New COVID-19 cases continue to fall in the U.S. We’re now down to 74 new cases per 100K population per day. The 7-day rate of decline is 44%, not materially different from yesterday’s 45%.
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 2/9/2022, 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
My gut reaction to today’s new data is that we’d passed the point of most rapid descent, and that the rate of decline will now begin to taper off, as we have seen in other countries. As far as I can tell, there is no objective information to support that.
Here are the ten states that have led the way in the U.S. Omicron wave, plotted in logs so that a constant percentage decline shows as a straight line. If the ends of those lines are bending toward flat, it’s a pretty subtle effect so far.
If there is a dark cloud on the near-term horizon, it’s the BA.2 variant (a.k.a., son-of-Omicron). The CDC “Nowcast” projection pegs this at 3.6% of all U.S. cases, as of the week ended 2/5/2022.
Source: CDC COVID data tracker, accessed 2/9/2022.
You might reasonably say, what’s the big deal? BA.2 doesn’t appear to be any more virulent than Omicron, but it is more easily transmitted. Original estimates were that it was about 50% more transmissible than Omicron, but more recent estimates put it closer to one-third more infectious than Omicron (reference). Results from both Denmark and the U.K. appear to agree on that figure (reference). If it becomes the prevalent strain, that will result in just so many more infections, all other things equal, and slow down our presumed “return to normalcy”.
Well worth noting, the CDC “Nowcast” model shows this strain’s share tripling every week. On the one hand, you have to take that with a grain of salt, given the small numbers and the uncertainties involved. On the other hand, if those projections are right, and accounting for the timing of the CDC data (that 3.6 figure would have been reached somewhere around 2/2/2022, BA.2 would be come the dominant strain in the U.S. approximately 2/19/2022, or ten days from today. But weigh that fear-mongering against the observation that the growth of BA.2 has been all over the map, in various European countries, and that no country actually saw its share of BA.2 grow that rapidly. My guess, based on European growth rates, is that this preliminary “Nowcast” estimate likely overstates the true rate of growth.
The fact remains that BA.2 took over Denmark in a matter of weeks, but so far it remains a minor issue in most European countries. Coincidence or not, it’s worth noting that Denmark still hasn’t reached a clear peak in its Omicron wave, despite having started that wave before the U.S. did. Draw what conclusions you will from that sample of one.
Source: Johns Hopkins University via Google Search
Finally, there is a bright side to transitioning from pandemic to endemic with as infectious a variant as possible, as long as that variant is relatively benign. There’s no guarantee what the next new variant will bring. Maybe the next one will be as virulent as Delta, or worse. But that won’t matter unless that new variant is better able to spread better than the reigning champion, which will be either Omicron or son-of-Omicron. The tougher those are to beat, from an infectiousness standpoint, the less likely we are to have some new and possibly far more virulent strain of COVID-19 take over.
It is truly a case of better the devil you know than the devil you don’t. Looks like we will probably be able to deal with Omicron OK. Plausibly we can deal with BA.2 OK. Both owing to their much-reduced infectiousness and the ability of a booster shot to provide significant protection. It’s probably better if we can stick with this variant as our endemic COVID-19, rather than roll the genetic dice and face something new.
