SARS-CoV-2 Vaccine Alpha and Delta Variant Breakthrough Infections Are Rare and Mild but Can Happen Relatively Early after Vaccination

  1. Jelissa Katharina Peter
  2. Fanny Wegner
  3. Severin Gsponer
  4. Fabrice Helfenstein
  5. Tim Roloff
  6. Rahel Tarnutzer
  7. Kerstin Grosheintz
  8. Moritz Back
  9. Carla Schaubhut
  10. Sabina Wagner
  11. Helena M. B. Seth-Smith
  12. Patrick Scotton
  13. Maurice Redondo
  14. Christiane Beckmann
  15. Tanja Stadler
  16. Andrea Salzmann
  17. Henriette Kurth
  18. Karoline Leuzinger
  19. Stefano Bassetti
  20. Roland Bingisser
  21. Martin Siegemund
  22. Maja Weisser
  23. Manuel Battegay
  24. Sarah Tschudin Sutter
  25. Aitana Lebrand
  26. Hans H. Hirsch
  27. Simon Fuchs
  28. Adrian Egli

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Abstract

(1) Background: Some COVID-19 vaccine recipients show breakthrough infection. It remains unknown, which factors contribute to risks and severe outcomes. Our aim was to identify risk factors for SCoV2 breakthrough infections in fully vaccinated individuals. (2) Methods: We conducted a retrospective case-control study from 28 December 2020 to 25 October 2021. Data of all patients with breakthrough infection was compared to data of all vaccine recipients in the Canton of Basel-City, Switzerland. Further, breakthrough infections by Alpha- and Delta-variants were compared. (3) Results: Only 0.39% (488/126,586) of all vaccine recipients suffered from a breakthrough infection during the observational period, whereof most cases were asymptomatic or mild (97.2%). Breakthrough infections after full vaccination occurred in the median after 78 days (IQR 47-123.5). Factors with lower odds for breakthrough infection were age (OR 0.987) and previous COVID-19 infection prior to vaccination (OR 0.296). Factors with higher odds for breakthrough infection included vaccination with Pfizer/BioNTech instead of Moderna (OR 1.459), chronic disease (OR 2.109), and healthcare workers (OR 1.404). (4) Conclusions: Breakthrough infections are rare and mild but can occur early after vaccination. This implies that booster vaccination might be initiated earlier, especially for risk groups. Due to new variants emerging repeatedly, continuous monitoring of breakthrough infections is crucial.

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  1. Version published to 10.3390/microorganisms10050857
  2. ScreenIT

    SciScore for 10.1101/2021.12.23.21268324: (What is this?)

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

    Table 1: Rigor

    EthicsIACUC: Ethics: The study has been approved by the local ethical committee (EKNZ 2020-00769 and 2021-00774).
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Briefly, we used the Arctic protocol on a NextSeq 500 platform (Illumina), followed by the GOVGAP pipeline to determine the viral lineage as previously described 38,39.
    Arctic
    suggested: (ARCTIC, RRID:SCR_005989)
    GOVGAP
    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:
    Limitations: Our study has several important limitations. During the study timeframe, diagnostic and screening tests on SARS-CoV-2 for vaccinated individuals were only recommended by the Federal Office of Public Health (FOPH) when symptoms occurred or when the vaccinated individual lived in the same household as an individual tested positive for SARS-CoV-2. Therefore, although all positive test results are being reported to the FOPH, missing data on breakthrough infections in e.g., asymptomatic patients is possible. Due to different reporting systems, information regarding immunosuppression in the control population is only available for individuals vaccinated in the Corona Vaccination Centre for the Canton of Basel-City and not for individuals vaccinated in other sites such as pharmacies or hospitals. Because only vaccinating institutions in Switzerland are obligated to report to the Swiss COVID-19 vaccination register, individuals with residence in the Canton of Basel-City vaccinated outside of Switzerland are not recorded in the database. Accordingly, individuals vaccinated with ChAdOx1-S only appear in the case group. We included a relatively small number of sequenced cases with breakthrough infection - sequencing was available only for a subset of PCR confirmed cases (approximately 5-10%) of all cases are part of a nation wide surveillance program. Although we have not sequenced all strains, it is unlikely that we have missed a substantial dominant new lineage causing br...

    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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  3. Version published to 10.1101/2021.12.23.21268324v1 on medRxiv