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Cited by 2,889SARS-CoV-2 and COVID-19 ResearchVaccine Coverage and HesitancyCOVID-19 epidemiological studies

Effectiveness of Covid-19 Vaccines against the B.1.617.2 (Delta) Variant

Open access
Lopez Bernal, Jamie, Andrews, Nick, Gower, Charlotte, Gallagher, Eileen, Simmons, Ruth, Thelwall, Simon, Stowe, Julia, Tessier, Elise +11 more·2021·New England Journal of Medicine
DOI 10.1056/nejmoa2108891PMC PMC8314739

Published version of a preprint

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Abstract

Abstract Background The B.1.617.2 COVID-19 variant has contributed to the surge in cases in India and has now been detected across the globe, including a notable increase in cases in the UK. We estimate the effectiveness of the BNT162b2 and ChAdOx1 COVID-19 vaccines against this variant. Methods A test negative case control design was used to estimate the effectiveness of vaccination against symptomatic disease with both variants over the period that B.1.617.2 began circulating with cases identified based on sequencing and S-gene target status. Data on all symptomatic sequenced cases of COVID-19 in England was used to estimate the proportion of cases with B.1.617.2 compared to the predominant strain (B.1.1.7) by vaccination status. Results Effectiveness was notably lower after 1 dose of vaccine with B.1.617.2 cases 33.5% (95%CI: 20.6 to 44.3) compared to B.1.1.7 cases 51.1% (95%CI: 47.3 to 54.7) with similar results for both vaccines. With BNT162b2 2 dose effectiveness reduced from 93.4% (95%CI: 90.4 to 95.5) with B.1.1.7 to 87.9% (95%CI: 78.2 to 93.2) with B.1.617.2. With ChAdOx1 2 dose effectiveness reduced from 66.1% (95% CI: 54.0 to 75.0) with B.1.1.7 to 59.8% (95%CI: 28.9 to 77.3) with B.1.617.2. Sequenced cases detected after 1 or 2 doses of vaccination had a higher odds of infection with B.1.617.2 compared to unvaccinated cases (OR 1.40; 95%CI: 1.13-1.75). Conclusions After 2 doses of either vaccine there were only modest differences in vaccine effectiveness with the B.1.617.2 variant. Absolute differences in vaccine effectiveness were more marked with dose 1. This would support maximising vaccine uptake with two doses among vulnerable groups.

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Claims the paper makes

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  • Findingown data

    First-dose vaccine effectiveness estimates were similar for BNT162b2 and ChAdOx1 nCoV-19.

    “the results were similar for both vaccines.”
    • Also stated in: § Vaccine Effectiveness Estimates · plain
      “Results for the first dose were similar for both vaccines, with an absolute difference in vaccine effectiveness against the delta variant as compared with the alpha variant of 11.9 percentage points with the BNT162b2 vaccine and 18.7 percentage points with the ChAdOx1 nCoV-19 vaccine.”
    Quote in the paperNot a substantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.
  • Findingown data

    After a single dose of either BNT162b2 or ChAdOx1 nCoV-19, vaccine effectiveness against symptomatic Covid-19 was lower in people infected with the delta variant (30.7%; 95% CI, 25.2 to 35.7) than in those infected with the alpha variant (48.7%; 95% CI, 45.5 to 51.7).

    “Effectiveness after one dose of vaccine (BNT162b2 or ChAdOx1 nCoV-19) was notably lower among persons with the delta variant (30.7%; 95% confidence interval [CI], 25.2 to 35.7) than among those with the alpha variant (48.7%; 95% CI, 45.5 to 51.7); the results were similar for both vaccines.”
    • Also stated in: § Vaccine Effectiveness Estimates · plain
      “In the “any vaccine” analysis, in which data from the persons who received either vaccine were pooled, effectiveness was notably lower after the first vaccine dose among persons with the delta variant (30.7%; 95% confidence interval [CI], 25.2 to 35.7) than among those with the alpha variant (48.7%; 95% CI, 45.5 to 51.7).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.
  • Findingown data

    With ChAdOx1 nCoV-19, two-dose vaccine effectiveness against symptomatic disease was 74.5% (95% CI, 68.4 to 79.4) for the alpha variant and 67.0% (95% CI, 61.3 to 71.8) for the delta variant.

