Seroprevalence of anti-SARS-CoV-2 antibodies in Thai adults during the first three epidemic waves

  1. Hatairat Lerdsamran
  2. Anek Mungaomklang
  3. Sopon Iamsirithaworn
  4. Jarunee Prasertsopon
  5. Witthawat Wiriyarat
  6. Suthee Saritsiri
  7. Ratikorn Anusorntanawat
  8. Nirada Siriyakorn
  9. Poj Intalapaporn
  10. Somrak Sirikhetkon
  11. Kantima Sangsiriwut
  12. Worawat Dangsakul
  13. Suteema Sawadpongpan
  14. Nattakan Thinpan
  15. Kuntida Kitidee
  16. Pilailuk Okada
  17. Ranida Techasuwanna
  18. Noparat Mongkalangoon
  19. Kriengkrai Prasert
  20. Pilaipan Puthavathana

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Abstract

This study determined the presence of anti-SARS-CoV-2 antibodies in 4964 individuals, comprising 300 coronavirus disease-19 (COVID-19) prepandemic serum samples, 142 COVID-19 patients, 2113 individuals at risk due to their occupations, 1856 individuals at risk due to sharing workplaces or communities with COVID-19 patients, and 553 Thai citizens returning after spending extended periods of time in countries with a high disease prevalence. We recruited participants between May 2020 and May 2021, which spanned the first two epidemic waves and part of the third wave of the COVID-19 outbreaks in Thailand. Their sera were tested in a microneutralization and a chemiluminescence immunoassay for IgG against the N protein. Furthermore, we performed an immunofluorescence assay to resolve discordant results between the two assays. None of the prepandemic sera contained anti-SARS-CoV-2 antibodies, while antibodies developed in 88% (15 of 17) of the COVID-19 patients at 8–14 days and in 94–100% of the patients between 15 and 60 days after disease onset. Neutralizing antibodies persisted for at least 8 months, longer than IgG antibodies. Of the 2113 individuals at risk due to their occupation, none of the health providers, airport officers, or public transport drivers were seropositive, while antibodies were present in 0.44% of entertainment workers. Among the 1856 individuals at risk due to sharing workplaces or communities with COVID-19 patients, seropositivity was present in 1.9, 1.5, and 7.5% of the Bangkok residents during the three epidemic waves, respectively, and in 1.3% of the Chiang Mai people during the first epidemic wave. The antibody prevalence varied between 6.5 and 47.0% in 553 Thai people returning from high-risk countries. This serosurveillance study found a low infection rate of SARS-CoV-2 in Thailand before the emergence of the Delta variant in late May 2021. The findings support the Ministry of Public Health’s data, which are based on numbers of patients and contact tracing.

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  1. Version published to 10.1371/journal.pone.0263316
  2. ScreenIT

    SciScore for 10.1101/2022.01.18.22269501: (What is this?)

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

    Table 1: Rigor

    EthicsIRB: Ethical statement: Usage of human sera from participants of age older than 18 received approval from the Mahidol University Central Institutional Review Board (MU-CIRB) under protocol number MU-COVID2020.001/2503.
    Consent: In the enrollment process for participants in groups 2 and 3, epidemiologists explained the purpose of the study to obtain written consent for interviewing about their demographics, occupation, workplace, residence, and general health condition, including a donation of 5-8 ml of blood, with specimens labeled using ID codes. 4) Thai citizens in state quarantines, when arrived Thailand after extended duties in countries with known SARS-CoV-2 outbreaks.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line Authenticationnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Blood specimens were collected for anti-SARS-CoV-2 antibody testing [along with real-time reverse transcription-polymerase chain reaction (RT-PCR)] to support active case surveillance activities conducted by the Institute for Urban Disease Control and Prevention (IUDC), DDC, MoPH.
    anti-SARS-CoV-2
    suggested: None
    When results of the two assays were concordant, the test serum was considered positive or negative for anti-SARS antibodies.
    anti-SARS
    suggested: None
    A titer of 10 or greater was considered positive for NT antibody.
    NT
    suggested: None
    Experimental Models: Cell Lines
    SentencesResources
    The assay employed SARS-CoV-2-infected Vero cells deposited on microscopic slides as the test antigens.
    Vero
    suggested: CLS Cat# 605372/p622_VERO, RRID:CVCL_0059)
    Software and Algorithms
    SentencesResources
    Chemiluminescence immunoassay: CLIA using Architect auto-analyzer (Abbott Laboratories, USA) is the two-step, fully automated immunoassay that qualitatively detected binding between the SARS-CoV-2 nucleoprotein (N) antigen coated on paramagnetic microparticles and human IgG in the test sera.
    Abbott Laboratories
    suggested: None
    Statistical analysis: R square (R2), mean, and standard deviation (SD) were determined, and figures were drawn using GraphPad Prism version 8.4.3 for Windows (GraphPad Software, La Jolla, California, USA).
    GraphPad Prism
    suggested: (GraphPad Prism, RRID:SCR_002798)
    GraphPad
    suggested: (GraphPad Prism, RRID:SCR_002798)
    The McNemar test was carried out and 95% confidence interval (95% CI) calculated by SPSS Statistic software version 18.0.
    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: 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.
    • 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 10.1101/2022.01.18.22269501v1 on medRxiv