Antibody and T cell responses to a single dose of the AZD1222/Covishield vaccine in previously SARS-CoV-2 infected and naïve health care workers in Sri Lanka

  1. Chandima Jeewandara
  2. Achala Kamaladasa
  3. Pradeep Darshana Pushpakumara
  4. Deshni Jayathilaka
  5. Inoka Sepali Abayrathna
  6. Saubhagya Danasekara
  7. Dinuka Guruge
  8. Thushali Ranasinghe
  9. Shashika Dayarathne
  10. Thilagaraj Pathmanathan
  11. Gayasha Somathilaka
  12. Deshan Madhusanka
  13. Shyrar Tanussiya
  14. Tibutius TPJ
  15. Heshan Kuruppu
  16. Ayesha Wijesinghe
  17. Nimasha Thashmi
  18. Dushantha Milroy
  19. Achini Nandasena
  20. Nilanka Sanjeewani
  21. Ruwan Wijayamuni
  22. Sudath Samaraweera
  23. Lisa Schimanski
  24. T.K. Tan
  25. Tao Dong
  26. Graham S. Ogg
  27. Alain Townsend
  28. Gathsaurie Neelika Malavige

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Abstract

Background

In order to determine the immunogenicity of a single dose of the AZD1222/Covishield vaccine in a real-world situation, we assessed the immunogenicity, in a large cohort of health care workers in Sri Lanka.

Methods

SARS-CoV-2 antibodies was carried out in 607 naïve and 26 previously infected health care workers (HCWs) 28 to 32 days following a single dose of the vaccine. Haemagglutination test (HAT) for antibodies to the receptor binding domain (RBD) of the wild type virus, B.1.1.7, B.1.351 and the surrogate neutralization assay (sVNT) was carried out in 69 naïve and 26 previously infected individuals. Spike protein (pools S1 and S2) specific T cell responses were measured by ex vivo ELISpot IFNγ assays in 76 individuals.

Results

92.9% of previously naive HCWs seroconverted to a single dose of the vaccine, irrespective of age and gender; and ACE2 blocking antibodies were detected in 67/69 (97.1%) previously naïve vaccine recipients. Although high levels of antibodies were found to the RBD of the wild type virus, the titres for B.1.1.7 and B.1.351 were lower in previously naïve HCWs. Ex vivo T cell responses were observed to S1 in 63.9% HCWs and S2 in 31.9%. The ACE2 blocking titres measured by the sVNT significantly increased (p<0.0001) from a median of 54.1 to 97.9 % of inhibition, in previously infected HCWs and antibodies to the RBD for the variants B.1.1.7 and B.1.351 also significantly increased.

Discussion

a single dose of the AZD1222/Covishield vaccine was shown to be highly immunogenic in previously naïve individuals inducing antibody levels greater than following natural infection. In infected individuals, a single dose induced very high levels of ACE2 blocking antibodies and antibodies to RBDs of SARS-CoV-2 variants of concern.

Funding

We are grateful to the World Health Organization, UK Medical Research Council and the Foreign and Commonwealth Office.

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  1. ScreenIT

    SciScore for 10.1101/2021.04.09.21255194: (What is this?)

    Please note, not all rigor criteria are appropriate for all manuscripts.

    Table 1: Rigor

    Institutional Review Board StatementConsent: 633 HCWs, who received their first dose of the AZD1222/Covisheild vaccine between the 29th January to 5th of February 2021, were included in the study following informed written consent.
    IRB: Ethics approval was obtained from the Ethics Review Committee of University of Sri Jayewardenepura.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Sex as a biological variablenot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Detection of total antibodies to SARS-CoV-2: SARS-COV-2 specific total antibody (IgM, IgG and IgA) responses were assessed using WANTAI SARS-CoV-2 Ab ELISA (Beijing Wantai Biological Pharmacy Enterprise, China).
    SARS-CoV-2: SARS-COV-2 specific total antibody (IgM, IgG
    suggested: None
    SARS-COV-2
    suggested: None
    IgA
    suggested: None
    Inhibition percentage ≥ 25% in a sample was considered as positive for ACE2 blocking antibodies.
    ACE2 blocking antibodies.
    suggested: None
    Software and Algorithms
    SentencesResources
    Statistical analysis: GraphPad Prism version 6 was used for statistical analysis.
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)

    Results from OddPub: We did not detect open data. We also did not detect open code. Researchers are encouraged to share open data when possible (see Nature blog).

    Results from LimitationRecognizer: An explicit section about the limitations of the techniques employed in this study was not found. We encourage authors to address study limitations.

    Results from TrialIdentifier: No clinical trial numbers were referenced.

    Results from Barzooka: We did not find any issues relating to the usage of bar graphs.

    Results from JetFighter: We did not find any issues relating to colormaps.

    Results from rtransparent:
    • Thank you for including a conflict of interest statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a funding statement. Authors are encouraged to include this statement when submitting to a journal.
    • Thank you for including a protocol registration statement.

    About SciScore

    SciScore is an automated tool that is designed to assist expert reviewers by finding and presenting formulaic information scattered throughout a paper in a standard, easy to digest format. SciScore checks for the presence and correctness of RRIDs (research resource identifiers), and for rigor criteria such as sex and investigator blinding. For details on the theoretical underpinning of rigor criteria and the tools shown here, including references cited, please follow this link.

  2. Version published to 10.1101/2021.04.09.21255194v1 on medRxiv