    “With the ChAdOx1 nCoV-19 vaccine, the effectiveness of two doses was 74.5% (95% CI, 68.4 to 79.4) among persons with the alpha variant and 67.0% (95% CI, 61.3 to 71.8) among those with the delta variant.”
    • Also stated in: § Vaccine Effectiveness Estimates · plain
      “The effectiveness with two doses of the ChAdOx1 nCoV-19 vaccine was lower than with the BNT162b2 vaccine; however, with the ChAdOx1 nCoV-19 vaccine, the difference in effectiveness between the alpha and delta variants was small (74.5% [95% CI, 68.4 to 79.4] and 67.0% [95% CI, 61.3 to 71.8], respectively).”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.
  • Findingown data

    Two-dose vaccine effectiveness against either variant was lower with ChAdOx1 nCoV-19 than with BNT162b2.

    “The effectiveness with two doses of the ChAdOx1 nCoV-19 vaccine was lower than with the BNT162b2 vaccine; however, with the ChAdOx1 nCoV-19 vaccine, the difference in effectiveness between the alpha and delta variants was small (74.5% [95% CI, 68.4 to 79.4] and 67.0% [95% CI, 61.3 to 71.8], respectively).”
    • Also stated in: § Discussion · plain
      “Vaccine effectiveness against either variant was smaller after the receipt of two doses of the ChAdOx1 nCoV-19 vaccine than after the receipt of two doses of the BNT162b2 vaccine, a finding that is consistent with reported clinical trial findings.7,8”
    Quote in the paperSubstantial claim0 of 2 sources checked
    • cites [7] Polack FP, Thomas SJ, Kitchin N, et al. Safety and efficacy of the BNT162b2 mRNA Covid-19 vaccine. N Engl J Med 2020; 383: 2603- 2615. 33301246 PMC7745181 source

      Not checked in the free run.

    • cites [8] Voysey M, Clemens SAC, Madhi SA, et al. Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet 2021; 397: 99- 111. 33306989 PMC7723445 source

      Not checked in the free run.

    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.
  • Findingown data

    Among sequenced samples linked to the SARS-CoV-2 testing data set, 92.9% were linked to vaccination status data.

    “Among all the sequenced samples that were linked to the SARS-CoV-2 testing data set, 92.9% were linked to data on vaccination status.”
    Quote in the paperSubstantial claim
  • May combine two claims. 17
  • The quote only partly states this claim. 2
  • Classified as probably not a substantial claim. 8

  • May combine two claims.

    Findingown data

    With BNT162b2, two-dose vaccine effectiveness against symptomatic disease was 93.7% (95% CI, 91.6 to 95.3) for the alpha variant and 88.0% (95% CI, 85.3 to 90.1) for the delta variant.

    “With the BNT162b2 vaccine, the effectiveness of two doses was 93.7% (95% CI, 91.6 to 95.3) among persons with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) among those with the delta variant.”
    • Also stated in: § Vaccine Effectiveness Estimates · plain
      “With the BNT162b2 vaccine, a small difference in effectiveness between variants was seen after the second dose: 93.7% (95% CI, 91.6 to 95.3) with the alpha variant and 88.0% (95% CI, 85.3 to 90.1) with the delta variant.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.

  • May combine two claims.

    Findingown data

    The absolute difference in first-dose vaccine effectiveness between the delta and alpha variants was 11.9 percentage points for BNT162b2 and 18.7 percentage points for ChAdOx1 nCoV-19, or approximately 12 to 19 percentage points overall.

    “Results for the first dose were similar for both vaccines, with an absolute difference in vaccine effectiveness against the delta variant as compared with the alpha variant of 11.9 percentage points with the BNT162b2 vaccine and 18.7 percentage points with the ChAdOx1 nCoV-19 vaccine.”
    • Also stated in: § Discussion · plain
      “We found that the absolute difference in vaccine effectiveness against symptomatic disease with one dose of vaccine with the delta variant as compared with the alpha variant was approximately 12 to 19 percentage points.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.

  • May combine two claims.

    Findingown data

    Overall, the study found high levels of vaccine effectiveness against symptomatic disease with the delta variant after two doses, with a clear effect for both vaccines.

    “Overall, we found high levels of vaccine effectiveness against symptomatic disease with the delta variant after the receipt of two doses.”
    • Also stated in: § Discussion · boosted
      “A clear effect was noted with both vaccines, with high levels of effectiveness after two doses.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    In the pooled any-vaccine analysis, two-dose vaccine effectiveness was 87.5% (95% CI, 85.1 to 89.5) against the alpha variant and 79.6% (95% CI, 76.7 to 82.1) against the delta variant.

    “In the “any vaccine” analysis, the vaccine effectiveness was 87.5% (95% CI, 85.1 to 89.5) with the alpha variant and 79.6% (95% CI, 76.7 to 82.1) with the delta variant.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.

