CoChat
Sign Up
Cited by 794SARS-CoV-2 and COVID-19 ResearchVaccine Coverage and HesitancyCOVID-19 epidemiological studies

The DOI matches its Crossref record; 24 of the 27 references it cites were found in a registry or an index, and 1 are not checked yet; none of the 19 sources its claims cite is checked for support yet.

COVID-19 vaccine coverage in health-care workers in England and effectiveness of BNT162b2 mRNA vaccine against infection (SIREN): a prospective, multicentre, cohort study

Open access
Hall, Victoria Jane, Foulkes, Sarah, Saei, Ayoub, Andrews, Nick, Oguti, Blanche, Charlett, Andre, Wellington, Edgar, Stowe, Julia, Gillson, Natalie, Atti, Ana, Islam, Jasmin, Karagiannis, Ioannis, Munro, Katie, Khawam, Jameel, Chand, Meera A, Brown, Colin S, Ramsay, Mary, Lopez-Bernal, Jamie, Hopkins, Susan, Andrews, N, Atti, A, Aziz, H, Brooks, T, Brown, CS, Camero, D, Carr, C, Chand, MA, Charlett, A, Crawford, H, Cole, M, Conneely, J, D'Arcangelo, S, Ellis, J, Evans, S, Foulkes, S, Gillson, N, Gopal, R, Hall, L, Hall, VJ, Harrington, P, Hopkins, S, Hewson, J, Hoschler, K, Ironmonger, D, Islam, J, Kall, M, Karagiannis, I, Kay, O, Khawam, J, King, E, Kirwan, P, Kyffin, R, Lackenby, A, Lattimore, M, Linley, E, Lopez-Bernal, J, Mabey, L, McGregor, R, Miah, S, Monk, EJM, Munro, K, Naheed, Z, Nissr, A, O'Connell, AM, Oguti, B, Okafor, H, Organ, S, Osbourne, J, Otter, A, Patel, M, Platt, S, Pople, D, Potts, K, Ramsay, M, Robotham, J, Rokadiya, S, Rowe, C, Saei, A, Sebbage, G, Semper, A, Shrotri, M, Simmons, R, Soriano, A, Staves, P, Taylor, S, Taylor, A, Tengbe, A, Tonge, S, Vusirikala, A, Wallace, S, Wellington, E, Zambon, M, Corrigan, D, Sartaj, M, Cromey, L, Campbell, S, Braithwaite, K, Price, L, Haahr, L, Stewart, S, Lacey, ED, Partridge, L, Stevens, G, Ellis, Y, Hodgson, H, Norman, C, Lacey, ED, Larru, B, Mcwilliam, S, Roynon, A, Northfield, J, Winchester, S, Cieciwa, P, Pai, A, Bakker, P, Loughrey, C, Watt, A, Adair, F, Hawkins, A, Grant, A, Temple-Purcell, R, Howard, J, Slawson, N, Subudhi, C, Davies, S, Bexley, A, Penn, R, Wong, N, Boyd, G, Rajgopal, A, Arenas-Pinto, A, Matthews, R, Whileman, A, Laugharne, R, Ledger, J, Barnes,, T, Jones, C, Osuji, N, Chitalia, N, Bailey, T, Akhtar, S, Harrison, G, Horne, S, Walker, N, Agwuh, K, Maxwell, V, Graves, J, Williams, S, O'Kelly, A, Ridley, P, Cowley, A, Johnstone, H, Swift, P, Democratis, J, Meda, M, Brake, S, Gunn, J, Selassi