Finally, the best responses (p < 0.001 for Nab titers and p = 0.04 for anti-RBD titers, compared with “Naive + 2D”) were observed for convalescent COVID-19 patients vaccinated with one dose of vaccine, where all patients harbored a significant neutralization titer for the four variants and high levels of anti-RBD Abs. This evidence concerns the gene DDX41 and COVID-19.