XBB.1.5 is the latest Omicron subvariant to spread rapidly through the U.S. It is, of course, more transmissible and more capable of evading immunity from past infections than other versions of Omicron that have gone before it, as this lineage continues mutating. Scientists are still learning about XBB.1.5; it emerged from the U.S. during the holiday season, which has posed surveillance challenges. But we know enough to say that this variant is bad news for an already overstretched healthcare system.
Last month, the CDC started publishing data from a surveillance program focused on international travelers coming into the U.S. I talked to bioinformatics experts involved with the program to learn more about how it works.
Sources and updates for the week of September 25 include new booster shot data, CDC funding for COVID-19 testing and genomic surveillance, Long COVID studies, and more.
America’s current COVID-19 surge is being driven by BA.2 and its sublineage BA.2.12.1. But there are other versions of Omicron out there to which we need to pay attention—namely, BA.4 and BA.5. Here’s a brief FAQ on these two subvariants, including why scientists are concerned about them and where they’re spreading in the U.S.
Europe’s new surge is likely due to European leaders’ decisions to end all COVID-19 safety measures in their countries, combined with the rise of Omicron sublineage BA.2. As BA.2 prevalence increases here in the U.S.—and our leaders also end safety measures—we seem poised to follow in Europe’s footsteps once again. But a BA.2 surge is likely to look different from the intense Omicron surge that we experienced in December and January, in part because of leftover immunity from that Omicron surge.
What has the U.S. learned from the last two years, and what lessons can we take forward for future COVID-19 surges and other infectious disease outbreaks? The Biden administration has released a new pandemic preparedness plan that addresses these questions.
This week, the CDC added wastewater tracking to its COVID-19 data dashboard. Wastewater has been an important COVID-tracking tool throughout the pandemic, but it gained more public interest in recent months as Omicron’s rapid spread showed the utility of this early warning system. While the CDC’s new wastewater tracker offers a decent picture of national COVID-19 trends, it’s basically useless for local data in the majority of states.
An offshoot strain of the Omicron variant has been making headlines this week as it spreads rapidly in some European and Asian countries. While the strain, called BA.2 by virologists, has not yet been identified in the U.S. in large numbers, it’s already spreading here, too: scientists have picked it up in wastewater samples in some parts of the country.
Omicron is now causing nearly 100% of new COVID-19 cases in the U.S. Major Omicron news items for this week include the potential peak of the U.S.’s surge and real-world data from the CDC on how well booster shots work against this variant.
