A new SARS-CoV-2 variant, NB.1.8.1, is drawing heightened scrutiny from health authorities worldwide due to its rapid spread and potential to evade immune defences, even as it has yet to cause a significant spike in severe cases.
Detected through genomic surveillance in the United States, NB.1.8.1 has been identified among international travellers arriving at major airports, including those in California, Washington, Virginia, and the New York City area. The variant was flagged by Ginkgo Bioworks, a partner in the Centers for Disease Control and Prevention’s airport screening programme.
NB.1.8.1 is a sub-lineage of the Omicron JN.1 variant, which has been driving recent COVID-19 waves across Southeast Asia. In Singapore, NB.1.8 and LF.7, both JN.1 descendants, now account for over two-thirds of sequenced cases. The country reported a sharp rise in infections, with weekly cases increasing from 11,100 to 14,200 in early May.
Taiwan has also experienced a surge in cases linked to NB.1.8.1, with nearly 6,000 individuals seeking hospital care for COVID-19-related symptoms between April 27 and May 3. This marked a 78% increase from the previous week, according to the Taiwan Centers for Disease Control.
Australian researcher Mike Honey has highlighted NB.1.8.1’s significant growth advantage over other circulating variants. Genomic data indicates that NB.1.8.1 is growing at a rate of approximately 7% per day, suggesting it could outpace the currently dominant LP.8.1 strain in the coming weeks.
Laboratory studies have shown that NB.1.8.1 exhibits moderate resistance to neutralising antibodies, particularly those targeting Class 1 and Class 2 sites. This resistance is coupled with a strong affinity for the ACE2 receptor, enhancing its ability to infect human cells. Such characteristics raise concerns about the variant’s potential to spread widely, even among vaccinated populations.
In the United States, the Food and Drug Administration’s advisory panel has recommended updating COVID-19 vaccines to target newer strains related to the JN.1 variant. The panel’s discussions have been influenced by policy changes limiting vaccine access to individuals aged 65 and older or those at high risk, pending further research on broader eligibility.
India’s Strategic Airstrikes Prompted Pakistan’s Urgent Ceasefire Plea 