Risk of SARS-CoV-2 Infection Breakthrough among the Non-Vaccinated and Vaccinated Population in Italy: A Real-World Evidence Study Based on Big Data

  1. Alessandro Perrella
  2. Massimo Bisogno
  3. Angelo D’Argenzio
  4. Ugo Trama
  5. Enrico Coscioni
  6. Valentina Orlando

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Abstract

SARS-CoV-2 infection after vaccination can occur because COVID-19 vaccines do not offer 100% protection. The study aim was to assess duration of vaccination coverage, disease symptoms and type of hospitalization among non-vaccinated and vaccinated subjects to evaluate the vaccination trend over time. A retrospective cohort study was carried out among people testing COVID-19 positive in Campania Region using information from the Health Information System of Campania Region (Sinfonia). Vaccination status was assessed considering: no vaccination, partial vaccination and effective vaccination. Univariate and multivariate logistic regression models were constructed to evaluate the association between ICU admissions caused by COVID-19 and gender, age groups and vaccine type. Vaccine coverage duration trends were investigated using segmented linear regression and breakpoint estimations. Vaccination coverage was assessed by analyzing COVID-19 positive subjects in the 9 months after an effective dose vaccination. A significant risk of hospitalization in the ICU was caused by vaccination status: subjects non-vaccinated (OR: 7.14) and partially vaccinated (OR: 3.68) were 3 and 7 times more at risk of hospitalization, respectively, than subjects effectively vaccinated. Regarding subjects with an effective vaccination, the vaccine’s ability to protect against infection in the months following vaccination decreased. The risk of contracting COVID-19 after vaccination was higher 5 months (β = 1441, p < 0.001) and 7 months (β = 3110, p < 0.001) after administration of an effective dose. COVID-19 vaccines were demonstrated to protect from symptomatic infection by significantly reducing hospitalization risk, and their full protection against SARS-CoV-2 was demonstrated to decrease after 5 months regardless of age, gender or vaccine type.

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  1. Version published to 10.3390/healthcare10061085
  2. ScreenIT

    SciScore for 10.1101/2022.02.22.21266830: (What is this?)

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

    Table 1: Rigor

    EthicsConsent: 14,15 Participant consent was given for the release of all SARS-CoV-2 PCR test results before or after vaccination.
    Sex as a biological variablenot detected.
    Randomizationnot detected.
    Blindingnot detected.
    Power Analysisnot detected.
    Cell Line AuthenticationAuthentication: It is complete and involves data management system that has been validated in previous studies.

    Table 2: Resources

    Software and Algorithms
    SentencesResources
    Nasopharyngeal swabs were collected by trained personnel of Regional Healthcare system and/or authorized and trained territorial laboratory staff.
    Regional Healthcare
    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: 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 10.1101/2022.02.22.21266830 on medRxiv