WHO weighs in on Omicron XBB.1.5 subvariant; US extends COVID health emergency – Lisa Schnirring – January 11, 2023
More than 82% of XBB.1.5 sequences are from US
The WHO said 5,288 XBB.1.5 sequences have been reported between Oct 22 and Jan 11 from 38 countries. Just over 82% are from the United States, with the United Kingdom (8.1%) and Denmark (2.2%) among other countries reporting the most sequences.
The subvariant’s genetic characteristics and growth rate estimates suggest it may contribute to rising cases. However, the WHO said its confidence in the assessment is low, given that the growth advantage estimate is just from the United States. Last week, US officials fine-tuned their assessment of XBB.1.5 proportions, showing less vigorous growth than previously thought, though spreading is still robust.
Along with BQ.1 subvariants, XBB.1.5 is one of the most immune evasive variants to date, the WHO said. So far, there is no evidence that illnesses involving the subvariant are more severe, and XBB.1.5 doesn’t carry mutations that are known to increase severity.
At a WHO briefing today, Director-General Tedros Adhanom Ghebreyesus, PhD, urged countries that experience intense transmission to increase sequencing and to share the sequencing. He said since the peak of the Omicron wave, the number of shared sequences has dropped 90% and the number of countries sharing sequences has fallen by one third.
In an update yesterday, the sequence sharing database GISAID said China continues to ramp up its genomic surveillance, with a host of genome sequences shared by provinces, cities, universities, and private labs. So far, the data suggest that the sequences from China resemble known circulating variants. New data from Shanghai show a range of known lineages from multiple separate introductions. GISAID also marked the third anniversary of its EpiCoV database, which now has 14.5 million sequences shared by 215 countries and territories.