As the international community is closely monitoring, the global spread of Omicron Variant NB.1.8.1, China announcement May 23rd, it was a major variant spreading throughout the country.
On the same day, the World Health Organization’s advisory group classified NB.1.8.1 as a surveillance variant as the detection of surveillance efforts around the world is increasing.
The WHO said it considers the NB.1.8.1 variant, first detected in January this year, to a low risk of public health “at a global level.” Currently, it is not considered a variant of interest or concern. This variant is a descendant of Jn.1 and is a sublimation of Omicron.
As of May 18, 518 sequences of new variants have been submitted to GISAID by 22 countries. This accounts for 10.7% of global sequences for Epidemiology Week 17 (April 21-27, 2025). This represents a significant increase in variant detection from 2.5% in week 14 (March 31 to April 6, 2025).
The domination of NB.1.8.1 is particularly prominent in Asia. This is just close to China.
China has revealed a sharp increase in reported covid cases driven primarily by the NB.1.8.1 variant, with residents reporting symptoms such as severe burn pain, cough and fever.
The latest monthly update from the China Centers for Disease Control and Prevention (China CDC) reported that the average Covid-19 positivity rate for outpatient and emergency flu-like cases in April increased from 7.5% to 16.2%, while the positivity rate for hospitalized cases increased from 3.3% to 6.3%.
The data showed an increasing but fluctuating trend, focusing on 168,507 confirmed cases nationwide, including 340 “severe cases” and nine deaths caused by Covid-19 infections and patients with basal conditions. The Omicron subbranch NB.1.8.1 dominated gene sequencing outcomes.
It is difficult to assess the true magnitude of the current outbreak, due to past records of Chinese authorities concealing past infections and information.
Covid-19 cases are rapidly increasing in many countries
Covid-19 infections have been changing to be dominated by the NB.1.8.1 variant in recent weeks, and are rising sharply in Taiwan.
The Taiwan Centers for Disease Control and Control (Taiwan CDC) reported that between May 11 and May 17 (Epidemiological Week 20), there were 19,097 outpatient and emergency room visits for Covid-19, showing an 88% increase from the previous week. However, we noted that this was lower than the 23,778 visits recorded in the 20th week of 2024.
From May 12 to May 19, Taiwan recorded 93 severe and severe Covid-19 incidents and four deaths, with the highest outpatient visits and severe outcomes this year.
Taiwan CDC spokesman Lo Yi-Chun said the NB.1.8.1 variant spreads more easily, as it is better to avoid body immune defenses like antibodies such as vaccines and past infections.
Chinese scientists said the same in a report published on the properties of NB.1.8.1 on May 1, noting its high infectivity and immunity avoidance. Researchers suggested that Nb.1.8.1 could control future waves.
Thailand is working on a parallel increase in Covid-19, reporting 33,030 new cases in week 20, double the number of cases from around 16,000 the previous week, the Bangkok Post reported.
Unlike Taiwan, Thai surges are driven by another variant, and NB.1.8.1 is not yet dominant.
The US airport has also detected several NB.1.8.1 cases, with health officials in Ohio, Rhode Island, Hawaii, California and Washington confirming the infection.
Recent data from GISAID show NB.1.8.1 cases of travelers from Japan, Korea, France, France, Thailand, Netherlands, Spain, Vietnam, China and Taiwan to the US from Japan, Korea, France, Thailand, Vietnam and China tested between April 22nd and May 12th.
Europe also reported NB.1.8.1 cases in April 2025, particularly in France, Germany, Spain, Greece and Ireland.
As of May 26, 2025, the WHO dashboard shows France with a 19% positive Covid-19 test rate outside of Asia.
Mexico’s positivity rate is 15%, Burkina Faso in West Africa is 12%, Ethiopia is 10%, and both Saudi Arabia and Kazakhstan are 7.5%.
India also reports that it is a descendant of JN.1, seeing an increase in the NB.1.8.1 variant and LF.7. The Covid-19 vaccine rolled out since June 2024 is based on the JN.1 variant.
In an update to monitoring, the WHO said, “Despite the concurrent increase in cases and hospitalizations in some countries where NB.1.8.1 is widespread, current data do not show that this variant leads to more serious illness than other variants in circulation.”
Experts encourage people to feel sick, rest, stay hydrated, self-revitalize and use antiviral agents when needed. People with comorbidities are advised to maintain personal hygiene and precautions to reduce the risk of infection.
From NTD News
