COVID XBB.1.5 risk is not ‘low’: Check WHO's latest assessment for Omicron variant
1 min read . Updated: 28 Jan 2023, 04:08 PM IST
PremiumThe number of cases associated with XBB.1.5 is still low and thus severity cannot yet be confidently assessed, WHO cited
World Health Organisation (WHO) has recently revised the risk assessment for Omicron XBB.1.5 variant from "Low" to "Moderate". WHO noted the variant is likely to contribute to increases in case incidence globally and also mentioned that ‘number of cases associated with XBB.1.5 is still low and thus severity cannot yet be confidently assessed.’
What is the Omicron XBB.1.5 variant?
XBB.1.5 is descendent lineage of XBB, which is a recombinant of two BA.2 descendent lineages. In the last 4 months, 8931 sequences of the Omicron XBB.1.5 variant have been reported from 54 countries including the United States of America (75.0%), the United Kingdom (9.9%), Canada (3.0%), Denmark (2.0%), Germany (1.5%), Ireland (1.3%) and Austria (1.3%).
WHO said, ‘XBB.1.5 is likely to contribute to increases in case incidence globally. There is moderate-strength evidence for increased risk of transmission and immune escape. From reports by several countries, no early signal of an increase in severity has been observed. The number of cases associated with XBB.1.5 is still low and thus severity cannot yet be confidently assessed.’
Here is the full analysis:
Growth advantage: In the United States of America, XBB1.5 is increasing in many regions (the prevalence of XBB.1.5 in some regions is predicted to be 80%, while in others, 20-50%). In the United Kingdom, the growth advantage relative to BQ.1.1 was estimated to 38.9%, with high uncertainty due to the small number of sequenced XBB.1.5 cases. Assessment: Moderate
Antibody escape: XBB.1.5 is shown to be as Moderate immune evasive as XBB.1, one of the Omicron subvariants with the highest immune escape to date. Antibody titers against XBB.1 were mostly absent in individuals with a history of vaccination with the index vaccine (2-4 doses), were higher in those who recently received a bivalent (BA.5) vaccine booster, and highest in individuals with hybrid immunity. Assessment: Moderate
Severity: There are currently no data on real world vaccine effectiveness against severe disease or death. Severity assessments in human populations are ongoing. The number of Low cases associated with XBB.1.5 is still low and thus clinical severity cannot yet be confidently assessed.
