#16,023
The very good news from the United States is that between the uptake of vaccines, and likely aided by the warmer weather, the number of daily new COVID cases (roughly 12,000) has dropped to the lowest level since March of 2020.
This excellent news, however, is tempered by the rise of the Delta variant in the UK, which now accounts for > 95% of their infections, and has more than quadrupled the UK's (7-day) average number of daily cases over the past month (May 19th 1,845 vs. 8,808 June 16th).
Until very recently, the Delta variant was barely detected in the United States, as the B.1.1.7 (Alpha) variant has dominated for months. Late Monday, however, the CDC Elevated Delta (B.1.617.2) Variant to VOC (Variant of Concern) status, as signs of its spread continue to come in.
In Tuesday morning's blog, I noted that the last CDC update (as of 5/22/21) showed only 2.5% of US cases were due to the Delta variant, but that forward looking projections suggest that its share would more than double by the next update.
Furthermore, B.1.617.2 appeared on track to challenge B.1.1.7 for dominance in the U.S. later this summer.
While that next surveillance update isn't expected until early next week, yesterday the CDC updated its `Nowcast' projections (as of June 5th) - not to have doubled - but to have risen nearly 4-fold.
Although the P.1 variant (Gamma) remains in second place, it is rising at a slower rate than Delta, and should be well eclipsed by it before the end of June. Meanwhile Alpha's share has dropped again, making room for Delta's potential summer run up.
Barring something unexpected, Delta should become the dominant variant in the United States before end of the summer.
While current vaccines are believed to be reasonably effective against the Delta variant (albeit perhaps not as robust as against Alpha), vaccine uptake in the United States has slowed, with more than half the nation still not fully vaccinated.
A month ago, the UK appeared on track to drop all lockdown restriction on Monday, June 21st (`Lockdown Exit Day'). Earlier this week, the UK cancelled those plans for at least another month, due to the sharp increase in cased due to the Delta variant.
While we can (rightfully) celebrate the recent and dramatic decline in daily cases here in the United States, the rise of the Delta variant threatens to spoil that success. For now, our best defense lies in significantly increasing the uptake in COVID vaccines.
Failing that, we risk creating conditions conducive to another pandemic surge later this summer or fall.
