NLRP3 and infection: Furthermore, while some reports have shown that SARS-CoV-2 can actively infect primary human monocytes, resulting in NLRP3 activation and IL-1β secretion (20, 85, 86), in the present study we were unable to detect productive infection of primary human HC monocytes by SARS-CoV-2 in vitro (Supplementary Figure 4), although SARS-CoV-2 exposure was sufficient to promote NLRP3-driven IL-1β production.