  • May combine two claims. The quote only partly states this claim.

    Findingown data

    The study included 19,109 sequenced cases; the alpha variant was detected in 14,837 samples and the delta variant in 4,272 samples.

    “In an analysis that was restricted to including only persons at least 16 years of age who had symptomatic Covid-19 caused by the alpha or delta variant and who had been vaccinated with either ChAdOx1 nCoV-19 or BNT162b2 according to an appropriate schedule, 19,109 sequenced cases were included (Fig. S1 in the Supplementary Appendix). The alpha variant was detected in 14,837 samples, and the delta”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Findingown data

    Among sequenced samples originally tested with the TaqPath assay, 95.3% of S target-positive cases were the delta variant and 99.6% of S target-negative cases were the alpha variant.

    “Among sequenced samples that were originally tested with the use of the TaqPath assay, a high correlation was seen between S target status and the two variants under investigation, with 95.3% of the S target–positive cases identified as having the delta variant and 99.6% of the S target–negative cases identified as having the alpha variant (Tables S1 and S2).”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    Stratifying the post-first-dose period into 21-55 days and 56 or more days showed a possible indication of waning efficacy against the alpha variant with BNT162b2 and against the delta variant with ChAdOx1 nCoV-19.

    “Table S3, in which the period after the first dose is stratified according to the period of 21 to 55 days and the period of 56 or more days, shows a possible indication of waning efficacy against the alpha variant with the BNT162b2 vaccine and against the delta variant with the ChAdOx1 nCoV-19 vaccine.”
    Quote in the paperNot a substantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Findingown data

    Few cases of either variant occurred in people older than 70 years, and only nine cases, all alpha, occurred among care home residents.

    “Few cases of either variant were seen in persons older than 70 years of age, and only nine cases (all of which were with the alpha variant) occurred among care home residents.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    The difference in vaccine effectiveness between the delta and alpha variants was much smaller after two doses than after one dose, and the differences after two doses were small.

    “Only modest differences in vaccine effectiveness were noted with the delta variant as compared with the alpha variant after the receipt of two vaccine doses.”
    • Also stated in: § Vaccine Effectiveness Estimates · plain
      “The difference in vaccine effectiveness was much smaller among persons who had received the second dose of vaccine.”
    • Also stated in: § Discussion · plain
      “However, the differences in vaccine effectiveness after two doses were small.”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.

  • May combine two claims.

    Findingown data

    Cases with the delta variant differed from alpha cases in having higher proportions with foreign travel history, cases in recent calendar weeks, residence in certain regions, and Asian ethnic backgrounds, while age and deprivation distributions were similar.

    “Key differences with the delta variant included a higher proportion of persons with a history of foreign travel; a higher proportion of persons with cases in the most recent weeks (calendar weeks 18 to 20); a higher proportion of persons with cases in the northwest region, London, and the east of England; and a higher proportion of persons in the “Indian or British Indian,” “Pakistani or British”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Findingown data

    In the test-negative case-control analysis, estimated vaccine effectiveness against symptomatic disease with the delta variant was approximately 36% with a single dose of BNT162b2 and approximately 30% with a single dose of ChAdOx1 nCoV-19.

    “In the test-negative case–control analysis, the estimated vaccine effectiveness against symptomatic disease with the delta variant was approximately 36% with a single dose of the BNT162b2 vaccine and approximately 30% with a single dose of the ChAdOx1 nCoV-19 vaccine; the effectiveness was approximately 88% with two doses of the BNT162b2 vaccine and approximately 67% with two doses of the ChAdOx1”
    Quote in the paperSubstantial claim
    • The authors state this as an assumption: The accuracy of sequencing would not depend on the variant.
    • The authors state this as an assumption: The propensity among symptomatic persons to get tested would not differ according to variant.

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Premisecitation

    P681R is at the S1-S2 cleavage site, and strains with mutations at that site may have increased replication, leading to higher viral loads and increased transmission.

    “P681R is at the S1–S2 cleavage site, and it appears that strains with mutations at that site may have increased replication, which leads to higher viral loads and increased transmission.24”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [24] Johnson BA, Xie X, Kalveram B, et al. Furin cleavage site is key to SARS-CoV-2 pathogenesis. August 26, 2020 (https://www.biorxiv.org/content/10.1101/2020.08.26.268854v1). preprint.

      Not checked in the free run.

  • May combine two claims.

    Study design and conductreasoning

    Using a test-negative case-control design helped control for differences in health-seeking behavior between vaccinated and unvaccinated persons and for biases related to health-seeking behavior, access to testing, and case ascertainment.

