Delta’s demand curve?

The Delta variant of the coronavirus is ferociously contagious. In India more than 2.4 million deaths have been credibly attributed to Delta’s rapid spread in the subcontinent’s so-called “second wave”, extending from April to June 2021.

Delta was also the principal culprit in the United Kingdom’s — well, England’s — pandemic surge between early June and late July. On June 1, 2021, ninety residents of England were hospitalized with covid-related disease. On July 27 this surge apparently peaked with 793 covid-cases in hospital. As of August 10 the number of related deaths was continuing to climb.

Delta has been spreading rapidly in the United States since May. But through most of June Delta was not causing an observable — confirmable — increase in disease. That began to change in late June. Initial disease outbreaks were localized. But since at least June 27, we have seen increasing hospitalizations over wide areas, especially among the Gulf Coast states plus Arkansas, Missouri, and Georgia.

England is roughly the size of Alabama, but has a population double that of Texas (England has about 56 million residents). England has close to a 90 percent vaccination rate for residents 18 and over, compared to about 56 percent of Texans over age 18 or almost 44 percent of residents 18 and older in Alabama. (More.) Comparing the US experience with Delta to that of England is imprecise.

But because inquiring minds want to know, if the US demand curve for Delta is anything like that of England’s, the US won’t achieve nation-wide peak hospitalizations until early September. Given the much larger geography and lower vaccination rates in the United States, I would not be surprised to see an extended rise. And — England’s fairly high plateau for hospitalizations is interesting too (see first chart above).

Delta is much more optimized to humans than earlier variants. What about Lambda? The covid demand curve in Peru, where Lambda has dominated, may suggest what a post-Delta wave could look like.


August 13 Addition:

Israel is one of the most vaccinated (and healthcare data sophisticated) nations on the planet. Much smaller than England and with less than 10 million residents, Israel and its residents have been early and effective at mitigating covid’s evolving threat. But even Israel is finding Delta a significant challenge. It is now in the seventh week of increased hospitalizations with no signs of softening case counts. The second chart below shows US, UK, and Israel covid hospitalizations on a comparative logarithmic scale. This helps to reveal potential patterns between such dramatically different population samples.