Maharashtra on Wednesday reported that it has detected 18 cases of XBB, a sub-variant of the Omicron variant of the coronavirus, between September 24 and October 11, reported ANI.

XBB and its sub-lineage XBB.1 have been reported in Maharashtra, West Bengal, Odisha and Tamil Nadu, according to The Hindu.

Data from Maharashtra released earlier showed that the XBB variant had a growth advantage over its parent lineage, the BA.2.75, and had far greater immune evasive nature. According to state epidemiologist Dr Pradeep Awate, the data also suggests that BA.2.75, which comprised 95% of total genetically sequenced Covid-19 samples in Maharashtra, has come down to 75% over last few weeks.

However, it is yet to be known whether XBB and XBB.1 are more severe than other Omicron variants that are in circulation.

On Wednesday, the Maharashtra health department said that 13 cases of XBB variant were detected in Pune district, two each in Nagpur and Thane and one in Akola. Besides XBB, Maharashtra also found one cases each of BQ.1 and BA.2.3.20 variants.

It said that 15 of these patients were vaccinated against the coronavirus disease and information about the remaining five are yet to be received.

The department pointed out that the Covid-19 cases were mild in nature and advised citizens not to panic but to take appropriate precaution against the infection.

Randeep Guleria, the chairperson of the Confederation of Indian Industry’s Public Health Council and former director of All India Institute of Medical Sciences New Delhi, also advised citizens to wear masks in crowded areas but suggested that they should not panic, reported ANI.

“New variants of Covid-19 are expected which have the tendency to mutate,” he told the news agency. “Situation is different now, earlier there was no vaccination but people are vaccinated now and have developed immunity against the virus...The chances of hospitalisation and ICU [Intensive Care Unit] admissions are low.”

He, however, advised high-risk groups and elderly citizens to avoid going out as there were high chances of them spreading the infection.

Meanwhile, Maharashtra on Wednesday recorded 418 new coronavirus cases, pushing its overall infection tally to 81,28,276. With three deaths, the toll climbed to 1,48,377.

What is XBB variant?

The Omicron variant of coronavirus first made appearance in South Africa in November. Since then, Omicron has diversified into a family of sub-lineages. Its first two main sub-lineages were BA.1 and BA.2. Both have further branched out.

XBB has originated – or formed as a mutation of – from two strains of BA.2, the BA.2.75, a fast circulating variant, and BJ.1, which does not have fast transmissibility like BA.2.75 but has managed to infect a sizeable population globally.

Countries like Singapore, Australia, Japan, Bangladesh, Denmark, USA have also reported the XBB variant.

Dr Rajesh Karyakarte, dean in the BJ Medical College that is part of Indian SARS-CoV-2 Consortium on Genomics, or INSACOG, said that the severity of the variant remains unknown but initial data suggest it causes mild illness. More samples of hospitalised patients are being collected to assess severity.

INSACOG is a network that monitors mutations in coronavirus.