The count of daily new COVID-19 cases continues to rise across the U.S. We’re now at 16 new cases per 100K population per day. The rate of increase has slowed to about 20 percent per week, down from 25 percent (or so) in the recent past. The Northeast region — which led the way in this secondary Omicron wave — continues to see weekly increases at about half that rate.
Data source for this and other graphs of new case counts: Calculated from The New York Times. (2021). Coronavirus (Covid-19) Data in the United States. Retrieved 4/23/2022, from https://github.com/nytimes/covid-19-data.” The NY Times U.S. tracking page may be found at https://www.nytimes.com/interactive/2020/us/coronavirus-us-cases.html
As you can see, the Northeast region occupies almost all the top slots in the ranking of states by current new case load. By contrast, the bottom of the listing is solidly packed with states in the middle of the country, that is, neither East Coast nor West Coast states.
The CDC came out with new estimates for the new COVID-19 variants on Tuesday. The interesting finding is that the latest-and-most-infectious variant, BA.2.12.1 — isn’t growing very fast. Last week, it accounted for 19% of new cases. (And that estimate, of last week’s number, is unchanged). This week, it accounts for 29%.
Source: CDC COVID data tracker, accessed 4/28/2022
From that, I think we can infer that it’s not hugely more infectious than the current champ, son-of-Omicron (BA.2). We’ve gotten so used to seeing these new variants double their share of cases every week that it’s what — a relief? — to see one whose share only grows 50% per week.
It remains true that the Northeast has the highest new case load, and the Northeast has the highest share of BA.2.12.1 as a fraction of new cases:
But, recall, the Northeast doesn’t have a particularly high current rate of increase in new cases.
Taken all together, that suggests that BA.2.12.1 isn’t a huge threat. All the numbers paint a consistent picture. It’s modestly more infectious than son-of-Omicron (BA.2). But that’s all it is.
An interesting detailed scientific article in Forbes (of all places) provides a clue as to why this isn’t such a huge deal in the U.S. If you get down into the fine detail, this new variant evades the immune system using the same mutation that Omicron used. The implication is that anyone who has antibodies from an Omicron infection will likely have high immunity to this variant. BA.2.12.1 is facing a stiff headwind, in the form of the large fraction of the U.S. population that was infected during the bulk of the Omicron wave.
Meanwhile, new COVID-19 hospitalizations have begun to pick up, but they still lag new cases. The most recent figure on the CDC COVID data tracker is 1800 new hospitalizations per day, up 17% in the past week.
Finally, it remains tough to say, exactly, how fast immunity is fading. All we have is some well-aged observational data from the CDC. Based on that, as of February (for deaths) and March (for any infection), boosters provide strong protection against dying from COVID-19, but very little in the way of preventing you from getting infected with it.
Source: CDC COVID data tracker, accessed 4/28/2022
That’s consistent with the finding that antibodies fade rapidly after the booster dose. It’s the antibodies that give you a rapid immune response and protection against any infection. So you retain protection against severe outcomes, just not against having any infection whatsoever.
