Offtopic: This is super, super nitpicky, but the Tildes tag
coronaviruses.covid19isn't medically or epidemiologically accurate. A coronavirus is a family of similar RNA viruses, which includes the viruses which causes SARS and MERS. The specific coronavirus at the epicentre of this pandemic is SARS-CoV-2, which causes COVID-19, which is the disease caused by having the virus—COVID-19 isn't the name of the virus itself. This is separate still from the outbreak/phenomenon itself, which wikipedia has called "2019-2020 coronavirus outbreak".
So effectively the tag syntax is
[virus family].[disease]which is a bit weird. I'd probably would have gone for
[virus family].[virus], i.e.
coronaviruses.sarscov2. If you really wanted, you could tag the disease further down the chain to separate discussions on the virology/genetics/medicine from the human factors:
coronaviruses.sarscov2.covid19but that's getting a bit too verbose, probably (yes, this is coming from the same person who argued nested tags should usually be avoided, har har).
Pragmatically, all this doesn't matter all that much I guess, I'm still using the tag as it appears widely accepted now, I just wanted to talk to the void about it. It's also just interesting in general.
Finally, I would just like to point out that we were previously using a tag of just
coronavirus, but that was later changed to