Source: Calculated from NY Times Github COVID data repository, data reported through 1/28/2021.
I’m going to do one more post on herd immunity and vaccination. But this is a very positive post. The point is, vaccinations at the current rate should vastly speed up the end of the U.S. third wave of COVID.
That’s really not obvious, is it? Conventional wisdom is that vaccinations will help us get this under control many months from now. But that conventional wisdom springs from a fundamental misunderstanding of herd immunity. It springs from the thoughtless repetition of “70% required for herd immunity”,without realizing that’s for herd immunity in isolation, with no other COVID hygiene measures in place.
By contrast, as long as we continue masking/distancing/limiting, infections alone have already brought us near or past the point of what I call “remission” herd immunity. (See e.g., Post #982). The fraction of the population that is immune via infection is roughly enough to drive the viral replication factor (R) below 1.0. Again, as long as we continue masking/distancing/limiting.
The implication is that newly-vaccinated individuals aren’t moving us slowly in the direction of some far-off target. They are moving us well past the level required to get viral replication below 1.0. Right now. And though the magic of leverage and compounded growth rates, every percent of the population immunized has a huge impact on the speed at which the third wave recedes.
How huge? Roughly speaking, at current rates, by my calculation below, day-for-day. We’re currently vaccinating about 1M per day. Every 3M persons vaccinated brings the date of the end of the third wave forward by roughly three days.
All bets are off once the new COVID-19 variants become prevalent. But my contention is that we can get the existing variant under control in short order, just by maintaining COVID hygiene and maintaining the current rate of vaccinations.
Details follow. Continue reading Post #984: Herd Immunity V: Rapid end of the U.S. 3rd wave of COVID via vaccination.