N.B.1.8.1 is growing fast in South East Asia and the Western Pacific where it is now the dominant variant. 

Estimated percent of the N.B.1.8.1 Covid variant detected in Covid samples for selected countries. Jan 6 to May 19, 2025

The methods used to measure the percent of variants differs between countries and consequently are not directly comparable. In addition, there is high degree of uncertainty in this data due to the low number of samples sequenced.
Chart: Bob Hawkins Source: COVSpectrum (GISAID Data) Get the data Created with Datawrapper