NEW DELHI: The new Covid-19 variant 'FLiRT', which is spreading fast in the US, is capable of evading the immune system due to a trans substitution of amino acids between two spike proteins, the experts said on Sunday.

FLiRT, which belongs to Omicron's JN.1 lineage, is rapidly replacing the previous variant, Eris, in the US, the UK, New Zealand, and South Korea, according to Rajeev Gupta, Director of Internal Medicine at the CK Birla Hospital (R), Delhi.

"A recent increase in hospitalisation rates in these countries has been attributed to this variant; however, it has remained a relatively small wave. The overall mortality rate has not increased," Gupta told IANS.

According to the Infectious Disease Society of America, the nickname 'FLiRT' is based on the technical names for their mutations.

The World Health Organisation (WHO) has reclassified it as a variant of interest and advised close monitoring.

According to Dhiren Gupta, a Pediatric Intensivist at Sir Ganga Ram Hospital, these new strains will keep emerging.

"Fortunately, none of the Omicron lineage is able to induce significant lung damage as delta strain did but limited to the upper respiratory tract. The surveillance and vigilance should be kept for major drift in virus," he said.

According to the experts, the increased use of monoclonal antibodies could be driving this mutation.

The symptoms of the new variant are similar to those of other Omicron subvariants, such as sore throat, cough, fatigue, nasal congestion, runny nose, headache, muscle aches, fever, and possible loss of taste and smell, the experts mentioned.