Mumbai: Despite the recent discovery of the BF.7 variant in the state, genome research experts indicate the XBB and BA.2.75 strains are still the most prevalent locally and will be closely monitored.
Some experts believe the BF.7 strainwhich has originated from the BA.5 variant of omicronmay not pose a significant threat to India and the likelihood of XBB causing more Covid infections could be higher.
State officials said XBB, a combination of two BA.2 sublineages, is present in over half of the samples tested, while the remaining samples typically contain the BA.2.75 strain. The BA.2.75 variant was prevalent last year before the emergence of XBB, but recent genome sequencing data indicates BA.2.75 and its sublineages have made a resurgence.
Recently, the genome sequencing of a 59-year-old woman who died in December revealed she had been infected with the XBB.1 strain. Sixty-one samples from the city and outskirts were tested, and their genome sequencing report revealed the XBB sub-variant. The woman, from K West ward, had developed a dry cough and breathlessness around December 6. As her condition worsened, she was moved to a BMC hospital from a private set-up and passed away on December 14 from septic shock and acute respiratory distress. syndrome. A civic official highlighted that she had underlying comorbidities, including a connective tissue disorder (myositis) known to decrease immunity. Notably, she was fully vaccinated with 2 doses.
“BF.7 is a subvariant of BA.5, which has not managed to cause much trouble in India although it has been responsible for infection surges abroad. We plan to study why BA.5 has not had a similar impact in India,” said Dr Rajesh Karyakarte, who coordinates SARS-CoV-2 genetic sequencing in Maharashtra,
The WHO, in a recent report, said countries should take note of XBB and its descendant XBB.1.5. From October 22, 2022, to January 11, 2023, 5,288 sequences of the Omicron XBB.1.5 variant have been reported in 38 countries. XBB’s descendants XBB.1 and XBB.1.5 have been found to have high immune escape properties, although none have been found to carry any mutation that can be associated with greater severity. Dr Karyakarte said they would carry out the genome sequencing of a 68-year-old man who died in Mumbai last week.
Dr Jayanti Shastri, former head of Kasturba Hospital’s molecular diagnostics lab, said new variants shouldn’t be a cause for worry as they are mainly sub-lineages. A civic doctor said as long as Omicron’s sub-variants are circulating, Indians can relax.