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Impact of Pre-Infection COVID-19 Vaccination on the Incidence and Severity of Long COVID: A Retrospective Case–Control Study, 2025, Barado et al.

Discussion in 'Long Covid research' started by SNT Gatchaman, Feb 13, 2025.

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  1. SNT Gatchaman

    SNT Gatchaman Senior Member (Voting Rights)

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    Impact of Pre-Infection COVID-19 Vaccination on the Incidence and Severity of Long COVID: A Retrospective Case–Control Study
    Elena Barado; Silvia Carlos; Laura Moreno-Galarraga; Fares Amer; Nicolás Escrivá; María Gabriela Torres; Gabriel Reina; Alejandro Fernandez-Montero

    Long COVID is an emerging condition with an important impact on the quality of life of affected individuals. This study aims to analyse the association between complete vaccination prior to SARS-CoV-2 infection and the subsequent development of long COVID, including its symptoms and their frequency through a retrospective case–control study.

    Cases included participants with long COVID, while controls were participants without long COVID but who had a SARS-CoV-2 infection. Data were collected through a self-reported survey.

    The study demonstrates a significant association between vaccination and a lower incidence of long COVID, adjusted for sex, age, university education, body mass index, physical activity, race, tobacco use, alcohol intake, adherence to Mediterranean diet, previous illness, flu vaccination, health care worker, high-risk COVID worker and sleep hours and sedentarism (OR 0.49, CI 95% 0.28–0.87). Furthermore, there is a statistically significant association between vaccination and reduced symptoms such as anosmia, dysgeusia, myalgia or arthralgia, as well as a lower overall number, adjusted for the aforementioned variables.

    These findings suggest that the vaccine could be associated not only to a milder course of SARS-CoV-2 infection but also with an improvement in the state of long COVID and its symptoms.

    Link | PDF (Immunology) [Paywall]
     
    SNT Gatchaman, Feb 13, 2025
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  2. Utsikt

    Utsikt Senior Member (Voting Rights)

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    I don’t have access to the paper. Does this mean that they found that vaccination after getting LC improved certain LC symptoms?
     
    Utsikt, Feb 13, 2025
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  3. John Mac

    John Mac Senior Member (Voting Rights)

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    I took it to mean vaccination before getting infected resulting in LC

    "This study aims to analyse the association between complete vaccination prior to SARS-CoV-2 infection and the subsequent development of long COVID"
     
    John Mac, Feb 13, 2025
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  4. Utsikt

    Utsikt Senior Member (Voting Rights)

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    In isolation, I read it as post-LC-vaccine improves LC. But as you say, the title says pre-LC-vaccine. So I’m confused!
     
    Utsikt, Feb 13, 2025
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  5. Nightsong

    Nightsong Senior Member (Voting Rights)

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    Nightsong, Feb 13, 2025
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  6. Utsikt

    Utsikt Senior Member (Voting Rights)

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    Only pre-LC-vaccine it is.

    Thank you, @Nightsong
     
    Utsikt, Feb 13, 2025
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  7. Peter Trewhitt

    Peter Trewhitt Senior Member (Voting Rights)

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    I am not totally with it today so may be wrong but I took it to mean the study showed that prior vaccination both reduced the likelihood of developing Long Covid and reduced the severity of any Long Covid that developed. However I am not sure how the study design could demonstrate.
     
    Peter Trewhitt, Feb 13, 2025
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  8. SNT Gatchaman

    SNT Gatchaman Senior Member (Voting Rights)

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    SNT Gatchaman, Feb 15, 2025
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  9. Hutan

    Hutan Moderator Staff Member

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    It's a reasonable conclusion to draw, given the way they phrased it. I think it's rather misleading although probably not intentionally so.

    Long Covid is a very loose entity. If people are getting milder Covid-19 infections, then it's not surprising that some are not getting the persistent symptoms that result from severe illnesses. It's still possible that vaccination is not protective against LC ME/CFS.

    It's also possible that there is some other protective factor associated with 'people who get vaccinated' rather than the vaccination itself that wasn't accounted for. People who get vaccinated might be more conscientious and so take better care of their health, more likely to have employers who give them time off when they get sick, more likely to have people who care about them enough to both arrange vaccinations and nurse them when they are sick. On that last point, we so often see Spanish studies that report all the details of their cohorts personal lives - married, single, divorced, widowed or whatever, so it's a bit strange that they didn't adjust for having a 'significant other'.

    Nevertheless, from the abstract, getting vaccinated looks to lower the odds of subsequent persistent symptoms by a lot
     
    Hutan, Feb 15, 2025
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  10. Midnattsol

    Midnattsol Moderator Staff Member

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    An issue I don’t know how could be accounted for is that someone who is vaccinated may be less likely to say their symptoms are related to a covid infection. After all they are vaccinated and so «safe» from harms from covid.
     
    Midnattsol, Feb 15, 2025
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  11. Eleanor

    Eleanor Senior Member (Voting Rights)

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    On the other hand, there are people who don't get vaccinated because they don't believe Covid is dangerous (for people like themselves), so if they go on to have LC-type symptoms they'll be less likely to attribute them to Covid.
     
    Eleanor, Feb 15, 2025
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  12. Utsikt

    Utsikt Senior Member (Voting Rights)

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    Or attributed their LC symptoms to the vaccine
     
    Utsikt, Feb 15, 2025
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