IIUC they had some rats in two rooms, and most of the ill rats were in one room. But they didn't put an amulet of relevant mineral in the cages of one room and use the other room as a control group.

I don't even understand how the rats are related to the discussion about the mineral. Also, it is not clear that the rats got another type or coronavirus.

Is the full paper available online? I was not able to find it.