The COVID-19 new case count is unchanged at 39 new cases per 100K population per day. Deaths are still running 350 per day. And for reasons unknown, hospitalizations are now up to 6500 a day.
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 7/28/2022, 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
Other than occasional dips caused by data reporting issues, the state-level data don’t show much of a trend anywhere. Not only is the U.S. new case rate steady, it’s steady in more-or-less every state.
Reinfections
New York remains just about the only place to get consistent data on the reinfection rate for a large population. The last time I looked at that was toward the end of June (Post #1541). Let’s revisit here at the end of July.
Then (June)
Now (July)
Source: Calculated from data from New York State. Read their methods from this page.
Sorry about flipping the scales for the Y-axis around. The important point is that a) most of the current infections are still first infections with COVID-19, and b) reinfections continue to rise. At the end of June, reinfections accounted for 14% of all new cases in New York state, now they are close to 18%.
When I looked at this last month, I could reasonably say that most of the increase was simply due to an increase in the pool of persons with some prior infection. That happened as persons from the large winter Omicron wave “aged into” the reinfection-eligible pool. (The new infection has to be at least 90 days after the prior infection for it to count as a reinfection).
Now that’s not so clear. While there’s still an ongoing increase in the number of people who have had some infection, it isn’t that large. I’d have to guess that this last little uptick in the reinfection rate can plausibly be attributed to the final takeover of the BA.5 and BA.4 strains, which appear to be exceptionally good at reinfecting those with a prior Omicron infection.
In any case, the more I ponder this picture, the less I know.
The question is, why aren’t there even more reinfections than we are currently seeing? The numbers don’t add up.
First, even though the U.S. CDC no longer appears to be doing seroprevalence surveys, it’s a good bet that at least 70% of all adults have had a COVID-19 infection, at this point.
Second, near as anybody can tell, neither prior infection nor vaccination provides much protection against an infection from these latest strains.
When I put those two facts side-by-side, I’d expect reinfections to be — well, if not 70% of all infections, then something much closer to it. Half, maybe?
One possible explanation is that epidemiologists have goofed in their estimate of the protection provided by a prior infection. Maybe you actually get much more protection than they have suggested, suppressing the observed reinfection rate.
But my bet is that people have get blasé about COVID-19 infections once they’ve survived one without incident. People who had no more than a moderate case the first time now know what to expect, and see little need for any formal medical intervention. So while one might consult a doctor the first time around — and get formally tested — for the reinfections, it’s like getting the flu. Unless something goes terribly wrong, most people know what the flu will do and they treat themselves accordingly.
So it’s not that people aren’t getting reinfected. It’s that reinfection cases disproportionately are not getting formally tested. Pure guesswork, but that’s the best guess I’ve got.
