One of the biggest week to week drops on record, from 98,000 cases last Thursday, to 68,000 cases today. Cases are falling fast. In addition, positivity rate in the US has fallen to a 7 day moving avg of 5.2%, a steady fall from a winter peak of 13.6% last month.
Cases over Thursdays
1/7 279,000
1/14 234,000
1/21 195,000
1/28 166,000
2/3 114,000
2/10 98,000
2/17 68,000
I think this is largely due to seroprevalence, but the vaccine is also definitely playing a major part.