A preliminary study recently uploaded on the medRxiv preprint server, researchers detail the detection and characteristics of the C.1.2 variant of SARS-CoV-2, which has not yet been assigned a variant of interest (VOI) status, but which could potentially have increased transmission and immune escape potential.
The researchers describe how they identified a new SARS-CoV-2 variant, C.1.2. The first detection of this variant was during the third wave of infections in South Africa from May 2021 onwards, and has also been detected in seven other countries around the world.
New SARS-CoV-2 variants are commonly associated with new waves of infection. Like several other variants of concern (VOCs), C.1.2 has accumulated a number of substitutions beyond what would be expected from the background SARS-CoV-2 evolutionary rate. This suggests the likelihood that these mutations arose during a period of accelerated evolution in a single individual with prolonged viral infection through virus-host co-evolution. Deletions within the N-terminal domain have been evident in cases of prolonged infection, further supporting this hypothesis.
C.1.2 contains many mutations that have been identified in all four VOCs (Alpha, Beta, Delta and Gamma) and three VOIs (Kappa, Eta and Lambda) as well as additional mutations. Many of the shared mutations have been associated with improved ACE2 binding or furin cleavage, and reduced neutralisation activity, raising concern about the transmission potential of this variant. The next step is determining the functional impact of these mutations and to find out if they give it a replication advantage over the Delta variant.
The C.1.2 lineage is continuing to grow, and as of 20 August 2021, there were 80 C.1.2 sequences in GISAID, and the variant has now been detected in Botswana and in the Northern Cape of South Africa. Note that this study is yet to have the peer review process completed.
Source: MedRxiv
