A new coronavirus variant, C.1.2, has been detected in South Africa and a number of other countries, with concerns that it could be more infectious and evade vaccines, according to a new preprint study by South Africa’s National Institute for Communicable Diseases and the KwaZulu-Natal Research Innovation and Sequencing Platform. The study is awaiting peer review.
Scientists first detected C.1.2 in May 2021, finding that it was descended from C.1, which scientists found surprising as C.1 had last been detected in January. The new variant has “mutated substantially” compared to C.1 and is more mutations away from the original virus detected in Wuhan than any other Variant of Concern (VOC) or Variant of Interest (VOI) detected so far worldwide.
While first detected in South Africa, C.1.2 has since been found in England, China, the Democratic Republic of the Congo, Mauritius, New Zealand, Portugal and Switzerland.
The scientists believe that the number of available sequences of C.1.2 may be an underrepresentation of the spread and frequency of the variant in South Africa and around the world. The study found consistent increases in the number of C.1.2 genomes in South Africa 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 there.
The study also found that the C.1.2 lineage has a mutation rate of about 41.8 mutations per year, which is nearly twice as fast as the current global mutation rate of the other variants. The scientists stated that this short period of increased evolution was also seen with the Alpha, Beta and Gamma variants, suggesting that a single event, followed by a spike in cases, drove faster mutation rates.
More than half of the C.1.2 sequences have 14 mutations, but additional mutations have been noticed in some of the sequences, suggesting that evolution within the lineage is ongoing, according to the study.
More than half (about 52%) of the mutations in the spike region of the C.1.2 sequences have previously been seen in other VOCs and VOIs. The mutations N440K and Y449H, which have been associated with escape from certain antibodies, have also been noticed in C.1.2 sequences. The scientists stressed that the combination of these mutations, as well as changes in other parts of the virus, likely help the virusevade antibodiesand immune responses, including in patients who have already been infected with the Alpha or Beta variants.
The scientists added that further work is required to understand the exact impact of these mutations and to see if they give the variant a competitive advantage over the Delta variant.
