This is a fascinating analysis of COVID’s two-month cycle, with the Delta variant following a similar pattern to the first outbreaks. (Apologies for formatting wonkiness — cutting and pasting NYT articles doesn’t always work well.)
A testing site in Auburndale, Fla., last month.Octavio Jones for The New York Times
Has the Delta-fueled Covid-19 surge in the U.S. finally peaked?
The number of new daily U.S. cases has risen less over the past week than at any point since June, as you can see in this chart:
The New York Times
There is obviously no guarantee that the trend will continue. But there is one big reason to think that it may and that caseloads may even soon decline.
Since the pandemic began, Covid has often followed a regular — if mysterious — cycle. In one country after another, the number of new cases has often surged for roughly two months before starting to fall. The Delta variant, despite its intense contagiousness, has followed this pattern.
After Delta took hold last winter in India, caseloads there rose sharply for slightly more than two months before plummeting at a nearly identical rate. In Britain, caseloads rose for almost exactly two months before peaking in July. In Indonesia, Thailand, France, Spain and several other countries, the Delta surge also lasted somewhere between 1.5 and 2.5 months.
* Between February and July 2021, depending on the country.The New York Times
And in the U.S. states where Delta first caused caseloads to rise, the cycle already appears to be on its downside. Case numbers in Arkansas, Florida, Louisiana, Mississippi and Missouri peaked in early or mid-August and have since been falling:
The New York Times
Two possible stories
We have asked experts about these two-month cycles, and they acknowledged that they could not explain it. “We still are really in the cave ages in terms of understanding how viruses emerge, how they spread, how they start and stop, why they do what they do,” Michael Osterholm, an epidemiologist at the University of Minnesota, said.
But two broad categories of explanation seem plausible, the experts say.
One involves the virus itself. Rather than spreading until it has reached every last person, perhaps it spreads in waves that happen to follow a similar timeline. How so? Some people may be especially susceptible to a variant like Delta, and once many of them have been exposed to it, the virus starts to recede — until a new variant causes the cycle to begin again (or until a population approaches herd immunity).
The second plausible explanation involves human behavior. People don’t circulate randomly through the world. They live in social clusters, Jennifer Nuzzo, a Johns Hopkins epidemiologist, points out. Perhaps the virus needs about two months to circulate through a typically sized cluster, infecting the most susceptible — and a new wave starts when people break out of their clusters, such as during a holiday. Alternately, people may follow cycles of taking more and then fewer Covid precautions, depending on their level of concern.
Whatever the reasons, the two-month cycle predated Delta. It has repeated itself several times in the U.S., including both last year and early this year, with the Alpha variant, which was centered in the upper Midwest:
The New York Times
In a few countries, vaccination rates have apparently risen high enough to break Covid’s usual two-month cycle: The virus evidently cannot find enough new people to infect. In both Malta and Singapore, this summer’s surge lasted only about two weeks before receding.
We want to emphasize that cases are not guaranteed to decline in coming weeks. There have been plenty of exceptions to the two-month cycle around the world. In Brazil, caseloads have followed no evident pattern. In Britain, cases did decline about two months after the Delta peak — but only for a couple of weeks. Since early August, cases there have been rising again, with the end of behavior restrictions likely playing a role. (If you haven’t yet read this Times dispatch about Britain’s willingness to accept rising caseloads, we recommend it.)
In the U.S., the start of the school year could similarly spark outbreaks this month. The country will need to wait a few more weeks to know. In the meantime, one strategy continues to be more effective than any other in beating back the pandemic: “Vaccine, vaccine, vaccine,” as Osterholm says. Or as Nuzzo puts it, “Our top goal has to be first shots in arms.”
Do you ever get to the point that life has gotten so far away from you that you don’t even know how to begin to make excuses?
That’s how blogging has been for me these past couple of weeks. A combination of factors that I rationally know are out of my control but are nonetheless stressful, plus long lists of specific things that need to be done, overlaid with general anxiety about world issues such as the weather and that damn impeachment trial. (Seriously — how could any sentient being think 45’s behavior was anything but inexcusable?!) But that one, at least, is in the rearview mirror for now.
I know this is a first world problem, so I apologize in advance.
Dear Husband (DH) and I are in the midst of renovating our soon-to-be-one-and-only-house, which is rapidly being gutted. This is all good news, though it means we are renting a townhome/apartment in another location and need to drive out periodically to pick up mail and make sure there are no contractors lying insensate under a random beam.
Meanwhile, we are trying with no success to date to get on a Covid vaccination schedule. We have signed up in both of the counties where our house and rental are and neither has resulted in an appointment since the state has nowhere near enough supplies for everyone who wants to get it.
On the good news front, our Texas house went under contract within a day of our lovely realtor — who is DH’s oldest daughter — notifying a few agents that we were preparing to sell it. Everything would be proceeding smoothly if it weren’t for, oh, deadly ice storms, massive amounts of snow, power outages, etc. We’re thankful not to be living there but worry about friends and family who are coping with this.
Selling the house also means having someone else pack and ship it. Anxiety-producing because a) we have a lot of things we hope to sell or donate and can’t manage this ourselves, and b) we have to relinquish all fantasies of control over the specifics of the process. I’m trying to adopt the attitude that “stuff is just stuff” and if something gets lost or broken we will replace it. But this is not helping me sleep at night… I’m not counting sheep, I’m counting boxes.
I guess, like all of us, I have to put my faith in whatever powers-that-be may exist, know that we will eventually be on the other side of pandemic-related stress, and just hunker down while managing the few small aspects that are within my control.
If anyone has any good tips for patience after this year of endless upheaval, please share!