Since I live in the US I don’t have to wonder how effective flu shots are, I can look it up: https://www.cdc.gov/flu/vaccines-work/2019-2020.html https://www.cd

Since I live in the US I don’t have to wonder how effective flu shots are, I can look it up: https://www.cdc.gov/flu/vaccines-work/2019-2020.html https://www.cdc.gov/flu/vaccines-work/2019-2020.html Roughly 25-50% based on the strain. Hardly “waste of time” territory. There seems to be some evidence that regular exercise (5ish days per week) reduces the impact of upper respiratory infections (I.e. the common cold) by about that amount, but much less evidence that influenza is similarly affected or affected at all. So for now, if you are choosing between the flu shot and exercise to reduce influenza, the choice is clear. Of course exercise is awesome for other reasons, just maybe not as awesome as a vaccine for influenza.