How much of a threat is Delta in the US?

The delta variant has been increasing in terms of percentage of cases in recent weeks in the US. However, overall number of cases have been declining during the same time period. So that raises the question of whether delta cases are rising in an absolute sense.

So I pulled out the case numbers for the two week windows that we have percentage data for the variants, and found absolute numbers of delta cases. I found that delta is indeed increasing in terms of absolute numbers in the US, although not very quickly.

I then wondered how the US numbers compare to the UK numbers. Interestingly, the delta variant was introduced to the UK at about the same time it was introduced to the US. However, it is spreading a LOT faster in the UK.

In this graph, red is for alpha cases, blue for delta cases. Solid lines are for the US, dashed lines are for the UK. In order to compare the two countries, I standardized cases per million total population of each country.

This is good news, at least for the US. I think a lot of people are assuming that it's going to take off here at the same rate it has in the UK, and at least so far, its growth rate is not even close.

Source for case numbers: Worldometer
Source for variant percentages: Regeneron covid dashboard.