This is a common problem with COVID-19 threads on HN now. Happened to me several times in the past weeks. It's interesting but also very concerning just how
large the knowledge gap has become between people who still support the public health restrictions and everyone else. Almost any fact you present, regardless of how basic or well known you think it is, will run into someone who thinks it's wild and crazy and has never encountered it before. That's true even if it's been admitted in public by the people who literally run the public health response!
The cause seems to be aggressive filter bubbling. We see it above too - there are highly upvoted people saying nothing more than "it can't be true, I don't believe it, it must be a right wing conspiracy". Any information that undermines government narratives just gets mentally erased, causing a distressed reaction of "that claim is CRAZY" to almost any attempt to discuss known data or facts.