Short-Term Immune Response After Inactivated SARS-CoV-2 (CoronaVac®, Sinovac) And ChAdOx1 nCoV-19 (Vaxzevria®, Oxford-AstraZeneca) Vaccinations in Thai Health Care Workers

  1. Watsamon Jantarabenjakul
  2. Napaporn Chantasrisawad
  3. Thanyawee Puthanakit
  4. Supaporn Wacharapluesadee
  5. Nattiya Hirankarn
  6. Vichaya Ruenjaiman
  7. Leilani Paitoonpong
  8. Gompol Suwanpimolkul
  9. Pattama Torvorapanit
  10. Rakchanok Pradit
  11. Jiratchaya Sophonphan
  12. Opass Putcharoen

Reviewed by

Read the full article See related articles

Listed in

Log in to save this article

Abstract

Background

Inactivated SARS-CoV-2 (CoronaVac®,Sinovac, or SV) and ChAdOx1 nCoV-19 (Vaxzevria®,Oxford-Astra Zeneca, or AZ) vaccines have been administered to the health care workers (HCWs) in Thailand.

Objective

To determine the short-term immune response after the SV and AZ vaccinations in HCWs.

Methods

In this prospective cohort study, HCWs who completed a 2-dose regimen of the SV or AZ were included. Immune response was evaluated by surrogate viral neutralization test (sVNT) and anti-SARS-CoV-2 total antibody. Blood samples were analyzed at 4 and 12 weeks after the complete SV vaccination and at 4 weeks after each dose of the AZ vaccination. The primary outcome was the seroconversion rate at 4-weeks after complete immunization.

Results

Overall, 185 HCWs with a median (IQR) age of 40.5(30.3-55.8) years (94 HCWs in the SV group and 91 in the AZ group) were included. At 4 weeks after completing the SV vaccination, 60.6% (95%CI:50.0-70.6%) had seroconversion evaluated by sVNT(≥68%inhibition), comparable to the patients recovered from mild COVID-19 infection(69.0%), with a rapid reduction to 12.2%(95%CI:6.3-20.8) at 12 weeks. In contrast, 85.7%(95%CI:76.8-92.2%) HCWs who completed the second dose of the AZ for 4 weeks had seroconversion, comparable to the COVID-19 pneumonia patients(92.5%). When using the anti-SAR-CoV-2 total antibody level(≥132 U/ml) criteria, only 71.3% HCWs in the SV group had seroconversion, compared to 100% in the AZ group.

Conclusion

A rapid decline of short-term immune response in the HCWs after the SV vaccination indicates the need for a vaccine booster, particularly during the ongoing spreading of the SAR-CoV-2 variants of concern.

Article activity feed

  1. ScreenIT

    SciScore for 10.1101/2021.08.27.21262721: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: The study was approved by the Research Ethics Review Committee, Faculty of Medicine, Chulalongkorn University, and was registered to the Thai Clinical Trial (TCTR20210325003).
    Consent: All participants were voluntary to receiving the SARS-CoV-2 vaccination and participating in the study with written informed consent.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    The Detection of Antibody Titers Against SARS-CoV-2: The antibody titers against SARS-CoV-2 were determined by the surrogate neutralizing antibody and total antibodies using the ELISA technique. 1.
    SARS-CoV-2
    suggested: None
    The protein-protein interaction between Horseradish peroxidase (HRP) conjugated recombinant SARS-CoV-2 RBD fragment (HRP-RBD), and the human ACE2 receptor protein (hACE2) can be blocked by neutralizing antibodies against SARS-CoV-2 RBD.
    human ACE2 receptor protein (hACE2
    suggested: None
    Moreover, the baseline serum of each participant in the vaccination groups was confirmed to be negative for the SARS-CoV-2 total antibodies.
    SARS-CoV-2 total antibodies.
    suggested: None
    10 The seroconversion rate was defined as the anti-SARS-CoV-2 total antibodies ≥132 U/ml as suggested by the US-FDA of the high titer for COVID-19 convalescent plasma.
    anti-SARS-CoV-2 total antibodies ≥132
    suggested: None
    9 The level of anti-SARS-CoV-2 total antibodies (measured in U/ml) from the Elecsys® test was converted to the BAU/ml following the first WHO International Standard for anti-SARS-CoV-2 immunoglobulin, which 1 U/ml is equivalent to 0.972 BAU/ml.11 Statistical Analysis: Demographics and clinical and laboratory parameters were described in descriptive statistics.
    anti-SARS-CoV-2 total antibodies
    suggested: None
    anti-SARS-CoV-2 immunoglobulin
    suggested: None
    The correlation between sVNT and anti-SARS-CoV-2 total antibodies was determined by the Spearman rank test.
    anti-SARS-CoV-2 total
    suggested: None
    Software and Algorithms
    SentencesResources
    STATA version 15.1 (Stata Corp., College Station, Texas) was used for statistical analysis.
    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:
    This study has some limitations. Firstly, there were no definitive cut-off level of the sVNT and the SARS-CoV-2 total antibodies for protection against both wild-type SARS-CoV-2 virus and the SARS-CoV-2 VOC. Therefore, a high sVNT ≥68% and 80%inhibition by the US-FDA were adopted to implicate the protective immunity. Moreover, previous studies reported the high correlation between the sVNT and the PRNT50 and the equivalent sVNTs of the convalescent sera of the severe COVID-19 patients. Secondly, both sVNT and the SARS-CoV-2 total antibodies only represented the humoral immune response. Further studies on the cellular immune responses after the vaccination are ongoing, comparing the T-cell activities by the ELISpot assay between the individuals who received the AZ and the SV vaccinations. Theoretically, the AZ vaccine, a viral vector vaccine platform, should have a better cell-mediated immune response than the SV vaccine, an inactivated virus vaccine platform. In general, a highly effective vaccine with the lowest possible side effects should be offered to the front-line HCWs. From our data, the HCWs who completed 2 doses of the SV vaccination should be considered for a booster vaccine, and the HCWs who received the first dose of the AZ vaccination should shorten the interval for the second dose.

    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.

  2. Version published to 10.1101/2021.08.27.21262721v1 on medRxiv