, A, Hams, S, Irvine, V, Chandrasekaran, B, Forsyth, C, Radmore, J, Thomas, C, Brown, K, Roberts, S, Burns, P, Gajee, K, Lewis, T, Byrne, TM, Sanderson, F, Knight, S, Macnaughton, E, Burton, BJL, Smith, H, Chaudhuri, R, Aeron-Thomas, J, Hollinshead, K, Shorten, RJ, Swan, A, Shorten, RJ, Favager, C, Murira, J, Baillon, S, Hamer, S, Shah, A, Russell, J, Brennan, D, Dave, A, Chawla, A, Westwell, F, Adeboyeku, D, Papineni, P, Pegg, C, Williams, M, Ahmad, S, Horsley, A, Gabriel, C, Pagget, K, Cieciwa, P, Maloney, G, Ashcroft, J, Del Rosario, I, Crosby-Nwaobi, R, Flanagan, D, Dhasmana, D, Fowler, S, Cameron, E, Prentice, L, Sinclair, C, Irvine, V, Bateman, V, McLelland-Brooks, K, Ho, A, Murphy, M, Cochrane, A, Gibson, A, Patel, M, Black, K, Tempeton, K, Donaldson, S, Coke, L, Elumogo, N, Elliott, J, Padgett, D, Cross, A, Mirfenderesky, M, Joyce, S, Sinanovic, I, Howard, M, Lewis, T, Cowling, P, Brazil, M, Hanna, E, Abdelrazik, A, Brand, S, Sheridan, EA, Wadams, B, Lloyd, A, Mouland, J, Giles, J, Pottinger, G, Coles, H, Joseph, M, Lee, M, Orr, S, Chenoweth, H, Browne, D, Auckland, C, Lear, R, Mahungu, T, Rodger, A, Warren, S, Brooking, D, Pai, S, Druyeh, R, Smith, E, Stone, S, Meisner, S, Delgado, D, Underhill, E, Keen, L, Aga, M, Domingos, P, Gormley, S, Kerrison, C, Birch, S, DeSilva, T, Allsop, L, Ambalkar, S, Beekes, M, Jose, S, Tomlinson, J, Painter, Sharen, Price, C, Pepperell, J, James, K, Trinick, T, Moore, L, Day, J, Boulos, A, Knox, I, Defever, E, McCracken, D, Brown, K, Gray, K, Houston, A, Planche, T, Pritchard Jones, R, Wycherley, Diane, Bennett, S, Marrs, J, Nimako, K, Stewart, B, Bain, SC, Kalakonda, N, Khanduri, S, Ashby, A, Holden, M, Mahabir, N, Harwood, J, Payne, B, Court, K, White, N, Longfellow, R, Hughes, LE, Green, ME, Halkes, M, Mercer, P, Roebuck, A, Wilson-Davies, E, Gallego, L, Lazarus, R, Aldridge, N, Berry, L, Game, F, Reynolds, T, Holmes, C, Wiselka, M, Higham, A, Booth, M, Duff, C, Alderton, J, Hilton, D, Powell, J, Jackson, A, Plant, AJ, Ahmed, N, Chin, T, Qazzafi, MZ, Moody, AM, Tilley, RE, Donaghy, T, O'Kane, M, Shipman, K, Sierra, R, Parmar, C, Mills, G, Harvey, D, Huang, YWJ, Birch, J, Robinson, L, Board, S, Broadley, A, Laven, C, Todd, N, Eyre, DW, Jeffery, K, Dunachie, S, Duncan, C, Klenerman, P, Turtle, L, Baxendale, H, Heeney, JL·2021·The Lancet
DOI 10.1016/s0140-6736(21)00790-xPMC PMC8064668
Open this paper in CoChat — free accountOpen PDF

