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HomeHealth & FitnessNB.1.8.1 COVID-19 variant cases and symptoms: 7 things to know about this new COVID-19 strain

NB.1.8.1 COVID-19 variant cases and symptoms: 7 things to know about this new COVID-19 strain

NB.1.8.1 is a new COVID-19 variant spreading rapidly across several countries. It may cause symptoms like cough, fatigue, and mild fever. While under close watch, continuing safety measures and vaccination is essential. Stay informed and cautious to reduce risk. Here’s all you need to know.

May 26, 2025 / 12:16 IST
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Kerala remains the most affected, accounting for 335 of the new cases, pushing its active caseload to 430.

The ever-evolving nature of COVID-19 means new variants continue to emerge, keeping the doctors on their toes. One of the latest variants causing concern globally is NB.1.8.1. Here’s what you should know about this new variant:


NB.1.8.1 is a newly identified variant of the COVID-19 virus detected through genomic surveillance in countries including India, Taiwan, Hong Kong, and the United States. Although the World Health Organization (WHO) hasn’t officially labelled it as a Variant of Interest yet, it’s being closely monitored due to its rapid spread.

Also read | New Covid-19 variants reported in India as cases surge; Delhi issues advisory, Uttarakhand on high alert


Cases have been reported in several parts of the world, from Tamil Nadu and Gujarat in India to major US airports and even in Taiwan, where it was the predominant strain causing thousands to seek medical care in late April and early May 2025.
Scientists have noted key mutations in NB.1.8.1’s spike protein (such as A435S, V445H, and T478I) that could increase how easily the virus spreads and help it evade immune responses. An Australian researcher has observed that NB.1.8.1 may grow faster than other existing variants, suggesting it could quickly become more widespread.
Infections have been associated with symptoms like persistent cough, sore throat, fatigue, nausea, and even unusual signs such as blurred vision and low-grade hyperthermia, which is a mild rise in body temperature without a full fever.

Also read | How to protect yourself from norovirus, COVID-19, flu and RSV


While WHO is still reviewing this variant, local health organisations like India’s INSACOG and Taiwan’s CDC are already monitoring it. They're reminding everyone to keep wearing masks in crowded places, wash hands often, stay home when sick, and keep up with vaccinations.
Vaccine companies  are working on updates to their COVID-19 shots to make sure they protect against newer variants like NB.1.8.1. Disclaimer: This article, including health and fitness advice, only provides generic information. Don’t treat it as a substitute for qualified medical opinion. Always consult a specialist for specific health diagnosis.

Namita S Kalla is a senior journalist who writes about different aspects of modern life that include lifestyle, health, fashion, beauty, and entertainment.
first published: May 26, 2025 12:14 pm

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