Only one thing is clear about our immune system: it's extremely complex and even after a century of prodding it, we still don't know it well enough to prod it in targeted ways and know what to expect.<p>Especially, suppressing the immune system is always dicey, since its not just one variable you tune up or down. However, there _is_ a magic bullet of sorts out there, Intravenous immunoglobulin (IVIG).<p>IVIG is just concentrated antibodies made from plasma of thousands of donors. Its original use case was to clear out a patients antobodies to suppress any antibody-mediated autoimmune response, but turns out IVIG can have global immunosuppressive effects through other mechanisms as well. Importantly, it's very "benign" - almost no known side effects, and your general immunity is still left intact. This has led to extensive use of this drug off-label for anything dealing with excessive immune responses.<p>The more and more I think and look, the more I'm convinced IVIG might help worsening covid patients. Indeed, a case study from China suggests it can be beneficial (3 of 3 very sick patients fully recovered) but of course a proper study is needed (IVIG is quite possibly the worst drug to try and ramp up production). On the other side, a pre-covid trial of IVIG on ARDS patients (already on EMCO) showed no effect, though I personally felt the study was too broad. More studies are also needed, because I'm sure any _new_ IVIG made, since it pools thousands of patients' plasma, is bound to have anti-covid antibodies as well, and this could have some potentially dangerous effects as well (Antibody-Dependent Enhancement). But I'm still cautiously optimistic and am hoping to write to some experts after gathering more data to see what they think.