Originally Posted by
MultiVerse
TL;DR: The numbers are relative to a peak, there's still lots of new cases. The peak occurred because with each holiday (Halloween, Thanksgiving, Hanukkah, Christmas, and New Year’s) more people mixed together causing cases to explode. It's the old exponential growth story. On average, an infected person infects between 2-and-5 other people until there's a conflagration. Now with holiday season behind us and vaccines in front of us people at the margins are behaving more cautiously.
The longer version:
Even though caseloads and hospitalizations are falling the numbers are relative to a peak. There's still a lots of area under the curve, still lots of infection and hospitalizations. There are probably several reasons for the trend ranked in order of significance:
1 - A post holiday plateau
2 - More caution due to the imminent availability of vaccines
3 - Awareness of mutated variant further reinforcing caution
4 - Population-level immunity
Cumulative COVID deaths still remain roughly proportional to seroprevalence. By most estimates the death rate is roughly .5% and the U.S. seroprevalence number is roughly +100,000,000.
If 60% are essentially immune by behaving cautiously, while the other 40% have lots of contacts. And if 80% of that high-contact group has been infected — a third (~33%) of the population has seroprevalence — there might be some herd effects among high contact groups but not the community as a whole.
The good news is the high-mixing group has a higher rate of acquired immunity while the cautious group will soon have a high rate of vaccinated immunity.