CDC says that the Delta variant is now the dominant one in the US

[Ms. Toad]

5. The Delta variant is becoming dominant all over the place because it is so contagious.

So let's say we start out with 10 regular cases of COVID and 1 Delta case.

Delta cases are 1.6 as contagious, so each time the regular cases double - the Delta cases increase by 1.6 x 2

So for 7 cycles of doubling, here's what happens:

10 regular -> 20 regular -> 40 regular -> 80 regular -> 160 regular -> 320 regular -> 640 regular-> 1280
1 Delta -> 3.2 delta -> 10.24 Delta -> 32.768 Delta -> 104.8576 Delta -> 335.5443 Delta -> 1073.742 Delta-> 3435.974

So even though the Delta variant started out at 1/10 of the regular cases - in 7 "doublings" it now has 3 times as many cases as the regular variant had (and the spread between the two will continue to grow)

So - it doesn't take many initial cases to create an incredibly large number of cases in a very short period of time.

And we're not doing ourselves any favors by acting as if the pandemic is over - no one is masking around here (aside from a handful of us who are already vaccinated). And breakthrough cases are at somewhere between 19.2% and 50% as many as cases in the unvaccinated, for the same exposure. I'm not sure I trust the Israeli data yet - but even at the lowest reduction in effectiveness - Delta loves that!

A friend of mine was on a Holland America cruise (the Zaandam - that was delayed going throug the Panama Canal) and got COVID as a parting gift.