    “The use of a test-negative case–control design helped us to control for differences in health-seeking behavior between vaccinated persons and unvaccinated persons.”
    • Also stated in: § Study Design · plain
      “This approach helps to control for biases related to health-seeking behavior, access to testing, and case ascertainment.”
    Quote in the paperSubstantial claim

  • May combine two claims.

    Premisecitation

    Among sequenced samples that tested positive for the S target, the delta variant accounted for 72.2% in April 2021 and 93.0% in May 2021 (as of May 12, 2021).

    “Among sequenced samples that tested positive for the S target, the delta variant was in 72.2% of the samples in April 2021 and in 93.0% in May (as of May 12, 2021).4”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4] Public Health England. SARS-CoV-2 variants of concern and variants under investigation in England. Technical briefing 11. May 13, 2021 (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/986380/Variants_of_Concern_VOC_Technical_Briefing_11_England.pdf).

      Not checked in the free run.

  • Classified as probably not a substantial claim.

    Study design and conductcitation

    Assignment of cases to the delta variant on the basis of S target status was restricted to the week commencing April 12, 2021, and onward to aim for high specificity of S target-positive testing for the delta variant.

    “Assignment to the delta variant on the basis of S target status was restricted to the week commencing April 12, 2021, and onward in order to aim for high specificity of S target–positive testing for the delta variant.4”
    Quote in the paperSubstantial claim0 of 1 sources checked
    • cites [4] Public Health England. SARS-CoV-2 variants of concern and variants under investigation in England. Technical briefing 11. May 13, 2021 (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/986380/Variants_of_Concern_VOC_Technical_Briefing_11_England.pdf).

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Premisecitation

    The proportion of all positive samples that were sequenced increased from approximately 10% in February 2021 to approximately 60% in May 2021.

    “The proportion of all positive samples that were sequenced increased from approximately 10% in February 2021 to approximately 60% in May 2021.4”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [4] Public Health England. SARS-CoV-2 variants of concern and variants under investigation in England. Technical briefing 11. May 13, 2021 (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/986380/Variants_of_Concern_VOC_Technical_Briefing_11_England.pdf).

      Not checked in the free run.

  • May combine two claims.

    Study design and conductown data

    Findings were similar to those in cases occurring during the first 2 weeks after the first vaccine dose, which helps rule out unmeasured confounders associated with vaccination likelihood and variant exposure.

    “Findings were also similar to those in cases that occurred during the first 2 weeks after receipt of the first vaccine dose (Table S4), which helps to rule out unmeasured confounders associated with both the likelihood of being vaccinated and the likelihood of being exposed to a variant.”
    Quote in the paperSubstantial claim

  • Classified as probably not a substantial claim.

    Study design and conductreasoning

    Vaccine effectiveness estimates were compared with unvaccinated persons and with persons with symptom onset 4 to 13 days after vaccination to help account for differences in underlying risk of infection.

    “Comparison was made with unvaccinated persons and with persons who had symptom onset in the period of 4 to 13 days after vaccination in order to help account for differences in underlying risk of infection.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

    Study design and conductreasoning

    Low sensitivity or specificity of PCR testing could affect one variant more than the other, although it might be expected to affect the alpha variant more than the delta variant.

    “Low sensitivity or specificity of PCR testing could also affect one variant more than another, although this might be expected to affect the alpha variant more than the delta variant, given that, with an emerging variant, more cases may be detected earlier in infection, which may result in higher viral loads and increased sensitivity and specificity.”
    Quote in the paperNot a substantial claim

  • May combine two claims.

    Study design and conductnone given

    Differences in vaccine coverage among population groups with different exposure to the delta variant may have affected the secondary analysis but should not have affected the test-negative case-control design.

    “Although we controlled for race or ethnic group, region, and an index of multiple deprivation, differences in vaccine coverage among population groups that may have more or less exposure to the delta variant may have affected the secondary analysis but should not have affected the test-negative case–control design.”
    Quote in the paperSubstantial claim

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductcitation

    There may be differences among the populations that received each vaccine, such as younger health care workers being more likely to receive BNT162b2 and persons in clinical risk groups more likely to receive ChAdOx1 nCoV-19.

    “There may also be differences among the populations that received each vaccine — for example, in younger age groups, health care workers are more likely to have received the BNT162b2 vaccine, whereas persons in clinical risk groups are more likely to have received the ChAdOx1 nCoV-19 vaccine.11”
    Quote in the paperNot a substantial claim0 of 1 sources checked
    • cites [11] Hall VJ, Foulkes S, Saei A, et al. COVID-19 vaccine coverage in health-care workers in England and effectiveness of BNT162b2 mRNA vaccine against infection (SIREN): a prospective, multicentre, cohort study. Lancet 2021; 397: 1725- 1735. 33901423 PMC8064668 source

      Not checked in the free run.

