Effectiveness of Covishield vaccine in preventing Covid-19 – A test-negative case-control study

  1. Stuti Pramod
  2. Dhanajayan Govindan
  3. Premkumar Ramasubramani
  4. Sitanshu Sekhar Kar
  5. Rakesh Aggarwal
  6. Nandhini Manoharan
  7. Palanivel Chinnakali
  8. Mahalakshmy Thulasingam
  9. Sonali Sarkar
  10. Molly Mary Thabah

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Abstract

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  1. Version published to 10.1016/j.vaccine.2022.02.014
  2. ScreenIT

    SciScore for 10.1101/2021.07.19.21260693: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: The study was approved by our institution’s ethics committee and all subjects provided an oral informed consent.
    Consent: The study was approved by our institution’s ethics committee and all subjects provided an oral informed consent.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Vaccination with Covishield had started in our institution on 16th January 2021, though some of our HCWs could receive the other vaccine by travelling to other areas.
    Covishield
    suggested: None
    Data on vaccination status, type of vaccine, test positivity, presence of symptoms and comorbidities were collected using a telephonically administered questionnaire, captured using EpiCollect5 application and analysed using STATA V14.0.
    STATA
    suggested: (Stata, RRID:SCR_012763)

    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:
    The case-control design that we used, despite its several limitations, has the advantage of permitting assessment of association of intervention with disease even when only a few cases are available, and thus allowed us to detect this effect. Though our analysis did show a statistically significant protection against moderately severe disease after Covishield, the confidence intervals of the estimate are relatively broad and further data on this association may be needed to improve our confidence in this observation. Our study has two key limitations. First, the study design used relies heavily on reporting for RT-PCR testing. Thus, it may overestimate the benefit of vaccination if the vaccinated HCW, whether asymptomatic or having symptoms suggestive of Covid-19, were to believe that they were unlikely to have Covid-19 and decide not to report for testing. Second, since genomic sequencing of SARS-CoV-2 had not been done in our study participants, we were unable to assess the VE separately for the ancestral strain and variant strains of the virus. In conclusion, our data show that Covishield vaccination, either as one dose or in a 2-dose schedule, was effective in halving the frequency of Covid-19 disease among HCWs in a period when B.1.617.2 strain of SARS-CoV-2 was the dominant strain circulating in our area, and had an even greater effect on preventing a more severe and clinically relevant form of this disease.

    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 10.1101/2021.07.19.21260693v1 on medRxiv