COVID-19 Variant: US Connects to China Cases
- A new subvariant of the SARS-CoV-2 virus,designated NB.1.8.1, has been identified in international travelers arriving in the United States, according to the Centers for Disease Control and Prevention.
- The CDC reports that NB.1.8.1 has been detected in fewer than 20 genomic sequences within the national surveillance system.
- The emergence of NB.1.8.1, alongside other JN.1 family variants, has prompted public health agencies to strengthen genomic surveillance efforts.
NB.1.8.1 COVID Variant Detected in U.S. travelers; CDC Monitoring
Table of Contents
- NB.1.8.1 COVID Variant Detected in U.S. travelers; CDC Monitoring
- Limited U.S. Presence, Heightened Surveillance
- Public Health Response and Vaccine Considerations
- Geographic Distribution in the U.S.
- CDC Monitoring and Future Tracking
- NB.1.8.1: An Omicron Descendant
- Hong Kong’s Response
- Current COVID-19 Trends in the U.S.
- Wastewater Surveillance Data
- LP.8.1 Dominant in the U.S.
- FDA Considers Vaccine Updates
- WHO Assessment of LP.8.1
- WHO’s Stance on NB.1.8.1
- Future Vaccine Reformulation
- NB.1.8.1 COVID Variant: Your Questions Answered
A new subvariant of the SARS-CoV-2 virus,designated NB.1.8.1, has been identified in international travelers arriving in the United States, according to the Centers for Disease Control and Prevention. While the number of confirmed cases remains low, the emergence of this variant coincides with a surge in COVID-19 infections across several regions of Asia, particularly in mainland China and Hong kong.
Limited U.S. Presence, Heightened Surveillance
The CDC reports that NB.1.8.1 has been detected in fewer than 20 genomic sequences within the national surveillance system. As a result, it has not yet been included in the COVID Data Tracker, the agencyS primary tool for monitoring variant circulation within the U.S. The variant was detected through the federal Airport Monitoring Program, a collaborative effort with the biotechnology firm Ginkgo Bioworks.
Public Health Response and Vaccine Considerations
The emergence of NB.1.8.1, alongside other JN.1 family variants, has prompted public health agencies to strengthen genomic surveillance efforts. While current data suggests that this variant does not cause more severe illness, its circulation has led to renewed precautionary measures in East Asian countries.Adjustments to vaccination strategies for the 2025-2026 season are also under evaluation.
Geographic Distribution in the U.S.
According to The Economic Times, NB.1.8.1 has been identified at airports in California, Washington, Virginia, and the New York metropolitan area, based on data from the CDC’s airport monitoring program. These detections are part of ongoing efforts to track new variants entering the country via international travelers.
CDC Monitoring and Future Tracking
The CDC stated that while NB.1.8.1 has not yet reached the prevalence threshold required for inclusion in the COVID Data Tracker, its evolution is being closely monitored. A CDC spokesperson told Fox News that the variant will be added to the surveillance panel if its proportion of cases increases.
NB.1.8.1: An Omicron Descendant
NB.1.8.1 is a sub-lineage of the JN.1 variant, which itself is a descendant of the Omicron strain that has been dominant since late 2021. The Indian Medical research council (ICMR) reports that this sub-lineage has also been detected in India, along with another subvariant called LF.7, in regions experiencing localized increases in cases. india’s Ministry of health and Family Welfare has urged state governments to enhance sample sequencing to monitor the spread of these emerging lineages.
Hong Kong’s Response
In Hong Kong, the Department of Health has recommended that high-risk individuals wear surgical masks in enclosed public spaces. Though,the department also stated that there is no evidence to suggest that NB.1.8.1 causes more severe COVID-19 than other variants within the same family.
Current COVID-19 Trends in the U.S.
In its weekly update on May 23,2025,the CDC reported that emergency room visits for COVID-19,seasonal influenza,and respiratory syncytial virus (RSV) remain low across the United States. the agency’s statistical models project that this trend will continue for the next two weeks.
Wastewater Surveillance Data
data from the National Wastewater Surveillance System indicate that most states have low or very low levels of viral circulation. An exception is South Dakota, where higher viral loads have been observed in collected samples.
LP.8.1 Dominant in the U.S.
According to a CDC surveillance report cited by Reuters, the predominant variant in the United States as of May 10, 2025, is LP.8.1, also a descendant of JN.1. This subvariant accounts for approximately 70% of sequenced samples nationwide during that period.
