@article {Colliebjsports-2022-105734, author = {Shirley Collie and Robin Terence Saggers and Rossella Bandini and Lizelle Steenkamp and Jared Champion and Glenda Gray and Linda-Gail Bekker and Ameena Goga and Nigel Garrett and Jon Patricios}, title = {Association between regular physical activity and the protective effect of vaccination against SARS-CoV-2 in a South African case{\textendash}control study}, elocation-id = {bjsports-2022-105734}, year = {2022}, doi = {10.1136/bjsports-2022-105734}, publisher = {British Association of Sport and Excercise Medicine}, abstract = {Background Both vaccination and physical activity have been shown to independently decrease the likelihood of severe COVID-19 infection.Objective To assess the association between regular physical activity and vaccination against COVID-19 among healthcare workers.Methods A test negative case{\textendash}control study design was used to estimate the risk of having an associated COVID-19-related hospital admission, among individuals who were unvaccinated compared with those who were fully vaccinated with Ad26.COV2.S (\>28 days after a single dose). 196 444 participant tests were stratified into three measured physical activity subgroups with low, moderate and high activity, to test the hypothesis that physical activity is an effect modifier on the relationship between vaccination and hospitalisation.Results Vaccine effectiveness against a COVID-19-related admission among vaccinated individuals within the low activity group was 60.0\% (95\% CI 39.0 to 73.8), 72.1\% (95\% CI 55.2 to 82.6) for the moderate activity group, and 85.8\% (95\% CI 74.1 to 92.2) for the high activity group. Compared with individuals with low activity levels, vaccinated individuals with moderate and high activity levels had a 1.4 (95\% CI 1.36 to 1.51) and 2.8 (95\% CI 2.35 to 3.35) times lower risk of COVID-19 admission, respectively (p value \<0.001 for both groups).Conclusions Regular physical activity was associated with improved vaccine effectiveness against COVID-19 hospitalisation, with higher levels of physical activity associated with greater vaccine effectiveness. Physical activity enhances vaccine effectiveness against severe COVID-19 outcomes and should be encouraged by greater public health messaging.No data are available.}, issn = {0306-3674}, URL = {https://bjsm.bmj.com/content/early/2022/10/30/bjsports-2022-105734}, eprint = {https://bjsm.bmj.com/content/early/2022/10/30/bjsports-2022-105734.full.pdf}, journal = {British Journal of Sports Medicine} }