Similar viral loads in Omicron infections regardless of vaccination status

  1. Yosuke Hirotsu
  2. Makoto Maejima
  3. Masahiro Shibusawa
  4. Yume Natori
  5. Yuki Nagakubo
  6. Kazuhiro Hosaka
  7. Hitomi Sueki
  8. Hitoshi Mochizuki
  9. Toshiharu Tsutsui
  10. Yumiko Kakizaki
  11. Yoshihiro Miyashita
  12. Masao Omata

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Abstract

Background

Although SARS-CoV-2 booster vaccinations are underway, breakthrough infections with Omicron variants are occurring. This study analyzed associations between Omicron sublineage (BA.1.1 and BA.2) viral load and vaccination history.

Methods

Viral loads in nasopharyngeal swabs were evaluated by quantitative real-time PCR, and the virus strain was evaluated by whole-genome analysis or TaqMan assay.

Results

A total of 611 patients positive for an Omicron SARS-CoV-2 variant were included; 199 were unvaccinated, 370 had received two vaccine doses, and 42 had received three doses. Similar viral loads and Ct values of BA.1.1 and BA.2 were detected regardless of vaccination history. No correlations between age and BA.1.1 and BA.2 viral load were observed.

Conclusion

Omicron-infected patients who had received a third vaccine dose had viral loads similar to patients with two doses or who were unvaccinated.

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  1. ScreenIT

    SciScore for 10.1101/2022.04.19.22274005: (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.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Statistical analysis: All statistical tests and visualizations were performed with R (v4.1.1) or RStudio (http://www.r-project.org/).
    RStudio
    suggested: (RStudio, RRID:SCR_000432)
    http://www.r-project.org/
    suggested: (R Project for Statistical Computing, RRID:SCR_001905)
    Plotting in R also made use of the ggplot2 (v3.3.5), dplyr (v1.0.7), tidyr (v1.1.3), patchwork (v1.1.1), gtsummary (v1.5.2), and flextable (v.0.7.0) packages.
    ggplot2
    suggested: None

    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 had limitations. First, it did not assess the amount of culturable, viable virus, so it is unknown whether the detections represented infectious virus. Second, it did not take into account the time since vaccination, and there may have been variation in antibody titers. Third, there may be bias because the number of vaccine doses differed with age. Therefore, further analysis with a larger sample size is needed. In summary, individuals infected with the Omicron variant might still be able to produce infectious virus even if they have received a booster vaccination. Therefore, isolating patients with a breakthrough infection could help mitigate the spread of SARS-CoV-2.

    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 10.1101/2022.04.19.22274005v1 on medRxiv