TLR9 and COVID-19: The effectiveness of TLR9 agonists for the use as vaccine adjuvants has also been suggested (Oberemok et al., 2020).In contrast to the available papers that more broadly focus on TLR3, 7 and 8, the here presented work, elaborates specifically on the role of TLR9 in defense against SARS-CoV-2 and introduces the hypothetical positioning of exaggerated TLR9 activation in severe COVID-19 pathology.