The US Centers for Disease Control and Prevention (CDC) has reported a surge in cases and hospitalizations caused by the NB.1.8.1 variant, which has grown from 15% to 37% since late May. This rise is attributed to its increased presence in Asia. However, the CDC notes that NB.1.8.1 appears only minimally more immune-evasive than the dominant LP.8.1 subvariant.
The World Health Organization (WHO) added NB.1.8.1 as a variant under monitoring (VUM) last month, citing concerns about rapid growth in proportion. Another emerging variant, XFG, has also seen an increase in proportion from 6% to 8% over the same period.
In contrast, the European Centre for Disease Prevention and Control (ECDC) reported slowly increasing COVID activity, but with no rise in severe disease indicators such as hospitalizations or ICU admissions. The head of respiratory viruses at ECDC, Eduardo Colzani, noted that NB.1.8.1 does not pose a greater threat than other Omicron descendants.
The CDC also warns that since SARS-CoV-2 activity was low over the winter, population immunity may have waned, especially among older adults and those with underlying health conditions. Despite this, COVID activity remains low in the US, with wastewater SARS-CoV-2 detections still at a low level, according to the latest CDC data.
Source: https://www.cidrap.umn.edu/covid-19/cdc-estimates-show-jump-nb181-covid-variant-proportions