GSTP1 and COVID-19: In addition to confirming that the course of COVID-19 is statistically significantly milder in vaccinated patients than in unvaccinated patients in real-life clinical practice, we also observed that factors associated with the severity of COVID-19 differed in the study groups, and only in previously vaccinated patients was the GSTP1 Ile/Val genotype found to be associated with higher risk of developing a severe form of the disease.