Serosurveillance among healthcare workers vaccinated with ChAdOx1 nCoV-19 Corona vaccine in a tertiary hospital of Kerala, India: prospective cohort studу

  1. S. K. Njarekkattuvalappil
  2. R. Bhaskaran
  3. V. Sree Raj
  4. P. Jose
  5. Aboobacker M. Rafi
  6. J. Thomas
  7. S. J. Innah
  8. L. Raphael
  9. U. G. Unnikrishnan
  10. P. Rajmohan
  11. Ch. Valsan
  12. P. Kuttichira

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Abstract

Aim . To evaluate antibody responses following two doses of ChAdOx1 nCoV-19 Corona vaccination in a tertiary care setting and the association of host factors like age, body mass index and comorbidities in determining this antibody response.

Materials and methods . This prospective serosurveillance study was done among healthcare workers of Jubilee Mission Medical College, vaccinated during January- April 2021. Blood samples were drawn from 170 participants after their first dose and from 156 participants after their second dose of Covishield TM to measure the specific Ig G antibodies against the recombinant S1 subunit of the S protein of SARS-CoV-2.

Results . The median level of anti-SARS-CoV-2 Ig G antibody 28–56 days after the first dose vaccination was 3.64 S/C (1.33, 7.24) and 11.6 S/C (8.61, 14.27) after 14 days of second dose vaccination. Protective levels of anti-SARS CoV-2 Ig G antibodies (≥ 9.5 S/C) was developed by 25 participants (14.7%, 95% confidence interval: 9.8% to 20.9%) after 28–56 days of first dose of vaccination and by 109 participants (69.9%, 95% confidence interval: 62% to 77%) after 14 days of second dose. Health care workers in the age group below 60 years (p = 0.027) and without comorbidities (p = 0.079) showed higher protective Ig G levels. But on multiple logistic regression only age under 60 years was found to be statistically significant.

Conclusion . After the first dose of the ChAdOx1 nCoV-19 vaccine, the formation of Ig G antibodies was observed, the level of which increased after the second dose. Among the various associated factors studied only the age of the participants below 60 years was found to be statistically significant for protective antibody levels. Follow up studies involving larger and different ethnic population is key to decoding the antibody response especially in the elderly and high-risk groups.

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  1. Version published to 10.47093/2218-7332.2022.376.07
  2. ScreenIT

    SciScore for 10.1101/2021.06.29.21259686: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: The current study is a prospective sero surveillance study initiated after obtaining the Institutional Ethics Committee approval from January 2021 to April 2021.
    Consent: After obtaining informed consent, a self-administered questionnaire in Google forms was filled by the participant (Annexure 1).
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line AuthenticationAuthentication: The protective levels post vaccination has not yet been validated.

    Table 2: Resources

    Antibodies
    SentencesResources
    Participants of the study were healthcare workers of JMMC & RI: (a) who have provided their pre-vaccination serum sample for SARS CoV-2 antibody estimation and found negative (b) who have taken the first dose of ChAdOx1 nCoV-19 Coronavirus vaccine (c) with no history or test result suggestive of Covid infection.
    RI
    suggested: None
    The samples were subjected to SARS-CoV-2 Ig G and total antibody testing using the VITROS anti SARS CoV-2 Ig G/Total Chemiluminescence kit manufactured by Ortho Clinical Diagnostics, USA (OCD).
    anti SARS
    suggested: None
    The VITROS anti-SARS-CoV-2 total assay can detect total antibodies (IgA, Ig M, and Ig G) against SARS-CoV-2 S protein.
    anti-SARS-CoV-2 total assay can detect total antibodies (IgA
    suggested: None
    SARS-CoV-2 S protein.
    suggested: None
    Anti SARS Cov-2 Ig G antibody levels have been tested using various platforms especially for the extraction of high titre Covid-19 Convalescent Plasma.
    Anti SARS Cov-2 Ig G
    suggested: None
    Software and Algorithms
    SentencesResources
    Data collected was entered into Microsoft Excel spread sheets and analyzed using IBM Statistical Package for Social Sciences (SPSS) version 25.
    Microsoft Excel
    suggested: (Microsoft Excel, RRID:SCR_016137)
    SPSS
    suggested: (SPSS, RRID:SCR_002865)

    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: We detected the following sentences addressing limitations in the study:
    Our limitations include a small sample size and exclusion of individuals who developed Covid-19 infection before or in between vaccination. We have also not looked into cell-mediated immune responses which could augment responses against Covid-19 virus.

    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.
    • No protocol registration statement was detected.

    Results from scite Reference Check: We found no unreliable references.

    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.

  3. Version published to 10.1101/2021.06.29.21259686v1 on medRxiv