A new Covid variant NB.1.8.1 has been detected. Credits: Anna Shvets, Pexels
A new Covid-19 variant, NB.1.8.1, associated with a surge in some cases in China and Asia, has now been detected in the US and has been confirmed among international travelers arriving between late April and mid-May.
New Covid Variant NB.1.8.1 Found at US Airport
According to data from Ginkgo Bioworksa test partner of the US Centers for Disease Control and Prevention (CDC) cases of the NB.1.8.1 variant were identified in airport travelers.
- California
- Washington State
- Virginia
- New York City
Travelers infected with the new Covid variant came from parts of Asia and Europe, including Spain
Sequence records uploaded to the Global Initiative on Sharing All Influenza Data (GISAID) confirm that infected travelers have arrived from China, Taiwan, Japan, South Korea, Thailand, Vietnam, France, Spain, and a wide range of countries between May 22nd and May 12th.
Apart from airport screenings, NB.1.8.1 cases have also been reported by local health officials in Ohio, Rhode Island and Hawaii, with prior detections occurring in California and Washington from late March to early April.
NB.1.8.1 has become the dominant variant in China, contributing to the highest Covid-19 levels in Hong Kong for over a year. A Hong Kong official reported:
- “Substantial increase” in emergency room visits and hospitalizations
- We invite the public to wear masks in busy areas and public transport
Similarly, Taiwan has seen an increase in severe cases and deaths, urging civil servants to stockpile vaccines and antiviral treatments in anticipation of further spread.
Should I worry about the new Covid variant NB.1.8.1?
So far, the variant does not appear to cause more severe illness than the previous strain. However, preliminary studies from Chinese researchers suggest that NB.1.8.1 has a higher ability to bind to human cells, which could be more contagious.
It does not significantly avoid immunity. This means that vaccines and past infectious diseases may still provide protection.
The US is preparing for the next Covid vaccine update
The potential impact of NB.1.8.1 was discussed at the US Food and Drug Administration (FDA) Advisory Council on Thursday, May 22, 2025. Authorities discussed how to update Covid-19 vaccines for the fall/winter season.
The Pfizer and Modanya data showed that candidate vaccines targeting Lp.8.1, another descendant of JN.1, also provided protection against NB.1.8.1.
There was debate about whether to update the vaccine or stick to last season’s version, but the panel unanimously agreed to target JN.1 strains of future vaccine updates. This was reported by CBS News.
The CDC reports that the overall COVID-19 rate in the United States is currently low, with low cases and hospital visits nationwide.
“Five years from now, we’re seeing a very clear pattern,” Natalie Thornberg, head of CDC’s respiratory virus lab division, added that Covid-19 can follow a more seasonal pattern.
However, she warned that while the current trends only show small genetic changes in the virus, there is still a possibility of major changes.
Has Covid-19 leaked out of the lab?
As new variants like NB.1.8.1 emerge and spread worldwide, some experts and officials are also reexamining the origins of the Covid-19 virus. Earlier this year, the CIA suggested that Covid-19 may have leaked from the lab. This is a theory that continues to promote international debate. Even the White House has published an online page entitled “Lab Leak: The True Origins of Covid-19.”
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