The Centers for Disease Control and Prevention’s (CDC) airport screening program has detected multiple cases of the new COVID-19 variant NB.1.8.1, which has been linked to a significant surge of the virus in China.
Cases linked to the NB.1.8.1 variant have been reported in arriving international travelers at airports in California, Washington state, Virginia, and the New York City area, according to records uploaded by the CDC’s airport testing partner, Ginkgo Bioworks.
Details about the sequencing results, which were published in recent weeks on the GISAID (Global Initiative on Sharing All Influenza Data) virus database, show that the cases stem from travelers from numerous countries, including Japan, South Korea, France, Thailand, the Netherlands, Spain, Vietnam, China, and Taiwan. The records indicate that the travelers were tested between April 22 and May 12.
A CDC spokesperson did not immediately respond to a request for comment from CBS News.
Cases of NB.1.8.1 have also now been reported by health authorities in other states, including Ohio, Rhode Island, and Hawaii, separately from the airport cases. In California and Washington state, the earliest cases date back to late March and early April.
Experts have been closely monitoring the variant, which is currently dominant in China and is on the rise in parts of Asia. Authorities in Hong Kong report that COVID-19 rates in the city have climbed to their worst levels in at least a year, following a “significant increase” in reported emergency room visits and hospitalizations driven by COVID-19.
While authorities in Hong Kong state that there is no evidence suggesting the variant, a descendant of the XDV lineage of the virus, is more severe, they have begun urging residents to wear masks in public transportation or crowded places as cases have increased.
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.
Preliminary data from researchers in China suggest that the NB.1.8.1 variant is not more effective at evading the immune system compared to other emerging strains. However, it does exhibit a greater ability to bind to human cells, indicating a potential for increased transmissibility.
“A More Predictable Pattern”
The strain was discussed multiple times during a Thursday meeting of the Food and Drug Administration’s (FDA) outside vaccine advisors as they deliberated whether and how to recommend updating COVID-19 vaccines for the upcoming fall and winter seasons.
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 that switching to a different JN.1 descendant, LP.8.1, which has been dominant in recent months, could also enhance protection against NB.1.8.1.
“The LP.8.1 vaccine has the highest titers against LP.8.1, which is dominant in the U.S. and many other regions, and cross-neutralizes other currently circulating variants, including NB.1.8.1, a dominant JN.1 subvariant in many Asian countries,” Darin Edwards, lead of Moderna’s COVID-19 program, informed the panel.
The committee unanimously supported recommending that the coming season’s vaccines should target some form of the JN.1 variant but was divided on the specifics. Some members favored allowing vaccine manufacturers to continue using last season’s vaccines, while others advocated for the update to target the LP.8.1 descendant of JN.1 that Pfizer and Moderna have already prototyped.
“Although one can’t predict evolution, and you don’t know how this is going to keep diversifying, the overwhelming odds are that what does come and predominate in the next few months, the next six months, next year will come from something that’s circulating now. It won’t come from something that doesn’t exist any longer,” stated Jerry Weir, director of the FDA’s division of viral products.
Currently, CDC and FDA officials informed the panel that only one strain — a variant called XFC — has been significantly growing in the U.S. However, they cautioned that the virus’s evolution has been unpredictable, even as the country has settled into a relatively predictable pattern of two surges annually: one in the summer and one during the winter.
The past season only witnessed an evolutionary “drift” in the virus, as opposed to the significant replacements driven by highly mutated strains in some earlier years. While COVID-19 trends increased over the winter, they remained considerably below previous peaks.
“Throughout this winter, we didn’t see that strain replacement that we have in the past couple of years. But I’m not saying that the virus will not shift again in the immediate future,” Natalie Thornburg of the CDC told the panel. Thornburg is the acting chief of the laboratory branch in the CDC’s division for coronaviruses and other respiratory viruses.
Rates of COVID-19 have now declined to low levels nationwide, as measured through emergency room visits and wastewater testing.
“I do think after five years now, we are seeing very distinct patterns that are falling into a more predictable pattern,” Thornburg concluded, referencing a “seasonality analysis” that the agency has been working on regarding the virus.
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