Among the TSLP SNPs, we did not find any significant associations with COVID-19 severity; however, for IL-33, the homozygous minor genotype of rs3939286 demonstrated a significant association with the severe form of the disease (p = 0.033) with an odds ratio of 0.109 (95% confidence interval 0.14–0.839) indicating an inverse association. Here, TSLP is linked to COVID-19.