CalScope: Monitoring Severe Acute Respiratory Syndrome Coronavirus 2 Seroprevalence From Vaccination and Prior Infection in Adults and Children in California May 2021–July 2021

  1. Megha L Mehrotra
  2. Esther Lim
  3. Katherine Lamba
  4. Amanda Kamali
  5. Kristina W Lai
  6. Erika Meza
  7. Irvin Szeto
  8. Peter Robinson
  9. Cheng-ting Tsai
  10. David Gebhart
  11. Noemi Fonseca
  12. Andrew B Martin
  13. Catherine Ley
  14. Steve Scherf
  15. James Watt
  16. David Seftel
  17. Julie Parsonnet
  18. Seema Jain

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Abstract

Background

Understanding the distribution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies from vaccination and/or prior infection is critical to the public health response to the pandemic. CalScope is a population-based serosurvey in 7 counties in California.

Methods

We invited 200 000 randomly sampled households to enroll up to 1 adult and 1 child between April 20, 2021 and June 16, 2021. We tested all specimens for antibodies against SARS-CoV-2 nucleocapsid and spike proteins, and each participant completed an online survey. We classified participants into categories: seronegative, antibodies from infection only, antibodies from infection and vaccination, and antibodies from vaccination only.

Results

A total of 11 161 households enrolled (5.6%), with 7483 adults and 1375 children completing antibody testing. As of June 2021, 33% (95% confidence interval [CI], 28%–37%) of adults and 57% (95% CI, 48%–66%) of children were seronegative; 18% (95% CI, 14%–22%) of adults and 26% (95% CI, 19%–32%) of children had antibodies from infection alone; 9% (95% CI, 6%–11%) of adults and 5% (95% CI, 1%–8%) of children had antibodies from infection and vaccination; and 41% (95% CI, 37%–45%) of adults and 13% (95% CI, 7%–18%) of children had antibodies from vaccination alone.

Conclusions

As of June 2021, one third of adults and most children in California were seronegative. Serostatus varied regionally and by demographic group.

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  1. Version published to 10.1093/ofid/ofac246
  2. ScreenIT

    SciScore for 10.1101/2021.12.09.21267565: (What is this?)

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

    Table 1: Rigor

    Ethicsnot detected.
    Sex as a biological variablenot detected.
    RandomizationStudy Design: CalScope is a repeated cross-sectional study using random address-based sampling of households in seven counties in California.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Antibodies
    SentencesResources
    Specimens were tested for both anti-spike and anti-nucleocapsid antibodies using Enable’s ADAP SARS-CoV-2 total antibody assay.
    anti-nucleocapsid
    suggested: None
    Instead, we used self-reported vaccination status, anti-nucleocapsid, and anti-spike antibody results, to classify participants into 4 mutually exclusive serostatus categories: 1) Seronegative: negative nucleocapsid test and negative spike test regardless of self-reported vaccination status; 2) Prior Infection Only: positive nucleocapsid test AND negative spike test OR (positive nucleocapsid test OR positive spike test) AND self-reported not having received any doses of a COVID-19 vaccine; 3) Infected and Vaccinated: Positive nucleocapsid test AND positive spike tests AND self-reported at least 1 dose of any COVID-19 vaccine; and 4) Vaccinated only: Negative nucleocapsid test AND positive spike test AND self-reported at least 1 dose of any COVID-19 vaccine.
    anti-nucleocapsid,
    suggested: None
    anti-spike
    suggested: (GeneTex Cat# GTX632604, RRID:AB_2864418)

    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 found bar graphs of continuous data. We recommend replacing bar graphs with more informative graphics, as many different datasets can lead to the same bar graph. The actual data may suggest different conclusions from the summary statistics. For more information, please see Weissgerber et al (2015).

    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 10.1101/2021.12.09.21267565v1 on medRxiv