There has been a surge in Covid-19 cases across the globe, especially of the virus’s JN.1 subvariant. In India, the first case of JN.1, which is a lineage of Omicron, was found in a 79-year-old woman in India. Now many states have reported a rise in the variant.
The Centers for Disease Control and Protection (CDC) recently termed it as the fastest-growing variant in the US.
But despite its high transmissibility rate, JN.1 hasn’t shown signs of severe illness. According to the WHO, JN.1’s growth advantage increased from just 3.3% of all the coronavirus cases between October 30 and November 5 to 27% a month later. Experts cite that this increased transmissibility rate is due to the strain’s ability to evade immunity and prolong the infection period.
This means that JN.1 could be more infectious and better at getting past the body’s immunity defence, more than its ancestral strain, according to the CDC. A recent study in Lancet, published on December 15, found that one mutation alone gives JN.1 the ability to evade immune response faster than its parent BA.2.86.
“With just one additional receptor binding domain mutation (L455S) compared to its predecessor BA.2.86, the JN.1 variant rapidly became predominant in France (figure A; appendix 1 p 12), surpassing both BA.2.86 and the so-called FLip (L455F+F456L) strains,” the authors wrote.
First identified in the United States in September 2023, this variant has captured attention due to its swift spread. “History of vaccination could be one of the reasons why JN.1 has not progressed to cause severe disease. An important step in the prevention would be to vaccinate the high-risk group comprising the elderly, people with malignancies, people on immunosuppressive medications, uncontrolled diabetes and patients with chronic liver and kidney disease,”