South African researchers have identified another COVID-19 variant that is being dubbed the ‘most mutated’ strain of the viral disease so far.
According to a new study that is in preprint and awaits peer review, the new variant has been named C.1.2 and emerged first in May this year from South Africa during the third wave of Coronavirus in the country.
It has evolved from C.1 variants, one of the strains that dominated the first wave of Coronavirus in South Africa and that was last detected in January this year.
The C.1.2 variant has “mutated substantially” in comparison to C.1. It has also undergone the most mutations from the original COVID-19 strain that emerged from Wuhan, China, in December 2019 in comparison to all other variants of concern and variants of interest detected all over the world so far.
Mutation Details and Strain
Its mutation rate is 41.8 mutations per year, which is 1.7 times faster than the current global mutation rate shown by all other variants and 1.8 times faster than the original strain of the disease.
The increased rate of mutation over a short period is consistent with the evolution of Alpha, Beta, and Gamma variants. This means that a single evolution event, which was followed by a spike in COVID-19 cases, was behind the fast mutation rate.
Around 52% of the mutations identified in the spike protein of the C.1.2 variant have previously been identified in all other variants of concern and interest.
The C.1.2 strain’s mutations include D614G, which is common in all variants. It also includes E484K and N501Y, which are shared with Beta and Gamma variants, with E484K seen in Eta and N501Y in Alpha variant as well.
It has also shown N440K and Y449H mutations, which have been associated with escape from antibodies produced by existing COVID-19 vaccines and immune responses in patients who have already been infected with the Alpha or Beta variants.
Impact of This New Variant
More research is required to determine the functional impact of these mutations and to investigate whether it gives the strain advantage over the Delta variant, the study pointed out.
Furthermore, a consistent increase in the number of C.1.2 genomes in South Africa has been witnessed on a monthly basis, rising from 0.2% of genomes sequenced in May to 1.6% in June and then to 2% in July, similar to the increases seen with the Beta and Delta variants in the country.
As per the latest reports, around 100 sequences that match the C.1.2 lineage have been listed on the open-access database Global Initiative on Sharing Avian Influenza Data (GISAID).
Besides South Africa, the C.1.2 strain has been reported in China, England, New Zealand, Portugal, Switzerland, the Democratic Republic of Congo, and Mauritius as well.