The World Health Association (WHO) issued a warning last week about a rise in COVID 19 infections worldwide, attributing the increase to the emergence and spread of the new NB.1.8.1 variant.

According to the WHO, the global positivity rate has reached The 11% positivity rate, a level not seen since July 2024. This increase is significant compared to the 2% positivity rate observed in 110 countries back in February 2025.

the WHO noted that the surge in cases is especially noticeable in the Eastern Mediterranean, Southeast Asia and Western Pacific regions.

Understanding the NB.1.8.1 Variant

The WHO has been monitoring changes in the global trends of variants of SARS-CoV-2 between January and May 2025, and has observed a notable increase in the prevalence of one particular variant.

“The circulation of LP.8.1 has been decreasing, and the reports of NB.1.8.1, a variant under monitoring (VUM), are increasing, reaching 10.7% of the global sequences notified in mid -May,” the WHO stated.

The first sample of NB.1.8.1 was collected on January 22, 2025, and it was designated as a variant under monitoring by the WHO on May 23, 2025. It is indeed now one of six viral variants being closely tracked by the organization.

Earlier in the year, the XEC variant was the most prevalent globally, followed by the KP.3.1.1. However, by February, LP.8.1 became the dominant variant,a trend that continued into mid-March. Since mid-April, the detection rate of Increase the detection of NB.1.8.1 has been on the rise, with cases reported in 22 countries to date.

“While the percentage remains low, it presents a significant increase compared to 2.5% registered four weeks before in the epidemiological week (SE) number 14 of 2025 (from March 31 to April 6),” the WHO added.

“The circulation of LP.8.1 has been decreasing, and the reports of NB.1.8.1… are increasing, reaching 10.7% of the global sequences notified in mid -May.”

Regional Prevalence of the NB.1.8.1 Variant

“Between the SE14 and the SE17 of 2025, a Increased circulation of NB.1.8.1 In the three WHO regions that systematically share SARS-COV-2 sequences,” the WHO reported.

Specifically, the increase was “8.9% to 11.7% for the Western pacific Region, from 1.6% to 4.9% for the region of Americas and from 1.0% to 6.0% for European region.”

As of the report, there were only five sequences of NB.1.8.1 identified in the Southeast Asian region, and none in the African or Eastern Mediterranean regions.

Symptoms and Characteristics of NB.1.8.1

This variant (nb.1.8.1) has gained attention in the United States, with detections reported at several airports. Subhash Verma, a professor at the University of Nevada, told CBS News that the variant “is more transmissible,” but the symptoms are similar to those of previous strains.

Amy Edwards, from Case Western Reserve University, noted that the variant appears to adhere more efficiently to human cells, perhaps facilitating its spread.

however, Edwards also stated that “it does not seem to be more serious,” attributing increased hospitalizations in places like hong Kong to seasonal patterns.

Specialists indicate that NB.1.8.1 Causes symptoms such as cough, throat pain, fever and fatigue. However, the WHO has stated that “despite the simultaneous increase in cases and hospitalizations in some countries where the NB.1.8.1 variant is widely extended,current data They do not indicate that this variant causes a more serious disease than other variants in circulation.”

“At the moment, There is no evidence of increases in indicators such as income at ICU and hospitalization deaths related to COVID-19, not even in mortality for any cause,” the WHO added.

The WHO also reassured that “Vaccines against COVID-19 are currently approved to remain effective against this variant, both in symptomatic and serious cases.”