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Association between regular physical activity and the protective effect of vaccination against SARS-CoV-2 in a South African case–control study
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  • Published on:
    Does exercise really boost immune response to Covid-19 Vaccine ?
    • Prof Satish Kumar Gupta, Clinical Assistant Professor of Medicine GS Medical College Uttar Pradesh India Author of Book Journey of Covid in India -A Doctors' Perspective
    • Other Contributors:
      • Sakshi Gupta, Senior Resident

    There is absolutely no doubt that physical activity is a beautiful phenomenon. In the above study, the study is fair to the extent that those subjects who regularly exercised had lesser hospitalisations. Here both reason and effect exist, but can a direct causal relationship be established between the two?
    Can it be inferred beyond doubt that "the vaccine prevented complications of Covid-19 because exercise strengthened the immune response? The possibility of such a remarkable effect in the short term is pretty unlikely. And all the more, such findings can't be generalised to a larger population.

    Authors seem to be ignoring a hidden confounder affecting the validity of the study, and this confounder is 'frailty'. Simply those doing less exercise were unable to do so because they were frail. And obviously, frailty can be present independent of comorbidities like DM, heart failure or obesity, which were evenly matched between the high and low-exercise groups.

    So, the correct conclusions will likely differ if this confounder is considered. one may not forget that 'Correlation, even if present in a statistically significant portion, may not amount to causation.

    The study might prompt some frail people or even morbidly obese people to engage in heavy exercise soon after the vaccination despite muscle aches and fever (common side effects of the Covid-19 vaccines). And these might have disastrous consequences. So the wo...

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    Conflict of Interest:
    None declared.