The spread of a new Covid variant – NB.1.8.1 – has been tracked in states across America after a large surge in China, although right now, say experts, LP.8.1, which is a descendant of JN.1, is the nation’s dominant strain.
The US Centres for Disease Control said it was in regular contact with international partners, and aware of reported NB.1.8.1 cases in China, an agency spokesperson told The Independent. It said there had been too few US sequences reported thus far for the variant to be included in its dashboard.
In Asia, however, it has resulted in increased hospital admissions and emergency room visits.
Hong Kong authorities said that infection rates in the city had climbed to the worst levels they have seen in at least a year. They added that while there is no evidence that the variant is more severe, they have begun urging residents to mask when in public transportation or crowded places as cases have climbed.
Health authorities in Taiwan have also reported a rise in emergency room visits, severe cases and deaths. Local health authorities say they are stockpiling vaccines and antiviral treatments in response to the epidemic wave.
The World Health Organisation has designated the strain as a SARS-CoV-2 variant under monitoring, with increasing proportions globally. There are currently six being tracked by the agency.
It has spread throughout 22 countries. In the US, it has been traced to New York, California, Arizona, Ohio and Rhode Island, according to records from local health officials at the CDC’s airport testing partner Ginkgo Bioworks.
Details about the sequencing results, which were published in recent weeks on the GISAID, or Global Initiative on Sharing All Influenza Data, virus database, show the cases stem from travellers from a number of countries, including Japan, South Korea, France, Thailand, the Netherlands, Spain, Vietnam, China and Taiwan.
The travellers were tested between 12 April and 12 May, the records show.
Related infections
The public health risk posed by this variant is evaluated as low at the global level, the WHO said.
“Despite a concurrent increase in cases and hospitalisations in some countries where NB.1.8.1 is widespread, current data do not indicate that this variant leads to more severe illness than other variants in circulation.”
But while it may not be particularly severe, it may infect people more easily than previous variants, with scientists saying there is some evidence that the variant binds more tightly to human cells.
“Data indicate that NB.1.8.1 does not lead to more severe illness than previous variants, but it appears to have a growth advantage, suggesting it may spread more easily,” Subhash Verma, a Professor of microbiology and immunology at the University of Nevada, Reno School of Medicine, told CBS News this week.
“In other words, it is more transmissible.”
Currently-approved Covid shots are expected to remain effective against this variant and protect against severe disease, although access to the vaccines is being limited by the Trump administration.
‘More predictable pattern’
The new strain came up multiple times during a meeting last week of the FDA outside vaccine advisers, as they wrestled with whether and how to recommend updating the vaccines for the coming winter season.
Vaccines from last season targeted a descendant of the JN.1 variant called KP.2. Early data presented to the committee by Pfizer and Moderna suggested switching to a different JN.1 descendant that has been dominant in recent months, called LP.8.1, could boost protection against NB.1.8.1, too.
“The LP.8.1 vaccine has the highest titers against LP.8.1 … and cross-neutralises other currently circulating variants, including NB.1.8.1,” Darin Edwards, lead of Moderna’s Covid-19 programme, told the panel.
The committee unanimously backed recommending that the coming season’s vaccines should target some kind of JN.1 variant, but was split on the details. Some favoured allowing vaccine makers to stick with last season’s vaccines, while others called for the update to target the LP.8.1 descendant of JN.1 that Pfizer and Moderna have prototyped.
CDC and FDA officials cautioned that the evolution of the virus has been unpredictable, even as the country has settled into a relatively predictable pattern of two surges a year: once in the summer and once over the winter.
See more from MedicalBrief archives:
Covid cases rising in Asian countries
Increase in Covid-19 activity abroad