India is a witness to a mild revival in Kovid -19 cases, which is responsible for the emergence of two new variants: NB.1.8.1 and LF.7.

Recently, it was discovered in Tamil Nadu and Gujarat, these variants are in close observation by Health Officers and World Health Organization (WHO).

The presence of a new sub-dynasty was confirmed in the data of Indian Sars-Cov-2 Genomics Consortium (INSACOG), a central government agency.

What are NB.1.8.1 and LF.7?

Both nb.1.8.1 and LF.7 are sub-linage of the Omikron variants, especially descended from JN.1 subveriants, which remains a major tension in India, accounting for 53% of the sequential samples.

NB.1.8.1 was first identified in Tamil Nadu in April 2025, while in May, four cases of LF.7 were revealed in Gujarat.

These variants have also been informed in other Asian countries and are believed to have increased driving in China and Southeast Asia.

“Currently approved Covid-19 vaccines are expected to be effective for this version against symptomatic and serious illness. Despite cases and hospitalization in some countries where nb.1.8.1 is broad, current data does not indicate that this version leads to more serious illness than other types in circulation,” who said.

How are these variants mutated?

Both variants carry several mutations in spike proteins, which can increase their ability to overcome infections and immune reactions.

NB.1.8.1, for example, A435S, V445H, and T478i features mutation, which can increase its insecurity and immunity to avoid immunity.

Parents JN.1 Large L455S are known for mutation themselves, making it about 1.5 times more infectious than the first Omikron subveriants.

Symptoms and severity

Symptoms associated with nb.1.8.1 and LF.7 are similar to previous omikron infections: sore throat, fatigue, mild cough, fever, muscle pain, nasal congestion, headache, nausea, loss of appetite, and light gastrointestinal issues.

Most of the cases in India are light, in which patients are lower at home and hospitalized. Currently there is no evidence that these variants cause more serious illness or high mortality than the earlier strains.

Both nb.1.8.1 and LF.7 are classified by WHO as “variants under monitoring”, not as “variants of anxiety” or “variant of interest”, indicating that their public health risk is considered low at this stage.

Indian health officials are increasing genome sequencing and monitoring to track their spread, while experts recommend that vaccination continue, mask use in crowded places, and to follow hygiene measures.

While NB.1.8.1 and LF.7 are contributing to an increase in cases, they do not pose more threats than in previous Omikron subversives, and vigilance is the best course of action.