OK, there is a South African variant of the COVID-19 virus. It appears that some of the vaccines are less effective against it. The two people in the US that have tested positive for that variant have no connection to each other and have not traveled.
Let’s think that through for a second. Have not traveled and have no connection to each other. Leaves us with two possibilities:
1) they came into contact that are infected but not showing symptoms.
2) The COVID-19 virus is evolving and becoming more dangerous.
I would lay odds on either choice.