New COVID Variant NB.1.8.1 Spreading Globally, Says WHO

The World Health Organization (WHO) has raised an alert over the global spread of a new COVID-19 variant, NB.1.8.1, which it has now classified as a “variant under monitoring.”

According to the WHO, NB.1.8.1 is rapidly increasing in prevalence across parts of the world, with significant surges reported in the Eastern Mediterranean, Southeast Asia, and the Western Pacific regions. The variant, a sub-lineage of Omicron JN.1, was first identified in late January and has shown signs of greater transmissibility and immune escape.

Data from the WHO reveals that NB.1.8.1 accounted for 10.7% of global sequenced COVID-19 cases between April 21 and April 27, a sharp rise from 2.5% just a month earlier.

Though the variant spreads quickly, current evidence does not suggest it causes more severe illness compared to earlier strains. Nevertheless, its capacity to partially evade immunity from prior infections or vaccinations remains a concern.

In its most recent update on May 28, the WHO reported that the variant is contributing to rising case numbers in several countries, notably Cambodia, China, Hong Kong, and Singapore. It also noted that while LP.8.1 remains the dominant strain globally, NB.1.8.1 is gaining ground and warrants close observation.

The U.S. Centers for Disease Control and Prevention (CDC) has confirmed the presence of NB.1.8.1 in several states, including California, Virginia, Washington, and New York, largely among international travellers.

In China, where the variant now constitutes a majority of new cases, reports have surfaced about a distinctive symptom — a sharply painful sore throat. However, the Chinese CDC has not released data on hospitalisation or mortality rates. The country’s pandemic reporting has previously come under scrutiny for lack of transparency.

Australia’s genomic surveillance indicates that NB.1.8.1 now represents over 40% of COVID-19 cases in Victoria and is the dominant strain in wastewater samples collected in Perth. Similarly, South Korea has confirmed that its health authorities are closely tracking developments in neighbouring China and Hong Kong.

Medical experts say symptoms of NB.1.8.1 resemble previous Omicron sub-variants: sore throat, fatigue, mild cough, fever, muscle aches, and nasal congestion. Some patients may also experience gastrointestinal issues.

While the WHO has assured that neither LP.8.1 nor NB.1.8.1 currently pose an increased public health risk compared to other variants, it continues to monitor their evolution closely.