15 September

Fewer people seem to be dying of Covid. (Always a critical sign a pandemic may be waning.) There's a theory that wearing masks is giving people immunisation against Covid, by restricting the dose of virus they inhale. Called variolation (giving somebody a 'small' dose of live virus, it was a technique used before vaccination). So they only get mild illness and become immune. There's another possibility though, that nobody will talk about. Pathogens drop in virulence when people isolate from one another. Like in lockdowns. Where there are large gatherings, historically not only do more people get infected, but they also get much sicker - the pathogen grows in virulence. This makes sense, because a pathogen that has easy access to a new host doesn't have to worry about making the one they're in very sick.