Furthermore, we observed that this lead SNP rs1131543-A significantly regulated the expression of two genes: TUFM and SPNS1. These genes are involved in infectious disease pathways and have been implicated as host factors facilitating SARS virus entry into lung tissue,42,43 further supporting that the relationship between the host response to COVID-19 vaccine and susceptibility and severity of COVID-19. This evidence concerns the gene SPNS1 and COVID-19.