Oh dear! As viruses become more transmissible they often become less virulent. Not always and there is no evidence that this variant is more or less virulent. (Actually it's not the deaths that are the problem. It's those in hospital for a long time and unwell for a long time after.)
And given that the US population is about 5x ours, their current case rate us at least as high as ours, assuming their data collection is as accurate as ours.
And the Antarctic cases were arose during the annual crew change at the Chilean base. Clearly the incoming crew ought to have been quarantined.
And I used to work in a Virology department.