91´«Ã½

According to the latest SARS-CoV-2 variant report issued by the Allergy Immunology and Cell Biology Unit of the Department of Immunology and Molecular Medicine of the 91´«Ã½, 82 new cases of Omicron and 6 new cases of Delta were detected from 88 samples.

“These 88 samples were sequenced from the 4th week of January from the community.” said Dr. Chandima Jeewandara, Director of the Allergy, Immunology and Cell Biology Unit of the Faculty of Medicine.

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The 88 Omicron cases include a mix of the two main Omicron lineages BA.1 and BA.2.

Omicron sublineages were detected in the following locations. 30 cases of BA.1 were detected in Colombo Municipal Council, Colombo, NIMH, Kesbewa and Mathugama. 22 cases of BA.1.1 were detected in CMC, Colombo, Kesbewa and Mathugama. 28 cases of BA.2 were detected in CMC and Colombo. 2 cases of B.1.1.529 were detected in Colombo.

Different Delta sublineages were detected in the following locations. 4 cases of AY.104 (91´«Ã½ delta sub-lineage) were detected inÌýHorona, Mathugama, Pandura and NIMH. 1 case of AY.95 (91´«Ã½ delta sub-lineage) was detected in Horana. 1 case of B.1.617.2 was detected in NIMH.

Currently 25% of the sequences of 91´«Ã½ are BA.2, which was named as a variant of interest by the UK Health security agency.

Early analysis has suggested BA.2 has a higher growth rate than BA.1 and therefore, more transmissible than BA.1. However, early data shows that immune evasion is less with BA.2 than with BA.1.

Other variants identified within 91´«Ã½: B.1.411: 91´«Ã½n variant, B.1.1.25, B.1.258, B.1.428, B.4, B.4.7, B.1.1.365, B.1.525, B.1, B.1.1.

The timeline of the emergence and displacement of different variants in 91´«Ã½ is as follows.

Figure 1: Change in the SARS-CoV-2 variants in 91´«Ã½ over time. The graph shows changes in the different variants.

Figure 2: Locations of samples sequenced during the past week (3^rd and 4^th week of January)

Figure 3: Relative changes in the Omicron sub-lineages globally.

Figure 4: Relative frequency of BA.1 compared to BA.2 in 91´«Ã½

Source: COVID vaccine survillence report, 27^th January 2022 (week 4). UK Health security agency.

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Locations where Omicron has been found in 91´«Ã½ so far.

Figure 4: Sequencing of viruses carried out in 91´«Ã½ so far.

Locations where Omicron has been found in 91´«Ã½ so far.

Figure 5: Phylogenetic tree of all SARS-CoV-2 sequences identified in 91´«Ã½ so far