Elevation criteria

In North America, XBB.1.5 has reached a share of around 15% in samples collected at the beginning of January. Using a simple logistical model, it has a growth advantage of around 7-8%.

XBB.1.5 hence satisfies criteria 4 of the most recent Nextstrain clade naming criteria (https://next.nextstrain.org/blog/2022-04-29-SARS-CoV-2-clade-naming-2022):

A clade shows consistent >0.05 per day growth in frequency where it’s circulating and has reached >5% regional frequency

Furthermore, XBB.1.5 has additional Spike mutations S:G252V and S:S486P (known to increase ACE2 binding) and hence satisfies the additional criterion:

Additionally, for points 2, 3, and 4, we require the clade to show multiple mutations in S1 or particular mutations of known biological relevance.

XBB.1.5 as a proportion of all sequences in North America:

XBB.1.5 growth advantage vs all other sequences in North America:

Source: https://cov-spectrum.org/explore/North%20America/AllSamples/from=2022-07-25&to=2023-01-15/variants?nextcladePangoLineage=XBB.1.5*&dateSubmittedFrom=2020-01-06&dateSubmittedTo=2023-01-30&

Testing

Test build looks good, it's grey because input metadata does not have any 23A yet, this is expected:

https://next.nextstrain.org/staging/ncov/gisaid/trial/23A/global/all-time

Release checklist

If this pull request introduces new features, complete the following steps:

• Update docs/src/reference/change_log.md in this pull request to document these changes by the date they were added.