Abstract

Background BNT162b2 mRNA and ChAdOx1 nCOV-19 adenoviral vector vaccines have been rapidly rolled out in the UK from December, 2020. We aimed to determine the factors associated with vaccine coverage for both vaccines and documented the vaccine effectiveness of the BNT162b2 mRNA vaccine in a cohort of health-care workers undergoing regular asymptomatic testing. Methods The SIREN study is a prospective cohort study among staff (aged ≥18 years) working in publicly-funded hospitals in the UK. Participants were assigned into either the positive cohort (antibody positive or history of infection [indicated by previous positivity of antibody or PCR tests]) or the negative cohort (antibody negative with no previous positive test) at the beginning of the follow-up period. Baseline risk factors were collected at enrolment, symptom status was collected every 2 weeks, and vaccination status was collected through linkage to the National Immunisations Management System and questionnaires. Participants had fortnightly asymptomatic SARS-CoV-2 PCR testing and monthly antibody testing, and all tests (including symptomatic testing) outside SIREN were captured. Data cutoff for this analysis was Feb 5, 2021. The follow-up period was Dec 7, 2020, to Feb 5, 2021. The primary outcomes were vaccinated participants (binary ever vacinated variable; indicated by at least one vaccine dose recorded by at least one of the two vaccination data sources) for the vaccine coverage analysis and SARS-CoV-2 infection confirmed by a PCR test for the vaccine effectiveness analysis. We did a mixed-effect logistic regression analysis to identify factors associated with vaccine coverage. We used a piecewise exponential hazard mixed-effects model (shared frailty-type model) using a Poisson distribution to calculate hazard ratios to compare time-to-infection in unvaccinated and vaccinated participants and estimate the impact of the BNT162b2 vaccine on all PCR-positive infections (asymptomatic and symptomatic). This study is registered with ISRCTN, number ISRCTN11041050, and is ongoing. Findings 23 324 participants from 104 sites (all in England) met the inclusion criteria for this analysis and were enrolled. Included participants had a median age of 46·1 years (IQR 36·0-54·1) and 19 692 (84%) were female; 8203 (35%) were assigned to the positive cohort at the start of the analysis period, and 15 121 (65%) assigned to the negative cohort. Total follow-up time was 2 calendar months and 1 106 905 person-days (396 318 vaccinated and 710 587 unvaccinated). Vaccine coverage was 89% on Feb 5, 2021, 94% of whom had BNT162b2 vaccine. Significantly lower coverage was associated with previous infection, gender, age, ethnicity, job role, and Index of Multiple Deprivation score. During follow-up, there were 977 new infections in the unvaccinated cohort, an incidence density of 14 infections per 10 000 person-days; the vaccinated cohort had 71 new infections 21 days or more after their first dose (incidence density of eight infections per 10 000 person-days) and nine infections 7 days after the second dose (incidence density four infections per 10 000 person-days). In the unvaccinated cohort, 543 (56%) participants had typical COVID-19 symptoms and 140 (14%) were asymptomatic on or 14 days before their PCR positive test date, compared with 29 (36%) with typical COVID-19 symptoms and 15 (19%) asymptomatic in the vaccinated cohort. A single dose of BNT162b2 vaccine showed vaccine effectiveness of 70% (95% CI 55-85) 21 days after first dose and 85% (74-96) 7 days after two doses in the study population. Interpretation Our findings show that the BNT162b2 vaccine can prevent both symptomatic and asymptomatic infection in working-age adults. This cohort was vaccinated when the dominant variant in circulation was B1.1.7 and shows effectiveness against this variant. Funding Public Health England, UK Department of Health and Social Care, and the National Institute for Health Research.

Checked 2026-10-06 · 1 reference not checked yet

Overview

Integrity signals

Registry

Crossref · 10.1016/s0140-6736(21)00790-x

Cites

24 of 25 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

40 Own result · 20 Own method · 12 Not checked yet · 7 Own interpretation · 1 No basis given

Verify all 16 references — free account

Show all 52 claims

  • It may state two separate claims as one. 18
  • Probably not a substantial claim. 11
28 of 28

  • The authors state this as an assumption.

    The proportional hazards assumption holds in the piecewise exponential hazard model.

    “The proportional hazards in this model is an assumption.”

  • The authors state this as an assumption.

    The hospital trust random effect is normally distributed.

    “The hospital trust random effect was assumed to be normal, and this implies that frailty (exp(hospital trusts)) distribution was log-normal.”

  • The paper relies on this without support.

    The dominant SARS-CoV-2 variant in circulation during the study period was B1.1.7.

    “This cohort was vaccinated when the dominant variant in circulation was B1.1.7 and shows effectiveness against this variant.”

  • The paper relies on this without support.

    An immunological response to the vaccine dose is provoked by 21 days after the first dose and 7 days after the second dose.

    “We calculated hazard ratios from 21 days after first dose and 7 days after second dose using a weighted average method, the point at which an immunological response to the vaccine dose should have been provoked.”

  • The paper relies on this without support.

    At the time of the study, there was a scarcity of published research on whether vaccination reduces asymptomatic infection or transmission worldwide.

    “To date, little has been published on the effect of vaccination on reducing asymptomatic infection or transmission globally.”
5 of 5

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Citations

Cites

Show all 27 references

Research works printed but not linked: 1

  1. MacKenna, 2021, Trends, regional variation, and clinical characteristics of COVID-19 vaccine recipients: a retrospective cohort study in 23·4 million patients using OpenSAFELY, medRxiv

