BEIJING – China has detected seven infections of the Covid-19 sub-variant JN.1, the national disease control and prevention administration said on Dec 15.

The authorities said the prevalence level of JN.1 was currently “very low”, but they could not rule out the possibility of it becoming the dominant strain in China due to factors that included imported cases.

JN.1 now accounts for more than one-fifth of all cases in the United States, based on estimates on Dec 15 from the Centres for Disease Control and Prevention (CDC).

This uptick suggests that JN.1 could be more transmissible and better at slipping past people’s immune systems, the CDC said.

The agency said JN.1 cases will continue to rise as a proportion of total cases as the sub-variant is currently the fastest growing in the US.

JN.1 is closely related to the sub-variant BA.2.86 of the virus, which the CDC has been tracking since August.

It was first identified in Luxembourg and then later spread to Britain, Iceland, France and the US.

The CDC said JN.1 was first detected in the US in September and was earlier grouped with BA.2.86 in its data tracker.

The health agency added that there currently was no evidence that JN.1 presents an increased risk to public health relative to other currently circulating variants and an updated shot could keep Americans protected against the variant.

On Nov 27, CDC said the BA.2.86 sub-variant accounts for about 5 to 15 per cent of currently circulating variants. REUTERS