Razor Blade Variant

Why in News?

The variant NB.1.8.1 (Nimbus) is under the spotlight due to its unique ‘razor blade’ throat symptom and increasing global spread.

• Razor Blade variant – The variant is officially named NB.1.8.1, which is a descendant of the Omicron variant.
• The term "razor blade" comes from patients reporting an extremely painful sore throat, like “swallowing a razor blade.”
• WHO classification – On May 23, 2025, the World Health Organization (WHO) listed NB.1.8.1 as a Variant Under Monitoring (VUM).

A Variant Under Monitoring (VUM) is a term used to signal to public health authorities that a variant may require prioritized attention, monitoring and investigate if this variant may pose an additional threat to global public health.

• Existing COVID-19 vaccines are expected to remain effective against this variant for symptomatic and severe disease.
• Symptoms – Similar to other Covid variants,
  • Fever
  • Severe sore throat (razor-blade-like)
  • Cough
  • Runny nose
  • Tiredness
• Current Global spread – NB.1.8.1 is increasing in proportion globally, while other variants like LP.8.1 are declining.
• It has shown higher transmissibility due to spike protein mutations.
• India’s situation – As of May 2025, 1 case of NB.1.8.1 was detected in Tamil Nadu and 4 cases of LF.7 were found in Gujarat.
• However, the dominant variant remains JN.1, comprising 53% of samples.
• A newer recombinant variant, XFG (Originated from two variants LF.7 + LP.81.2), has emerged since May 2025.
• Surveillance & genome sequencing – Genomic studies attribute recent surges to evolving Omicron sub-lineages.
• Severity and hospitalizations – So far, there is no evidence that NB.1.8.1 causes more severe disease than other circulating variants.
• Hospitalizations have increased in some countries, but not dramatically.
• Expert view in India – Indian doctors say COVID-19 is co-circulating with other seasonal infections and can expect spikes and dips, but no massive waves like in 2021.
• Recommended safety measures
  • Hand hygiene
  • Avoiding crowded places
  • Wearing masks, especially in vulnerable populations
  • Vaccination boosters as per national advisories
• Public health measures recommended – Continued emphasis on personal hygiene, masking in crowded areas, hand washing, and protecting the vulnerable population.
• The government advises vigilance but not panic, as health systems are better prepared.

Reference

The Hindu| Razor Blade Covid Variant