Cliff Diving

It's hard to keep absolute track of the content of these missives, since they're not stored in my beloved RDBMS, but at least by the end of February these missives pondered the odd shape of the Covid infection curve. Why would it look like a witch's hat rather than having a slower decline than rise? What would explain that?

All these months later, David Leonhardt questioned some experts in epidemiology. And guess what? They still don't have an answer yet, either.

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.

Note that at one point, Osterholm allowed as how the next few weeks would be the worst.

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.)

Listen up wannaBePresident Huey Long 2024-sters

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.