[...]

But while this is all encouraging, it is not clear that those same patterns observed abroad will hold here in the U.S. In fact, there are already early signs in hospitalization and ICU data that the experience of Omicron in America may be harsher than has been observed so far in Europe. This should perhaps not come as a surprise, given that Delta was much more lethal in the U.S. than in Europe — and the current data may still reflect some lingering cases of that variant. And it does not mean a tsunami of deaths is right around the corner or that this new variant will mean for the U.S. what Delta meant for India. (To begin with, the U.S. is, by global standards, very well vaccinated.) But the higher rate of severity observed so far is a reminder that the shape of a pandemic is not simply a matter of the biological properties of the virus; it is also determined by the social and immunological context in which that virus spreads. And it appears that, with Omicron as with Delta, the American context may be different enough to make a real difference, delivering perhaps considerably more severe illness and death than we’ve seen on the other side of the Atlantic.

With Delta, many Americans observed a miraculously light British wave and effectively ignored the real carnage that followed here — 100,000 Americans dead, and September and October was the deadliest two-month phase of the pandemic outside of last winter’s horrific surge. With Omicron, the same pattern — optimism from Europe followed by overlooked suffering here — seems troublingly possible again. And if you’re hoping for an outcome resembling South Africa’s, where COVID deaths during the Omicron wave didn’t reach even 10 percent of the previous peak, keep in mind that the U.S. began this wave on a Delta plateau 50 percent as high as our previous peak of daily deaths.

To this point in the Omicron surge, at least, American fatalities have not grown dramatically from that plateau, and the small rise we have observed is as likely to be the result of ongoing Delta cases as Omicron infections (that is how fast this surge has come upon us — our data are still telling a story about the last one). Anecdotal reporting from around the country suggests that while new patients are crowding hospitals and emergency rooms, to the doctors working in those hospitals the Omicron cases appear, on the whole, less serious. But while the New York Times reported this week this wave is putting less pressure on ICUs than previous ones, state data tell a different story: A comparable proportion of hospitalized cases are already now in the ICU as was the case in New York during the winter surge of early 2021. Then, hospital admissions reached 9,000; now, we’re already past 10,000. ICU admissions got to 1,600; now, we’re at 1,404.

[...]