National numbers, March 12

In the past week (March 2 through 8), the U.S. officially reported about 170,000 new COVID-19 cases, according to the CDC. This amounts to:

• An average of 24,000 new cases each day
• 52 total new cases for every 100,000 Americans
• 25% fewer new cases than last week (February 23-March 1)

In the past week, the U.S. also reported about 20,000 new COVID-19 patients admitted to hospitals. This amounts to:

• An average of 2,800 new admissions each day
• 6.1 total admissions for every 100,000 Americans
• 13% fewer new admissions than last week

Additionally, the U.S. reported:

• 1,900 new COVID-19 deaths (270 per day)
• 90% of new cases are caused by Omicron XBB.1.5; 2% by XBB.1.5.1; 1% by CH.1.1 (as of March 11)
• An average of 50,000 vaccinations per day

Following the same pattern we’ve seen for the last few weeks, COVID-19 spread is still on the decline nationally. Official case counts, hospital admissions, and wastewater surveillance data all continue to point in this direction.

This week, the decline in CDC-reported cases was sharper than it’s been in a couple of months (with 25% fewer cases reported than the prior week). But this may be due to reporting issues, rather than an actual change in transmission patterns: the CDC’s case trends page explains that Florida, Washington State, and Utah all did not report cases in the week ending March 8.

Still, I’m heartened by the fact that hospital admissions—which are reported more reliably—dropped by 13% this week, compared to smaller week-over-week changes over the last month. Wastewater surveillance data from Biobot also continue to show steady declines, though we’re still not close to the national lows observed during this time in 2021 and 2022.

Biobot’s data suggest declining surveillance in all four major regions of the country, with coronavirus levels in the Northeast now dropping below the Midwest, South, and West coast. Some individual counties in the Midwest are still reporting increased viral concentrations in their wastewater; I specifically noted Sheridan County and Teton County, Wyoming in Biobot’s data.

Omicron XBB.1.5 has been the dominant variant in the U.S. since mid-January, and we have yet to see a new subvariant rise to meaningfully compete with it. CH.1.1, which has driven increased transmission in other parts of the world, has remained under 2% of new cases nationally, per the CDC’s estimates.

The CDC’s latest variant update also breaks out XBB.1.5.1, an offshoot of XBB.1.5, at about 2% of new cases nationally. I have yet to see much discussion of this offshoot or how it differs from XBB.1.5; I’ll cover it more in future issues as we learn more. In addition, variant experts are keeping an eye on XBB.1.9, XBB.1.16, and other subvariants that have further mutated from the XBB lineage.

In his latest Substack newsletter, long-time COVID-19 commentator Eric Topol suggests that the U.S. might be in a welcome “break from COVID-19 waves.” He points to XBB.1.5’s dominance and the fact that its rise “was not associated with a surge of COVID-19 hospitalizations or deaths in the United States or elsewhere in the world” despite the subvariant’s increased capacity to spread.

At the same time, Topol explains the problem with our current “high baseline” of continued COVID-19 spread, which leads to continued severe cases among vulnerable people and the ongoing risk of Long COVID. He also explores the potential for another Omicron-like event, which would potentially cause another major surge. His article is helpful for understanding our current COVID-19 moment.

In NYC, where I live, COVID-19 case rates and test positivity are lower than they’ve been since early 2022—while still much higher than we saw last spring post-Omicron BA.1, or in spring 2021 as vaccines were widely rolled out. And the numbers are likely going to get more unreliable soon, as the city begins to wind down public testing sites.