JN.1 variant dominates US with 50% of Covid cases: CDC

The new highly transmissible JN.1 variant, from the lineage of Omicron variant of Covid, is now the dominant variant in the US, the Centers for Disease Control and Prevention (CDC) has said.

The variant, classified as a variant of interest (VOI) by the World Health Organization (WHO) due to its rapid spread, is currently present in about 41 countries. It was first detected in Luxembourg in August.

The proportion of JN.1 viruses over the past 2 weeks was up sharply, rising from 15-29 per cent to 39-50 per cent, the CDC said in its latest estimates, putting it far above the next most common variant, HV.1.

The CDC said it is also seeing an increasing share of infections caused by JN.1 in travellers, wastewater, and most world regions.

JN.1 is similar to its parent BA.2.86, but has an additional mutation (L455S) in the spike protein, which has immune-evasion properties.

“JN.1 continues to cause an increasing share of infections and is now the most widely circulating variant in the United States. For the two weeks ending on December 23, 2023, JN.1 is expected to account for 39-50 per cent of all SARS-CoV-2 variants,” the CDC said in its latest update on the variant.

“That’s an increase from the projected prevalence two weeks ago of 15-29 per cent. We’re also seeing an increasing share of infections caused by JN.1 in travellers, wastewater, and most regions around the globe,” it added.

The CDC said that JN.1’s continued growth suggests that the variant is either more transmissible or better at evading our immune systems than other circulating variants. However, it added that “it is too early to know whether or to what extent JN.1 will cause an increase in infections or hospitalisations”.

“The JN.1 variant has taken over in the US. It may not result in a spike of hospitalizations, but it’s definitely adding a significant burden of infections and subsequent risk of #LongCovid. Luckily, the XBB.1.5 booster helps protect against JN.1,” US physician-scientist Eric Topol, wrote in a post on X.

JN.1 is also becoming the dominant variant globally, causing spikes in infections, hospitalisations as well as deaths in some countries. As per the WHO, the global number of new Covid-19 cases has increased by 52 per cent during the last one month. The UN health body also reported an increase in hospital, ICU admissions as well as deaths globally. This includes India, currently seeing a surge in Covid cases.

India recorded 692 fresh cases of Covid in the last 24 hours, taking the total active caseload to 4,097, according to Union Health Ministry data on Thursday. The data also reported six deaths in the last 24 hours – two in Maharashtra, and one each in Delhi, Karnataka, Kerala, and West Bengal.

Further, the country has also detected a total of 157 cases of JN.1, from Kerala (78), Gujarat (34), Goa (18), Karnataka (8), Maharashtra (7), Rajasthan (5), Tamil Nadu (4), Telangana (2) and Delhi (1), according to the INSACOG.

Meanwhile, the CDC said that existing vaccines, tests, and treatments work against JN.1. “At this time, the spread of JN.1 does not appear to pose additional risks to public health beyond that of other recent variants. CDC is closely monitoring Covid-19 increases domestically and internationally and will communicate if the situation changes,” it said.