
Beware: A New COVID Variant Is Rising—What You Need to Know About NB.1.8.1!
2025-05-28
Author: John Tan
A New Player in the COVID Game
As the chill of winter sets in across Australia, COVID is back in the spotlight with an alarming new variant: NB.1.8.1. Recently labeled a "variant under monitoring" by the World Health Organization (WHO), this strain is making waves due to its growing prevalence and distinctive features.
The Current COVID Landscape
More than five years since the pandemic began, COVID-19 continues to surge in waves. Tracking infections has become trickier as fewer people report their cases. However, data indicates a steady rise in infections across Australia. As of early May 2025, genetic testing confirms that NB.1.8.1 is gaining ground, accounting for up to 40% of cases in states like Victoria compared to less than 10% in others.
In Western Australia, wastewater samples reveal that NB.1.8.1 is now the dominant strain, signaling its robust spread. Globally, the variant is also on the rise, moving from 2.5% to 10.7% of cases in just a month. Notably, regions in Asia, particularly Hong Kong and China, have seen it become the leading variant.
Origin of NB.1.8.1
First spotted in January 2025, NB.1.8.1 is a descendant of the Omicron family, stemming from a blend of the XDV lineage. This recombinant nature allows it to carry unique mutations that are raising eyebrows in the scientific community.
What Do Researchers Know So Far?
Similar to its predecessors, NB.1.8.1 showcases mutations on its spike protein—crucial for entering human cells through ACE2 receptors. Key mutations include T22N, F59S, and T478I. Though still early in the variant's emergence, preliminary studies have revealed some concerning insights: NB.1.8.1 shows the strongest binding to ACE2 among its compareable variants, which may enhance its infectivity.
Antibody studies indicate that immune responses from vaccinated or previously infected individuals are about 1.5 times less effective against NB.1.8.1 compared to earlier variants. This suggests infected individuals might be more contagious.
Recognizing the Symptoms
So, what should you look out for? Early evidence implies that NB.1.8.1 spreads more easily while possibly evading some immunity from past infections or vaccinations. However, there’s some good news: the WHO has not identified this variant as causing more severe illness than its predecessors.
Common symptoms mirror those of other Omicron variants, including sore throat, fatigue, fever, mild cough, and muscle aches, along with possible gastrointestinal issues.
Staying Protected with Vaccines
As NB.1.8.1 prepares to become a significant contender during Australia’s chilly respiratory season, public health teams are vigilant. Although studies indicate a dip in antibodies against this strain, the WHO reassures that existing vaccines still provide strong protection against severe illness.
With booster shots available that target the JN.1 lineage—closely related to NB.1.8.1—staying vaccinated remains a crucial defense strategy this winter.