  • Probably not a substantial claim: may not pass S3 (load-bearing).

    Study design and conductreasoning

    The study findings are observational and should be interpreted with caution.

    “Our study has several limitations. The findings are observational and should be interpreted with caution.”
    Quote in the paperNot a substantial claim
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  • The authors state this as an assumption.

    For the secondary analysis, if a vaccine had some efficacy and was equally effective against both variants, a similar proportion of cases with either variant would be expected in unvaccinated and vaccinated persons; if the vaccine was less effective against delta than alpha, delta would make up a higher proportion of cases occurring more than 3 weeks after vaccination than among unvaccinated.

    “The underlying assumption was that if the vaccine had some efficacy and was equally effective against each variant, a similar proportion of cases with either variant would be expected in unvaccinated persons and in vaccinated persons. Conversely, if the vaccine was less effective against the delta variant than against the alpha variant, then the delta variant would be expected to make up a higher”

  • The authors state this as an assumption.

    The accuracy of sequencing would not depend on the variant.

    “that is, the accuracy of the sequencing would not depend on the variant”

  • The authors state this as an assumption.

    The propensity among symptomatic persons to get tested would not differ according to variant.

    “and the propensity among symptomatic persons to get tested would not differ according to variant.”

  • The paper relies on this without support.

    The effectiveness of BNT162b2 and ChAdOx1 nCoV-19 against the delta variant was unclear or limited before this study.

    “The effectiveness of the BNT162b2 and ChAdOx1 nCoV-19 vaccines against this variant has been unclear.”
    “Data on the effectiveness of Covid-19 vaccines against clinical outcomes with this variant have been limited.”
4 of 4

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Authors
Lopez Bernal, J., Andrews, N., Gower, C., Gallagher, E., Simmons, R., Thelwall, S., Stowe, J., Tessier, E., Groves, N., Dabrera, G., Myers, R., Campbell, C. N. J., Amirthalingam, G., Edmunds, M., Zambon, M., Brown, K. E., Hopkins, S., Chand, M., & Ramsay, M.
Affiliations
  • From Public Health England (J.L.B., N.A., C.G., E.G., R.S., S.T., J.S., E.T., N.G., G.D., R.M., C.N.J.C., G.A., M.E., M.Z., K.E.B., S.H., M.C., M.R.), the National Institute of Health Research (NIHR) Health Protection Research Unit in Vaccines and Immunisation, London School of Hygiene and Tropical Medicine (J.L.B., N.A., C.N.J.C., G.A., K.E.B., M.R.), the NIHR Health Protection Research Unit in Respiratory Infections, Imperial College London (J.L.B., M.Z.), and Guy’s and St. Thomas’ Hospital NHS Trust (M.C.), London, and Healthcare Associated Infections and Antimicrobial Resistance, University of Oxford, Oxford (S.H.) — all in the United Kingdom.
  • Public Health England (GB)
ORCID
Venue
New England Journal of Medicine
Publisher
Massachusetts Medical Society
Published
2021-08-12
Volume
385
Issue
7
Pages
585-594
ISSN
  • 0028-4793 (ISSN-L)
  • 1533-4406
DOI
10.1056/nejmoa2108891
PMC
PMC8314739
OpenAlex
W3184226105
Cited by
2,889
References
26
Citations by year
2026: 37 · 2025: 82 · 2024: 184 · 2023: 431 · 2022: 1320 · 2021: 832 · 2020: 1
FWCI
219.33
Type
journal article
Language
en
Open access
Licence
cc-by-nc-nd
Locations
  • New England Journal of Medicine (publishedVersion)
  • medRxiv (acceptedVersion, cc-by-nc-nd)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • Wellcome Trust
  • Public Health England
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 vaccines, B.1.1.7 Alpha variant, vaccine effectiveness, BNT162b2, ChAdOx1 nCoV-19 vaccine, two-dose vaccination, symptomatic COVID-19, test-negative case-control design
MeSH terms
Immunogenicity, Vaccine, COVID-19, SARS-CoV-2, COVID-19 Vaccines, Adolescent, Adult, Aged, Aged, 80 and over, Female, United Kingdom, Humans, Male, Middle Aged, Case-Control Studies, Treatment Outcome, Young Adult, Vaccine Potency

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