India has detected a new COVID-19 subvariant, NB.1.8.1, classified by the World Health Organization (WHO) as a “Variant Under Monitoring”. The variant was first identified in Tamil Nadu in April 2025, prompting enhanced genome sequencing and surveillance.
What Is NB.1.8.1?
NB.1.8.1 is a descendant of the Omicron lineage JN.1, carrying six mutations in the spike protein that may enhance transmissibility and immune evasion. Preliminary data suggest that NB.1.8.1 has a higher binding affinity to human receptors, making it potentially more contagious.
Symptoms of NB.1.8.1
Most symptoms remain similar to previous Omicron variants, including:
- Sore throat
- Fatigue
- Mild cough
- Fever
- Nasal congestion
- Headache
- Nausea
- Loss of appetite
- Gastrointestinal issues
India’s Response to NB.1.8.1
Despite the emergence of NB.1.8.1, India’s dominant strain remains JN.1, found in 53% of sequenced samples, followed by BA.2 (26%). The Union Health Ministry has ramped up surveillance, ensuring:
- Mandatory genome sequencing of all positive samples
- Daily case reporting on national portals
- Increased hospital preparedness
- Continued vaccination and booster drives
Should You Be Concerned?
Health experts emphasize that NB.1.8.1 does not appear to cause more severe illness than previous variants. Existing COVID-19 vaccines remain effective in preventing severe disease and hospitalization.
