Overview

• The World Health Organisation has designated NB.1.8.1 as a ‘variant under monitoring’ after it accounted for over 10 percent of global sequences and became dominant in China and Hong Kong.
• The Centers for Disease Control and Prevention detected NB.1.8.1 through airport surveillance in California, Virginia, New York and Washington state and reported fresh cases in Ohio, Rhode Island and Hawaii.
• Genetic analyses highlight spike protein mutations A435S, V445H and T478I that may enhance cell entry and partly evade immunity from prior infection or vaccination.
• Hospital admissions have risen sharply in regions where NB.1.8.1 is prevalent, although reported illness severity remains comparable to other Omicron subvariants.
• WHO advises against travel or trade restrictions and urges countries to continue vaccination campaigns and strengthen respiratory disease preparedness.