XBB.1.5 strain now dominant in Gujarat

Ahmedabad: The XBB.1.5 sub-variant of the COVID-19 virus, which now accounts for 90 per cent of new cases in the US according to recent news reports, is now the dominant sub-variant found in genome sequencing in Gujarat.

The Gujarat Biotechnology Research Centre (GBRC) sequenced the genomes of the past 50 confirmed COVID cases and found that 37 or 74 per cent of these samples - were of the XBB.1 branch. Of these, 20 were XBB.1.5, 14 of XBB.1, and three of XBB.1.9.

Most of these cases were recorded in Ahmedabad, Vadodara, Surat and Kutch districts, the analysis showed.

It is notable that the Indian SARS-CoV-2 Genomics Consortium (INSACOG) had indicated the presence of this sub-variant in 11 states of India and said that cases were on the rise. Even in Gujarat, XBB was the most prevalent sub-variant of Omicron in December. However, at that time, XBB.2 accounted for 35 per cent of the cases, XBB.5 for 13 per cent and XBB.1 for only 10 per cent.

The rise of the sub-variant coincides with the spike in COVID cases in the state. On February 9, active cases had been at an all-time low at four. On Monday, active cases reached 81. The spike started in the last week of February. The state also has a COVID patient on a ventilator after a long period of time.

Will this sub-variant assume worrying proportions? City-based experts said that it's too early to say, and unlikely. Dr Urvesh Shah, professor and head of the microbiology department at GCS Medical College, said the XBB variant is a recombinant of BA.2.10 and BA.2.75 sub-variants of Omicron, both of which were experienced by Gujarat earlier.

"Current data does not suggest there are substantial differences in disease severity for XBB infections. There is, however, evidence pointing to a higher reinfection risk, compared to other circulating Omicron sub-lineages. Whether the increased immune escape of XBB is sufficient to drive new infection appears to depend on the regional immune landscape as affected by the size and timing of previous Omicron waves, as well as vaccination coverage," he said.

Experts also said that while there is nearly 100 per cent coverage for both doses of COVID vaccines in the adult population in the state, the period for which neutralizing antibodies circulate in the blood is about four to six months. Thus, it's possible that those who already got infected earlier could get infected, albeit mildly. City hospitals also indicated that there are no hospitalizations related to COVID as of now.