According to the Genomic Sequencing Consortium bulletin published
January 10 and uploaded Sunday, the heavily mutated Omicron variant is
now in community transmission stage in the country. It states that while
most Omicron cases have been asymptomatic or mild, hospitalisations
and ICU admissions are increasing in the country. Hence, the threat level
remains unchanged.
The statement from Indian SARS-CoV-2 Genomics Consortium (Insacog)
also warned against screening for the variant based on the s-gene
dropout.
The omicron variant has a high number of mutations, including 32 on its
spike protein or the s-gene that attaches with the human ACE2 receptor
— a specific protein that serves an entry point for the coronavirus — to
initiate the infection. However, due to the high number of mutations in
the s-gene, the kits fail to detect it.
The Omicron variant’s newly found BA.2 lineage does not lead to this s-
gene target failure and could thereby lead people to believe that it is not
an Omicron infection. “The BA.2 lineage is a substantial fraction in India
and the s-gene dropout-based screening is thus likely to give high false
negatives,” the statement said.
The bulletin also stressed on the need to change the sampling method for
genomic surveillance. “Omicron is in community transmission and
spreading internally. No longer through infected travellers alone,” it
noted.
