Nikhil Prasad Fact checked by:Thailand Medical News Team Jul 22, 2025 7 months, 3 days, 1 hour, 31 minutes ago
Medical News: New Wave of Subvariants Threatens Global Immunity
Scientists from Columbia University Vagelos College of Physicians and Surgeons and the University of Michigan have issued an urgent warning after identifying several newly emerging SARS-CoV-2 subvariants—specifically LP.8.1.1, NB.1.8.1, and XFG—that are rapidly outcompeting previous variants across North America, Europe, and Asia. These subvariants have evolved unique traits that either boost their ability to bind to human receptors or evade antibodies, enabling them to spread faster and cause concern among public health experts.
New SARS-CoV-2 Variants Rapidly Spreading Due to Antibody Evasion
The study led by teams from the Aaron Diamond AIDS Research Center, the Pandemic Research Alliance unit at Columbia, and the Department of Pathology and Epidemiology at the University of Michigan, highlights how newer versions of the Omicron JN.1 lineage are mutating to become either better at infecting cells or more resistant to immunity from vaccines or prior infections. This
Medical News report dives into the details of what sets these new variants apart and what that might mean for the future.
Immune Escape and Receptor Binding Altered in Latest Strains
Among the key findings, researchers discovered that the NB.1.8.1 and XFG variants show stronger resistance to neutralizing antibodies compared to earlier subvariants like LP.8.1.1. In vaccinated individuals, the ability of antibodies to neutralize these newer strains dropped by as much as 1.9-fold. Notably, five out of 20 vaccinated participants had antibody levels against NB.1.8.1 below detectable limits.
The study also analyzed how the virus’s spike protein mutations affect its ability to bind to the ACE2 receptor—the gateway the virus uses to enter human cells. LP.8.1 showed the highest ACE2-binding affinity, potentially explaining its explosive spread early in 2025. In contrast, NB.1.8.1 and XFG had lower binding strength but compensated through superior immune evasion. The XFG strain, now dominant in Europe and rising fast in North America, appears to be reverting to a familiar strategy used by older Omicron strains—focusing on dodging immunity rather than improving cell entry.
New Mutations Are Rewriting the Virus Playbook
Researchers noted that specific mutations, like A435S and A475V in the spike protein, help these variants evade key monoclonal antibodies used in both treatment and studies. Structural modeling showed how some mutations create steric hindrance, interfering with antibody binding. Other changes introduce electrostatic charges that reduce the virus’s visibility to the immune system.
The study concludes that the evolution of these SARS-CoV-2 variants represents a shift back toward immune evasion as the dominant survival strategy. While LP.8.1 gained ground with higher infectivity, newer strains like NB.1.8.1 and XFG are winning by escaping the immune system. This pattern of alternating tactics suggests the virus is becoming more unpredictable and harder to con
trol. The researchers stress the urgent need to update vaccines and therapies to keep pace with these rapidly evolving variants.
The study findings were published on a preprint server and are currently being peer reviewed.
https://www.biorxiv.org/content/10.1101/2025.07.18.662329v1
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