Presence of Symptoms 6 Weeks After COVID-19 Among Vaccinated and Unvaccinated U.S. Healthcare Personnel

  1. Nicholas M. Mohr
  2. Ian D. Plumb
  3. Karisa K. Harland
  4. Tamara Pilishvili
  5. Katherine E. Fleming-Dutra
  6. Anusha Krishnadasan
  7. Karin F. Hoth
  8. Sharon H. Saydah
  9. Zachary Mankoff
  10. John P. Haran
  11. Melissa Briggs-Hagen
  12. Eliezer Santos León
  13. David A. Talan
  14. the Project PREVENT Network

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Abstract

Importance

Although COVID-19 vaccines protect against infection and severe disease, the role of vaccination in preventing prolonged symptoms in those with subsequent infection is unclear.

Objective

To determine differences in symptoms stratified by prior vaccination reported by healthcare personnel (HCP) 6 weeks after onset of COVID-19, and whether there were differences in timing of return to work.

Design

Nested cohort study within a multicenter vaccine effectiveness study. HCP with COVID-19 between December 2020 and August 2021 were followed up 6 weeks after illness onset.

Setting

Health systems in 12 U.S. states.

Participants

HCP participating in a vaccine effectiveness study were eligible for inclusion if they had confirmed COVID-19 with either verified mRNA vaccination (symptom onset ≥14 days after two doses) or no prior COVID-19 vaccination. Among 681 eligible participants, 419 (61%) completed a follow-up survey approximately 6 weeks after illness onset.

Exposures

Two doses of a COVID-19 mRNA vaccine compared with no COVID-19 vaccine.

Main outcomes and measures

Presence of symptoms 6 weeks after onset of COVID-19 illness and days to return to work after COVID-19 illness.

Results

Among 419 HCP with confirmed COVID-19, 298 (71%) reported one or more COVID-like symptoms 6 weeks after illness onset, with a lower prevalence among vaccinated participants (60.6%) compared with unvaccinated participants (60.6% vs. 79.1%; aRR 0.70, 95% CI 0.58-0.84). Vaccinated HCP returned to work a median 2.0 days (95% CI 1.0–3.0) sooner than unvaccinated HCP (aHR 1.37; 95% CI, 1.04–1.79).

Conclusions

A history of two doses of COVID-19 mRNA vaccine among HCP with COVID-19 illness was associated with decreased risk of COVID-like symptoms at 6 weeks and earlier to return to work. Vaccination is associated with improved recovery from COVID-19, in addition to preventing symptomatic infection.

KEY POINTS

Question

Does vaccination lead to improved recovery of symptoms and return to work following COVID-19?

Findings

In this nested cohort study of healthcare personnel, participants with COVID-19 who had received two doses of a COVID-19 mRNA vaccine were less likely to report symptoms 6 weeks after illness onset than participants with COVID-19 who were unvaccinated. Return to work was sooner if previously vaccinated.

Meaning

Vaccination is associated with improved recovery from COVID-19, in addition to prevention of infection and disease.

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  1. ScreenIT

    SciScore for 10.1101/2022.02.16.22271092: (What is this?)

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

    Table 1: Rigor

    EthicsConsent: 21 All participants provided informed consent prior to participation.
    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: We detected the following sentences addressing limitations in the study:
    Our study has several limitations. First, our follow-up was limited to 6 weeks after symptom onset. While our survey response was robust and we validated test results and vaccinations, the prevalence of symptoms is likely to decay over time and we did not assess longer term effects. We were also not able to determine whether symptoms were caused by SARS-CoV-2 infection, although other evidence indicates that symptoms are usually specific to COVID-19 if reported 6 weeks after illness onset.9 Second, we relied on self-reported symptoms in participants who knew their vaccination status. Many reported symptoms are subjective, leaving open the possibility that vaccinated participants had more confidence that their symptoms would resolve quickly. It is also possible that symptom severity affected response rates, although our findings were similar after excluding symptoms that were rated as mild by participants. Third, our study period precluded analysis of booster doses, which are now recommended for adults in the United States.34 It is possible that booster doses might provide additional protection against symptoms after initial COVID-19. Our analysis was also limited to infections before introduction of the Omicron variant. Finally, there could be unmeasured differences between those vaccinated and unvaccinated that predispose some participants to having persistent symptoms or returning to work more quickly. We attempted to account for some of these factors in our regression mode...

    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 10.1101/2022.02.16.22271092 on medRxiv