What India should know of new Covid variant NB.1.8.1

By Dr Utkarsh Shah
Critical Care Medicine Specialist

As the world continues adapting to a post-pandemic reality, the emergence of a new COVID-19 variant—NB.1.8.1—is once again drawing attention from health experts. A sub-lineage of the Omicron family, this variant has been detected in India and several other countries, including China and the United States. While its spread is not yet classified as a new wave, the uptick in cases has prompted a renewed focus on surveillance and early response.

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What is NB.1.8.1?

NB.1.8.1 is an offshoot of the JN.1 lineage, which itself is part of the ever-mutating Omicron variant. Experts suggest that NB.1.8.1 has minor genetic tweaks that potentially make it more transmissible. Although it doesn't appear to cause more severe disease than previous variants, its high transmissibility means that even a small percentage of hospitalizations can overwhelm healthcare systems if infections surge rapidly.

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Current situation in India

India has begun to detect scattered cases of NB.1.8.1. According to INSACOG, cases were recently confirmed in Tamil Nadu and Gujarat, with genome surveillance continuing across major states. While there is no cause for panic, states like Kerala and Maharashtra have started witnessing marginal increases in daily caseloads. Hospitals in some districts, such as Satna in Madhya Pradesh, have restarted RTPCR testing for OPD and IPD patients. Health departments are also initiating refresher training for new medical officers to ensure readiness should cases spike suddenly.

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Early symptoms: similar, yet subtle changes

The early symptoms of NB.1.8.1 mirror those of earlier Omicron variants—cough, sore throat, fever, body ache, and fatigue. However, anecdotal reports suggest that gastrointestinal symptoms like diarrhea, nausea, or abdominal pain may be more common this time around. Importantly, many infections are being reported with mild or no fever, making symptom recognition slightly trickier. People may dismiss early warning signs, inadvertently aiding the spread.

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Who should be more cautious?

Elderly individuals, those with pre-existing comorbidities such as diabetes or cardiovascular diseases, and immunocompromised patients should remain especially vigilant. Even with mild symptoms, complications in such populations can escalate quickly.

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Preventive measures & vaccination

1. Current vaccines are still believed to provide significant protection against severe illness, though their effectiveness against infection may have waned over time. Experts strongly recommend booster doses for vulnerable groups and urge citizens to avoid vaccine fatigue. Meanwhile, basic precautions—masking in crowded spaces, hand hygiene, ventilation, and self-isolation in case of symptoms—remain as relevant as ever.

2. Final thoughts: The emergence of NB.1.8.1 serves as a reminder that the virus continues to evolve. While there is no need for alarm, awareness and responsibility are essential. Continued surveillance, timely testing, and community cooperation will be key to containing its spread. In a country like India, where population density can rapidly turn isolated cases into outbreaks, vigilance is our best vaccine.

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Published in Lokmat Times, Nagpur Main, Page No. 8, Jun 05, 2025