Covid-19 C.1.2 strain found in all provinces at ‘relatively low frequency’
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Cape Town - Health authorities are on high alert following the detection of the highly mutated coronavirus strain, C.1.2.
In a media briefing on Monday, experts from the National Institute for Communicable Diseases (NICD) said C.1.2 has been detected in all provinces in South Africa at relatively low frequency since May.
While the C.1.2 lineage shares a few common mutations with the Beta and Delta variants, the new lineage is between 44-59 mutations away from the original Wuhan virus.
NICD Principal Medical Scientist Jinal N. Bhiman said this has raised alarm.
“While the Delta variant continues to dominate infection, C.1.2 has been detected at low frequencies, less than 3% of sequences.
“It shares some mutations with the other variants of concern (VOC) or variants of interest (VOI), but also unique mutations that flagged our attention. It raised a bit of alarm for us.”
The NICD’s Professor Penny Moore said based on their understanding of the mutations in this variant, they suspect that it might be able to partially evade the immune response, but despite this, that vaccines will still offer high levels of protection against hospitalization and death.
“We have considerable confidence that the vaccines being rolled out in South Africa will continue to protect us from severe disease and death,” she said.
The researchers said there was no need to review lockdown restrictions at this stage.
There was a publication on Friday of data on pre-print server medRxiv that researchers from the NICD, SA Medical Research Council and the KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP) among others, had identified a potential variant of interest (VOI) in C.1.2.
This lineage was first identified in May 2021 and evolved from C.1, one of the lineages that dominated the first wave of SARS-CoV-2 infections in South Africa but last detected in January.
C.1.2 contains multiple substitutions within the spike protein, which have been associated with increased transmissibility and reduced neutralization sensitivity.
“We see consistent increases in the number of C.1.2 genomes in South Africa on a monthly basis, where in May C.1.2 accounted for 0.2% of genomes sequenced, in June 1.6% and in July 2.0%, similar to the increases seen in Beta and Delta in South Africa during early detection.”
“Future work aims to determine the functional impact of these mutations, which likely include neutralizing antibody escape, and to investigate whether their combination confers a replicative fitness advantage over the Delta variant. The C.1.2 lineage is continuing to grow.”
The National health department and World Health Organization were alerted to circulation of the lineage in July.