Cited by

Sorted by citations

Items 501–600 of 794

Related

See all

Metadata

Authors
Hall, V. J., Foulkes, S., Saei, A., Andrews, N., Oguti, B., Charlett, A., Wellington, E., Stowe, J., Gillson, N., Atti, A., Islam, J., Karagiannis, I., Munro, K., Khawam, J., Chand, M. A., Brown, C. S., Ramsay, M., Lopez-Bernal, J., Hopkins, S., Andrews, N., Atti, A., Aziz, H., Brooks, T., Brown, C., Camero, D., Carr, C., Chand, M., Charlett, A., Crawford, H., Cole, M., Conneely, J., D'Arcangelo, S., Ellis, J., Evans, S., Foulkes, S., Gillson, N., Gopal, R., Hall, L., Hall, V., Harrington, P., Hopkins, S., Hewson, J., Hoschler, K., Ironmonger, D., Islam, J., Kall, M., Karagiannis, I., Kay, O., Khawam, J., King, E., Kirwan, P., Kyffin, R., Lackenby, A., Lattimore, M., Linley, E., Lopez-Bernal, J., Mabey, L., McGregor, R., Miah, S., Monk, E., Munro, K., Naheed, Z., Nissr, A., O'Connell, A., Oguti, B., Okafor, H., Organ, S., Osbourne, J., Otter, A., Patel, M., Platt, S., Pople, D., Potts, K., Ramsay, M., Robotham, J., Rokadiya, S., Rowe, C., Saei, A., Sebbage, G., Semper, A., Shrotri, M., Simmons, R., Soriano, A., Staves, P., Taylor, S., Taylor, A., Tengbe, A., Tonge, S., Vusirikala, A., Wallace, S., Wellington, E., Zambon, M., Corrigan, D., Sartaj, M., Cromey, L., Campbell, S., Braithwaite, K., Price, L., Haahr, L., Stewart, S., Lacey, E., Partridge, L., Stevens, G., Ellis, Y., Hodgson, H., Norman, C., Lacey, E., Larru, B., Mcwilliam, S., Roynon, A., Northfield, J., Winchester, S., Cieciwa, P., Pai, A., Bakker, P., Loughrey, C., Watt, A., Adair, F., Hawkins, A., Grant, A., Temple-Purcell, R., Howard, J., Slawson, N., Subudhi, C., Davies, S., Bexley, A., Penn, R., Wong, N., Boyd, G., Rajgopal, A., Arenas-Pinto, A., Matthews, R., Whileman, A., Laugharne, R., Ledger, J., Barnes, Jones, C., Osuji, N., Chitalia, N., Bailey, T., Akhtar, S., Harrison, G., Horne, S., Walker, N., Agwuh, K., Maxwell, V, Graves, J., Williams, S., O'Kelly, A., Ridley, P., Cowley, A., Johnstone, H., Swift, P., Democratis, J., Meda, M., Brake, S., Gunn, J., Selassi, A., Hams, S., Irvine, V, Chandrasekaran, B., Forsyth, C., Radmore, J., Thomas, C., Brown, K., Roberts, S., Burns, P., Gajee, K., Lewis, T., Byrne, T., Sanderson, F., Knight, S., Macnaughton, E., Burton, B., Smith, H., Chaudhuri, R., Aeron-Thomas, J., Hollinshead, K., Shorten, R., Swan, A., Shorten, R., Favager, C., Murira, J., Baillon, S., Hamer, S., Shah, A., Russell, J., Brennan, D., Dave, A., Chawla, A., Westwell, F., Adeboyeku, D., Papineni, P., Pegg, C., Williams, M., Ahmad, S., Horsley, A., Gabriel, C., Pagget, K., Cieciwa, P., Maloney, G., Ashcroft, J., Del Rosario, I., Crosby-Nwaobi, R., Flanagan, D., Dhasmana, D., Fowler, S., Cameron, E., Prentice, L., Sinclair, C., Irvine, V, Bateman, V, McLelland-Brooks, K., Ho, A., Murphy, M., Cochrane, A., Gibson, A., Patel, M., Black, K., Tempeton, K., Donaldson, S., Coke, L., Elumogo, N., Elliott, J., Padgett, D., Cross, A., Mirfenderesky, M., Joyce, S., Sinanovic, I., Howard, M., Lewis, T., Cowling, P., Brazil, M., Hanna, E., Abdelrazik, A., Brand, S., Sheridan, E., Wadams, B., Lloyd, A., Mouland, J., Giles, J., Pottinger, G., Coles, H., Joseph, M., Lee, M., Orr, S., Chenoweth, H., Browne, D., Auckland, C., Lear, R., Mahungu, T., Rodger, A., Warren, S., Brooking, D., Pai, S., Druyeh, R., Smith, E., Stone, S., Meisner, S., Delgado, D., Underhill, E., Keen, L., Aga, M., Domingos, P., Gormley, S., Kerrison, C., Birch, S., DeSilva, T., Allsop, L., Ambalkar, S., Beekes, M., Jose, S., Tomlinson, J., Painter, S., Price, C., Pepperell, J., James, K., Trinick, T., Moore, L., Day, J., Boulos, A., Knox, I., Defever, E., McCracken, D., Brown, K., Gray, K., Houston, A., Planche, T., Pritchard