Booster protection against Omicron infection in a highly vaccinated cohort

  1. Caroline G. Tai
  2. Lisa L. Maragakis
  3. Sarah Connolly
  4. John DiFiori
  5. Leroy Sims
  6. Eleanor Adams
  7. Deverick J. Anderson
  8. Michael H. Merson
  9. David D. Ho
  10. Yonatan Grad
  11. Christina DeFilippo Mack

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Abstract

Background

Evaluation of COVID-19 vaccine booster effectiveness is essential as new variants of SARS-CoV-2 emerge. Data support the effectiveness of boosters in preventing severe disease and hospitalization; however, the real-world impact on reducing incident SARS-CoV-2 infections across specific variants is not yet clear.

Objectives

Assess the impact of COVID-19 boosters on protection against SARS-CoV-2 infection in a real-world setting from a highly vaccinated (99%) population curated from a linked database with test results, vaccination history, patient demographics, and genomic sequencing information from the National Basketball Association (NBA).

Methods

In this population, 1,613 fully vaccinated staff and players (median age 34.5 years, 88% male) who tested at least once between 1 December 2021 and 5 January 2022, were analyzed. Individuals were tested at the time of reporting any symptom, regardless of severity, after known exposure per self-report or contact tracing and/or during enhanced surveillance. Boosted individuals (n=1260) were compared to fully vaccinated and booster eligible individuals (n=162), defined as 2 months post-JNJ-78436735 or 5-months post-second dose of mRNA vaccine. Individuals not yet eligible for a booster and those who recovered from COVID-19 between 1 November and 30 November, 2021 (n=25) were examined in secondary analyses but excluded from the primary comparison. Individuals who were not fully vaccinated (n=27) or who received a booster within 14 days during or prior to the observation period (n=916) were excluded.

Results

In this closely monitored population, fully vaccinated booster-eligible individuals were 2.6 times more likely (RR = 2.6, 95% CI: 2.2 to 3.0, p<0.0001) to have a confirmed COVID-19 infection than boosted individuals. Secondary analysis including non-boosted individuals with recent vaccination or recent SARS-CoV-2 infection found that non-boosted individuals were at greater risk of infection compared with boosted individuals (RR = 2.1, 95% CI: 1.8 to 2.4, p<0.001). Results were similar when stratified by primary vaccination type with overlapping confidence intervals. No hospitalizations or deaths were observed in this cohort. Genetic sequencing confirmed 93% of infections to be Omicron (among n=330 sequenced).

Conclusions

These results highlight the protective benefit of boosters against incident SARS-CoV-19 infection, not only for severe symptoms and death. Assessment of booster effectiveness remains vital for COVID-19 vaccines as new variants of SARS-CoV-2 emerge, as there is still uncertainty around performance in real-world settings. These data are needed to convince the general public that boosters remain effective at preventing in the spread of COVID-19.

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  1. ScreenIT

    SciScore for 10.1101/2022.02.24.22271347: (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

    No key resources detected.

    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

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  2. Version published to 10.1101/2022.02.24.22271347 on medRxiv