winter is coming. second. Over the past two years, cooler temperatures have caused Seasonal COVID increases, which turned into huge waves when new variables appeared at the wrong time. In Western Europe, it seems the first part of that story is definitely starting to appear again. Cases and hospitalizations began to rise last month. No new variant has become dominant just yet, but experts are keeping an eye on a pair of potentially troublesome viral offshoots called BQ.1 and XBB. “We have the seasonal spike really moving,” says Emma Hodcroft, a molecular epidemiologist at the University of Bern, Switzerland. If one of these new variants comes on top of that, Europe could end up with another double whammy.
The United States may not be far behind. America’s COVID numbers decline when aggregated across the country, but that’s not true in every region. That decline is largely driven by trends in California, says Samuel Scarpino, vice president of pathogen surveillance at the Rockefeller Foundation’s Epidemic Prevention Initiative. In colder New England, hospitalization numbers are already up by nearly 30 percent, and more viruses are emerging in Sewagevery.
There are several reasons to be more optimistic about this winter than it was last. The United States is just emerging from a long and high region Covid plateauWhich means that there is a lot of immunity in the population that can limit the spread of the virus. appreciate 80% of Americans They had an Omicron last year. The BQ.1 and XBB are Not It surpassed previous versions as quickly as Omicron did last winter. It seems unlikely that they will cause a winter crush of hospitals like the original Omicron wave, although the full picture of its severity and potential for reinfection is still emerging. (Both of these variants are descended from Omicron: BQ.1 comes from BA.5, and XBB comes from two different BA.2 strains recombined into one. Confused by all these letters and numbers? Here’s A guide to understanding genealogical names.)
Laboratory data tell us that both subvariants are capable of significant immune evasion. XBB is already driving a boom in Singapore. BQ.1, and its closely related descendant BQ.1.1, are on the rise in Western European countries and now account for about 8 to 10 percent of cases, according to Hodcroft — but they are probably not widespread enough to explain why COVID rates are already soaring above. Many countries in the region may already have peaked at the moment, but with the spread of BQ.1 and BQ.1.1, they could launch another wave.
The changing situation this winter may look different than in the past. In contrast to previous winters, when Alpha and Omicron took clear paths to control, now “there is a soup of variables,” says Tom Peacock, a virologist at Imperial College London. One of these diseases may monopolize infection in certain parts of the world, and another in another. Peacock says that BQ.1 and XBB are distinct enough from each other that they could end up trading together, or not. It is too early to say for sure. He adds that we could also get another unwelcome surprise — just as Omicron turned our winter predictions upside down last Thanksgiving.
With a few more weeks of data, the real-world risk and re-infection of BQ.1 and XBB will be more clear. However, our window into the reality of COVID is more blurry than ever. As governments step up to curb the spread of the coronavirus, they have also tightened surveillance. “The data that goes into these models is much weaker because we don’t sequence as much,” Peacock says. in the United States , data We have a suggestion that BQ.1 and BQ.1.1 account for about 10 percent of cases. Case numbers are also less reliable due to an increase in at-home testing, which is generally not officially reported.
Comparing regions is also becoming more difficult. Back in March 2020, every country started with roughly the same amount of immunity to COVID: none. Since then, we’ve all been immune to each other. South Africa, for example, has a large beta wave that hasn’t hit Europe. Europe saw a big and distinct BA.2 wave Not achieved in the United States Now countries administer a mixture of BA.1 and BA.5 divalent enhancers, depending on availability, and provide enhancers to different segments of their population. As we are already seeing in the United States, different parts of the same country will likely experience the COVID winter differently. “What’s happening in Boston is not what’s happening in Los Angeles,” says Scarpino. For communities to respond to the situation on the ground, “we need to have more local, relevant information in real time.”
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