Does exercise improve the effectiveness of COVID vaccination?

Introduction

This week’s note has been work-in-progress for a couple of months. It involved correspondence with the lead author and every time I have returned to it, I’ve had further thoughts to explore.

I follow the British Journal of Sports Medicine on twitter, as I have written articles published in that journal in the past. On 26th October 2022, I happened to notice a tweet asking, “Does regular #PhysicalActivity improve the protective effect of the #COVID19 vaccine?” (Ref 1). My first thought was “I expect that regular physical activity improves COVID outcomes generally; I wonder how the effect of two things can be separated.”

The paper was called “Association between regular physical activity and the protective effect of vaccination against SARS-CoV-2 in a South African case–control study” (Ref 2). It was written by Collie et al.