Medical Case Reports

In summer 2025, the Nimbus (NB.1.8.1) and Stratus (XFG) variants were competing for dominance (see previous post  Nimbus and Stratus: Cloudy With a Chance of Covid ). By that point, earlier JN.1-descended variants such as LP.8.1 had already been largely displaced. That competition is now largely settled, with Stratus and its descendants firmly in the lead across most regions. As of early January 2026, Stratus (XFG) and its descendants dominate globally. In the U.S., sequencing and wastewater data show XFG making up 60–70% of cases, and when its sublineages (XFG.14.1, XFG.1, XFG.6) are included, the total reaches ~80% by late December. Nimbus has fallen sharply and now accounts for roughly 5% of sequenced cases. The new variant to watch is BA.3.2 nicknamed “Cicada”. Unlike recent variants that evolved incrementally from JN.1, BA.3.2 represents a larger evolutionary jump. It's a descendant of early Omicron BA.3, a lineage that largely disappeared in 2022. Cicada was designated by WHO...

As we venture into the end of summer, there’s no denying that COVID-19 is making its move again. Covid waves always follow a seasonal pattern  - two waves per year: winter and summer or fall. So far, the smallest (not in terms of deadliness though, just the number of infected) wave hit during the winter of 2020-2021, while the Omicron surge of 2021-2022 took the crown for the biggest wave. Last year was a bit of a wild card, with the summer/fall wave being slightly taller than the winter one. However, so far, this year hasn’t had much of a summer/fall wave (yet) but hold on tight because things are looking a little more intense as we approach the winter. From December 2024 to February 2025, we experienced what could be called "Wave X," a quieter episode compared to earlier waves, but it still made its presence felt. Fast forward to August 2025, and we’re beginning to see the rise of the next wave—a little like what we saw in 2023 and 2024. According to Mike Hoerger’s post on ...