Humoral Antibody Kinetics with ChAdOx1-nCOV (Covishield TM ) and BBV-152 (Covaxin TM ) Vaccine among Indian Healthcare workers: A 6-month Longitudinal Cross-sectional Coronavirus Vaccine-induced Antibody Titre (COVAT) Study

  1. Awadhesh Kumar Singh
  2. Sanjeev Ratnakar Phatak
  3. Ritu Singh
  4. Kingshuk Bhattacharjee
  5. Nagendra Kumar Singh
  6. Arvind Gupta
  7. Arvind Sharma

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Abstract

Background and Aims

There is limited data available on longitudinal humoral antibody dynamics following two doses of ChAdOx1-nCOV (Covishield TM ) and BBV-152 (Covaxin TM ) vaccine against SARS-CoV-2 among Indians.

Methods

We conducted a 6-month longitudinal study in vaccinated healthcare workers by serially measuring quantitative anti-spike antibody at 3-weeks, 3-months and 6- months after the completion of second dose. Geometric mean titer (GMT) and linear mixed models were used to assess the dynamics of antibody levels at 6 months.

Results

Of the 481 participants, GMT of anti-spike antibody decreased by 56% at 6- months regardless of demographics and comorbidities in 360 SARS-CoV-2 naive individuals, significantly in hypertensives. Participants with past infection had significantly higher GMT at all time points compared to naive individuals. Among SARS-CoV-2 naive cohorts, a significantly higher GMT was noted amongst the Covishield recipients at all time points, but there was a 44% decline in GMT at 6- month compared to peak titer period. Decline in GMT was insignificant (8%) in Covaxin recipients at 6-month despite a lower GMT at all time points vs. Covishield. There was 5.6-fold decrease in seropositivity rate at 6-month with both vaccines. Participants with type 2 diabetes mellitus have a lower seropositivity rate at all the time points. While seropositivity rate was significantly higher with Covishield vs. Covaxin at all time points except at 6-month where Covaxin recipients had a higher seropositivity, although no difference in seropositivity was noted in propensity-matched analysis.

Conclusions

There is waning humoral antibody response following two doses of either vaccine at six months.

Highlights:

  • We assessed humoral antibody dynamics following two doses of the two vaccines used in India until 6 months.

  • Our study of 481 health care workers showed a significant decrease in the anti-spike antibody at 6-months.

  • Reduction in antibody was regardless of demographics, comorbidities and the vaccine type.

  • T2DM cohorts had lowest seropositivity, while hypertensive had significant antibody decline at 6-month.

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  1. ScreenIT

    SciScore for 10.1101/2022.02.03.22270182: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: COVAT study was a pan-India, cross-sectional study approved by the ethical committee of Thakershy Charitable Trust, Ahmedabad, Gujarat, India.
    Consent: Informed consent was taken on Google-sheet from all the participants who volunteered to participate in this study.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Summarily, all adult health care workers (HCWs) of >18 years of age who completed two dose of either vaccine and had completed a total of four measured anti-spike antibody titre until 6-month of second dose were included in this analysis.
    anti-spike
    suggested: None
    The IgG antibodies to SARS-CoV-2 directed against the spike protein (S-antigen, both S1 and S2 protein) were assayed with LIASON® S1/S2 quantitative antibody detection kit (DiaSorin Saluggia, Italy) using indirect chemiluminescence immunoassay (CLIA).
    IgG
    suggested: None
    Software and Algorithms
    SentencesResources
    Entire statistical analysis was carried out with Statistical Package for Social Sciences (SPSS Complex Samples
    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:
    However, we do acknowledge several limitations. First, we have used a convenience sampling in the present study which amounts to selection bias. Second, our study had all health care workers, mostly healthy persons and therefore they may not represent the general population. Third, we did not have dilution and neat values for those sample that hit both the upper and lower limit of kit value that assessed anti-spike antibody. This could have likely underestimated the GMT in those recipients who had undiluted plateaued value. Fourth, using the mixed model linear analysis may lead to loss in power to detect the significant difference due to double fitting of the study parameter. Fifth, we used a binary logistic regression to identify the independent predictors of breakthrough infection but this model may miss out any predictor variable which may have non-linear relationship with the outcome variable. Lastly, we have measured only anti-spike binding antibody and could not assess NAb and cell-mediated immune response such as Th-1 and Th-2 dependent antibody or cytokines (primarily due to the lack of standardized commercial labs in India). Although a high correlation with spike protein-based ELISA and different antibody classes to NAb have been documented recently [27]. Finally, because of logistic issues (due to lockdown) during pandemic we could not measure the baseline anti-spike antibody titre prior to the first dose of vaccine.

    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

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  2. Version published to 10.1101/2022.02.03.22270182v1 on medRxiv
  3. Version published to 10.1016/j.dsx.2022.102424