FDA Considers Vaccine Updates
The Food and Drug Administration (FDA) has convened its self-reliant advisory committee to evaluate the composition of COVID-19 vaccines for the 2025-2026 season. Reuters reports that the FDA will require manufacturers to conduct new clinical trials to gain approval for updated booster vaccines for individuals under 65 without high-risk conditions.
WHO Assessment of LP.8.1
The World health Organization (WHO) has classified the additional risk to public health associated with the LP.8.1 variant as low. In its technical bulletin of May 22, 2025, the agency stated that existing vaccines remain effective in reducing symptomatic and severe disease caused by this sub-lineage.
WHO’s Stance on NB.1.8.1
While NB.1.8.1 has not yet been individually assessed by the WHO, its relationship to other JN.1 variants suggests similar clinical behavior. The WHO continues to emphasize genomic surveillance as a crucial tool for anticipating changes in the virus’s epidemiology.
Future Vaccine Reformulation
The FDA is evaluating the potential reformulation of booster vaccines to better address the dominant sub-lineages of JN.1, such as LP.8.1. According to Reuters, regulators believe that the XBB.1.5 lineage, used in previous boosters, no longer reflects the majority of circulating variants. A new vaccination strategy could be ready before the fall of 2025, pending clinical trial results and regulatory approval.
NB.1.8.1 COVID Variant: Your Questions Answered
the emergence of new COVID-19 variants continues to be a key focus for public health officials. This Q&A provides the latest details on the NB.1.8.1 subvariant, its presence in the U.S., and the public health response.
NB.1.8.1 is a new subvariant of the SARS-CoV-2 virus. It’s a sub-lineage of JN.1,which itself descends from the Omicron strain that has been dominant as late 2021. This lineage has been identified in international travelers arriving in the United States,signaling the ongoing evolution of the virus.
According to the Centers for Disease Control and prevention (CDC), NB.1.8.1 has been identified at airports in several U.S. locations, including California, Washington, Virginia, and the New York metropolitan area. These detections are part of ongoing efforts to monitor new variants entering the country via international travelers.
Currently, the presence of NB.1.8.1 in the U.S. is limited. The CDC reports that the variant has been detected in fewer than 20 genomic sequences within the national surveillance system.As an inevitable result, it hasn’t yet reached the prevalence threshold required for inclusion in the COVID Data Tracker. However, its evolution is being closely monitored, and it will be added to the surveillance panel if its proportion of cases increases.
While the number of confirmed cases of NB.1.8.1 remains low, its emergence coincides with a surge in COVID-19 infections in several regions, notably in Asia. Current data suggest that NB.1.8.1 does not cause more severe illness than other variants within the same family, according to the department of Health in Hong Kong. However, public health agencies are strengthening genomic surveillance efforts.
The CDC is closely monitoring the evolution of NB.1.8.1. the variant was detected through the federal Airport Monitoring Program, a collaborative effort. The agency is tracking new variants entering the country via international travelers and will add NB.1.8.1 to the surveillance panel if the number of cases increases.
In Hong Kong, the Department of Health has recommended that high-risk individuals wear surgical masks in enclosed public spaces. Public health agencies are strengthening their genomic surveillance efforts.
The FDA is evaluating the potential reformulation of booster vaccines to better address dominant JN.1 sub-lineages, such as LP.8.1. According to Reuters, regulators believe that the XBB.1.5 lineage, used in previous boosters, no longer reflects the majority of circulating variants. A new vaccination strategy could be ready before the fall of 2025, pending clinical trial results and regulatory approval.
While NB.1.8.1 has not yet been individually assessed by the WHO, its relationship to other JN.1 variants suggests similar clinical behavior. The WHO continues to emphasize genomic surveillance as a crucial tool for anticipating changes in the virus’s epidemiology.
According to a CDC surveillance report cited by Reuters, the predominant variant in the United States as of May 10, 2025, was LP.8.1, also a descendant of JN.1. LP.8.1 accounted for approximately 70% of sequenced samples nationwide during that period. The WHO classified the additional risk associated with LP.8.1 as low.
As of May 23, 2025, the CDC reported that emergency room visits for COVID-19, seasonal influenza, and respiratory syncytial virus (RSV) remain low across the United States. The agency’s statistical models project that this trend will continue for the next two weeks. wastewater surveillance data also indicate that most states have low or very low levels of viral circulation, with the exception of South Dakota.
Continue monitoring updates from the CDC (https://www.cdc.gov/) and the WHO (https://www.who.int/) for the latest information on COVID-19 variants and public health recommendations.