WHO: XBB.1.16 variantin riskiarviosta 17.4. 2023

 

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XBB.1.16 Initial Risk Assessment, 17 April 2023
XBB.1.16 is a descendent lineage of XBB, a recombinant of two BA.2 descendent lineages. XBB.1.16 was firstreported on 09 January 2023, and designated a variant under monitoring (VUM) on 22 March 2023. On 17 April 2023,

 
XBB.1.16 was designated a variant of interest (VOI).  

XBB.1.16 has a similar genetic profile as the VOI XBB.1.5, with the additional E180V and K478R amino acid mutations in the spike protein compared to their parent XBB.1.

 
As of 17 April 2023, 3648 sequences of the Omicron XBB.1.16 variant have been reported from 33 countries (GISAID,
XBB.1.16 searched using variant defining nucleotide mutations T12730A, T28297C, A28447G). The majority of theXBB.1.16 sequences are from India (63.4%, 2314 sequences). The other countries with at least 50 sequences include
the United States of America (10.9%, 396 sequences), Singapore (6.9%, 250 sequences), Australia (3.9%, 143 sequences), Canada (2.6%, 94 sequences), Brunei (2.4%, 89 sequences), Japan (2.0%, 73 sequences) and the United Kingdom (2.1%, 75 sequences).

 
Globally, there has been a weekly rise in the prevalence of XBB.1.16.  

During epidemiological week 13 (27 March to 2 April 2023), the global prevalence of XBB.1.16 was 4.15%, an increase from 4 weeks prior (epidemiological week9, 27 February to 5 March 2023), when the global prevalence was 0.52%.
Following a sustained increase in the prevalence of XBB.1.16 and sustained growth advantage reported from several countries, and following the advice of the WHO Technical Advisory Group on SARS-CoV-2 Viral Evolution (TAG-VE) on a meeting convened on 17 April 2023, XBB.1.16 has been designated as a VOI.

 
The global risk assessment for XBB.1.16 is low as compared to XBB.1.5 and the other currently circulating variants, at this current time and with available evidence (see risk assessment table below). 

 While growth advantage and immune escape properties are observed in different countries and immune backgrounds, including in countries where XBB.1.5 has become the dominant variant recently, no changes in severity have been reported in countries where XBB.1.16 are reported to be circulating. 

 

 In India and Indonesia, there has been a slight increase in bed occupancy
numbers. However, the levels are much lower than seen in previous variant waves.

 
Taken together, available information does not suggest that XBB.1.16 has additional public health risk relative to XBB.1.5 and the other currently circulating Omicron descendent lineages.

 

 However, XBB.1.16 may become dominant
in some countries and cause a rise in case incidence due to its growth advantage and immune escape characteristics.

 
WHO and its Technical Advisory Group on SARS-CoV-2 Evolution (TAG-VE) continue to recommend Member States prioritize the following studies to better address uncertainties relating to antibody escape, and severity of XBB.1.16.
The suggested timelines are estimates and will vary from one country to another based on national capacities:
• Share information on growth advantage for XBB.1.16 in your country and/or share sequence
information (1-4 weeks)
• Neutralization assays using human sera, representative of the affected community(ies), and live XBB.1.16 virus isolates (2-4 weeks, see below table for results of studies that were performed so far)
• Comparative assessment to detect changes in rolling or ad hoc indicators of severity (4-12 weeks, see below table for results of studies that were performed)
 

The WHO Technical Advisory Group on COVID-19 Vaccine Composition (TAG-CO-VAC) continues to regularly assess the impact of variants on the performance of COVID-19 vaccines to inform decisions on updates to vaccine composition.(1)

 

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The risk assessment below ( kts. linkki)  is based on currently available evidence and will be revised regularly as more evidence and data from additional countries become available

https://www.who.int/docs/default-source/coronaviruse/21042023xbb.1.16ra-v2.pdf?sfvrsn=84577350_1