TY - JOUR
AU - Hulme, William
AU - Williamson, Elizabeth J.
AU - Green, Amelia C.A.
AU - Bhaskaran, Krishnan
AU - McDonald, Helen I.
AU - Rentsch, Christopher T.
AU - Schultze, Anna
AU - Tazare, John
AU - Curtis, Helen J.
AU - Walker, Alex J.
AU - Tomlinson, Laurie A.
AU - Palmer, Tom
AU - Horne, Elsie M.F.
AU - Mackenna, Brian
AU - Morton, Caroline E.
AU - Mehrkar, Amir
AU - Morley, Jessica
AU - Fisher, Louis
AU - Bacon, Sebastian C.J.
AU - Evans, David
AU - Inglesby, Peter
AU - Hickman, George
AU - Davy, Simon
AU - Ward, Tom
AU - Croker, Richard
AU - Eggo, Rosalind M.
AU - Wong, Angel Y.S.
AU - Mathur, Rohini
AU - Wing, Kevin
AU - Forbes, Harriet
AU - Grint, Daniel J.
AU - Douglas, Ian J.
AU - Evans, Stephen J.W.
AU - Smeeth, Liam
AU - Bates, Chris J.
AU - Cockburn, Jonathan
AU - Parry, John
AU - Hester, Frank
AU - Harper, Sam
AU - Sterne, Jonathan A.C.
AU - Hernán, Miguel A.
AU - Goldacre, Ben
PY - 2022
DA - July
TI - Comparative effectiveness of ChAdOx1 versus BNT162b2 covid-19 vaccines in health and social care workers in England: cohort study using OpenSAFELY
JO - The BMJ
VL - 378
DO - https://doi.org/10.1136/bmj-2021-068946
AB - Objective: To compare the effectiveness of the BNT162b2 mRNA (Pfizer-BioNTech) and the ChAdOx1 (Oxford-AstraZeneca) covid-19 vaccines against infection and covid-19 disease in health and social care workers. Design: Cohort study, emulating a comparative effectiveness trial, on behalf of NHS England. Setting: Linked primary care, hospital, and covid-19 surveillance records available within the OpenSAFELY-TPP research platform, covering a period when the SARS-CoV-2 Alpha variant was dominant. Participants: 317 341 health and social care workers vaccinated between 4 January and 28 February 2021, registered with a general practice using the TPP SystmOne clinical information system in England, and not clinically extremely vulnerable. Interventions: Vaccination with either BNT162b2 or ChAdOx1 administered as part of the national covid-19 vaccine roll-out. Main outcome measures: Recorded SARS-CoV-2 positive test, or covid-19 related attendance at an accident and emergency (A&amp;E) department or hospital admission occurring within 20 weeks of receipt of the first vaccine dose. Results: Over the duration of 118 771 person-years of follow-up there were 6962 positive SARS-CoV-2 tests, 282 covid-19 related A&amp;E attendances, and 166 covid-19 related hospital admissions. The cumulative incidence of each outcome was similar for both vaccines during the first 20 weeks after vaccination. The cumulative incidence of recorded SARS-CoV-2 infection 20 weeks after first-dose vaccination with BNT162b2 was 21.7 per 1000 people (95% confidence interval 20.9 to 22.4) and with ChAdOx1 was 23.7 (21.8 to 25.6), representing a difference of 2.04 per 1000 people (0.04 to 4.04). The difference in the cumulative incidence per 1000 people of covid-19 related A&amp;E attendance at 20 weeks was 0.06 per 1000 people (95% CI-0.31 to 0.43). For covid-19 related hospital admission, this difference was 0.11 per 1000 people (-0.22 to 0.44). Conclusions: In this cohort of healthcare workers where we would not anticipate vaccine type to be related to health status, we found no substantial differences in the incidence of SARS-CoV-2 infection or covid-19 disease up to 20 weeks after vaccination. Incidence dropped sharply at 3-4 weeks after vaccination, and there were few covid-19 related hospital attendance and admission events after this period. This is in line with expected onset of vaccine induced immunity and suggests strong protection against Alpha variant covid-19 disease for both vaccines in this relatively young and healthy population of healthcare workers.
PB - BMJ Publishing Group
UR - https://www.research.ed.ac.uk/en/publications/b63d8768-f4f3-4815-a250-d487b5b66e5b
KW - Coronavirus (COVID-19)
KW - Immunisation and screening
KW - Work and workforce
ER