What you need to know about Omicron subvariants XFG, NB.1.8.1 and LF.7 as India's Covid cases rise

Amid an uptick in Covid cases in some parts of the country, Director General of the Indian Council of Medical Research (ICMR) Dr Rajiv Behl Monday said the severity of infections as of now is generally mild and there was no cause for worry.

Speaking about new Covid variants being traced, he said genome sequencing of samples in the west and south have shown that the new variants are not severe and are Omicron sub-variants. These are LF.7, XFG, JN.1 and NB. 1.8.1.

The first three are more prevalent, Dr Behl said. "Samples from other places are being sequenced and we will know in a day or two if there are more variants."

The ICMR DG said there has been an uptick in cases --first from the south, then west and now from northern India. All these cases are being monitored through the Integrated Disease Surveillance Programme (IDSP).

Besides that, ICMR's nationwide respiratory virus sentinel surveillance network is keeping a watch on emerging infections and pathogens, he said.

"Whenever cases increase, we look at three things. It's dependent on three factors with the first being how transmissible it is, conversely how fast the cases are increasing. Previously we saw Covid cases double in two days, but this time it is not that cases are increasing rapidly."

Here's what you need to know about these Omicron subvariants:

LF.7 has been classified by the World Health Organization (WHO) as a Variant Under Monitoring, which means it is being closely tracked as its mutations have the possibility to influence the virus' behaviour. LF.7 has itself mutated from the JN.1 variant.

XFG: This subvariant, also a descendant of JN.1, is being actively tracked by health officials in countries like India and the United States. A study by Chinese experts that has not yet been peer-reviewed claims XFG, along with other variants, "exhibit enhanced growth advantages over LP.8.1.1, suggesting their potential to dominate future transmission waves."

NB.1.8.1: The WHO has also given VUM status to this subvariant. The earliest sample of this variant was collected on January 22, 2025. The WHO has noted that this subvariant is growing rapidly. It has also demonstrated a higher transmissibility rate compared to earlier variants.

With PTI inputs