COVID-19 makes a quiet return: India detects NB.1.8.1 variant as JN.1 drives 53% of infections

Just as COVID-19 seemed to be receding into the background, new sub-variants are reigniting global concern. In India, a case of the emerging NB.1.8.1 strain and four cases of LF.7 have been detected, coinciding with a steady rise in infections across South Asia. According to the Indian SARS-CoV-2 Genomics Consortium (INSACOG), the JN.1 variant — already dominant at 53% of samples — is driving the current wave, alongside its fast-mutating offspring.

The uptick in COVID-19 cases is being linked to the spread of highly transmissible variants and a waning population-wide immunity. With most people having previously contracted the virus, natural protection is now wearing off.

The JN.1 strain, a descendent of the BA.2.86 lineage (also known as 'Pirola'), has outpaced earlier variants due to its ability to spread rapidly and partially evade existing immunity. It carries more than 35 mutations in its spike protein, especially in the receptor-binding domain, which helps it latch onto human cells more effectively.

According to Yale Medicine, JN.1 transmits more easily than sub-variants like XBB.1.5 and can slip past antibodies from past infections or vaccinations — though not entirely.

LF.7 and NB.1.5, both sub-lineages of JN.1, are now under the World Health Organization’s radar as Variants Under Monitoring. NB.1.8.1, which features mutations like A435S, V445H, and T478I, is also in the spotlight for its potential to dodge immune defenses. While classified as low-risk globally, these strains are linked to new infection surges in China and parts of Asia.

INSACOG data reveals that JN.1 dominates sequencing in India, followed by BA.2 (26%) and other Omicron descendants (20%). The only NB.1.8.1 case in India was reported in Tamil Nadu in April, while LF.7 appeared in four cases in Gujarat in May.

Singapore and Hong Kong have seen over 70% of sequenced infections in recent weeks caused by LF.7 and NB.1.5. In Singapore, weekly cases spiked from 11,100 in late April to over 14,000 in early May.

Despite the rise, health experts say there’s no need for panic. “COVID-19 is cyclical,” noted Indian health officials, suggesting waves could return every six to nine months. But widespread prior immunity from vaccination and past infection has kept severity in check.

In India, as of May 19, only 257 active cases were reported, mostly from Kerala, Maharashtra, and Tamil Nadu. A high-level review by the Directorate General of Health Services concluded that the situation remains under control.

Still, experts caution that complacency isn’t an option. The virus hasn’t vanished—it’s evolved. And so must our vigilance.