journal of Medicine (JOURNAL)
Journal identifiersISSN: 0028-4793 • E-ISSN: 1533-4406
PublisherMassachusetts Medical Society (PUBLISHER • US)
DOI10.1056/nejmoa2119451
PMID35249272
OpenAlexW4214863616
LanguageEN
Citations received72
References cited24

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.).

Booster (rocketry) · Disease · Immunization · Infectious disease (medical specialty) · Vaccination · Respiratory viral infections research · SARS-CoV-2 and COVID-19 Research · Vaccine Coverage and Hesitancy