Jones, R., Wycherley, D., Bennett, S., Marrs, J., Nimako, K., Stewart, B., Bain, S., Kalakonda, N., Khanduri, S., Ashby, A., Holden, M., Mahabir, N., Harwood, J., Payne, B., Court, K., White, N., Longfellow, R., Hughes, L., Green, M., Halkes, M., Mercer, P., Roebuck, A., Wilson-Davies, E., Gallego, L., Lazarus, R., Aldridge, N., Berry, L., Game, F., Reynolds, T., Holmes, C., Wiselka, M., Higham, A., Booth, M., Duff, C., Alderton, J., Hilton, D., Powell, J., Jackson, A., Plant, A., Ahmed, N., Chin, T., Qazzafi, M., Moody, A., Tilley, R., Donaghy, T., O'Kane, M., Shipman, K., Sierra, R., Parmar, C., Mills, G., Harvey, D., Huang, Y., Birch, J., Robinson, L., Board, S., Broadley, A., Laven, C., Todd, N., Eyre, D., Jeffery, K., Dunachie, S., Duncan, C., Klenerman, P., Turtle, L., Baxendale, H., & Heeney, J.
Affiliations
  • Public Health England (GB)
  • St Thomas' Hospital (GB)
  • Guy's Hospital (GB)
Corresponding author
  • Aziz, H
  • Carr, C
  • Crawford, H
  • Okafor, H
  • Potts, K
  • Rowe, C
  • Braithwaite, K
  • Hodgson, H
  • Norman, C
  • Loughrey, C
  • Adair, F
  • Subudhi, C
  • Jones, C
  • Agwuh, K
  • Johnstone, H
  • Forsyth, C
  • Thomas, C
  • Gajee, K
  • Sanderson, F
  • Smith, H
  • Hollinshead, K
  • Favager, C
  • Westwell, F
  • Pegg, C
  • Gabriel, C
  • Pagget, K
  • Sinclair, C
  • McLelland-Brooks, K
  • Ho, A
  • Black, K
  • Tempeton, K
  • Coles, H
  • Chenoweth, H
  • Auckland, C
  • Kerrison, C
  • Price, C
  • James, K
  • Gray, K
  • Nimako, K
  • Court, K
  • Game, F
  • Holmes, C
  • Duff, C
  • Shipman, K
  • Parmar, C
  • Laven, C
  • Jeffery, K
  • Duncan, C
  • Baxendale, H
ORCID
Venue
The Lancet
Publisher
Elsevier BV
Published
2021-05
Volume
397
Issue
10286
Pages
1725-1735
ISSN
  • 0099-5355 (ISSN-L)
  • 0140-6736
DOI
10.1016/s0140-6736(21)00790-x
PMC
PMC8064668
OpenAlex
W3159191704
Cited by
767
References
27
Citations by year
2026: 18 · 2025: 34 · 2024: 55 · 2023: 109 · 2022: 270 · 2021: 278
FWCI
56.38
Type
journal article
Language
en
Open access
Licence
Locations
  • The Lancet (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • ResearchOnline (Glasgow Caledonian University) (submittedVersion, cc-by-nc-nd)
  • UCL Discovery (University College London) (submittedVersion)
Funders
  • United Kingdom Department of Health and Social Care
  • Public Health England
  • National Institute for Health Research
Topics
  • Health Sciences › Medicine › Infectious Diseases › SARS-CoV-2 and COVID-19 Research
  • Social Sciences › Health › Vaccine Coverage and Hesitancy
  • Physical Sciences › Mathematics › Modeling and Simulation › COVID-19 epidemiological studies
Keywords
COVID-19 vaccination, BNT162b2 mRNA vaccine, ChAdOx1 nCoV-19 vaccine, vaccination coverage, healthcare workers, hospital staff, vaccine effectiveness, COVID-19 pandemic, asymptomatic testing, time to infection, shared frailty model, England, SIREN study, nosocomial infections
MeSH terms
COVID-19 Vaccines, BNT162 Vaccine, England, Health Personnel, Humans, Occupational Diseases, Prospective Studies, RNA, Messenger, Cohort Studies, Occupational Exposure, Treatment Outcome

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-10-06, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-10-06 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review