Yeah, there are lots of interesting cases where things don't pass from one person to another, but I think how often they do is more instructive. We are surrounded by germs all the time & it is generally the case that things don't get us most of the time. But a cold just went through a number of people at my grandfather's assisted living facility & then my parents who visit him every day got it, & then I got it from them even though I haven't been to see my grandad in a few weeks. So it just kinda makes sense that things are spreading through interaction of some sort, even if succeptibility differs from person to person. Ivermectin which has immediately knocked out syptoms for some things, did very little this time. Which makes me think the explanation about how it prevents replication or maybe the idea of replication itself is nonsense. It does something for some things, so there must be different mechanisms of infection. This one seemed completely isolated to my sinuses & upper respiratory system. My throat hurt & then my nose ran & then for a day or so all of the sinus cavities in my face seemed to hurt, even my ears. But it hasn't really caused much of a reaction from the rest of my body.