Explained: How deadly is the new COVID-19 variant C.1.2?

According to the study, C.1.2 lineage has a mutation rate of about 41.8 mutations per year, which is about twice as fast as the current global mutation rate of the other variants. (Representative image: Reuters)

Amid the rising worry of the Delta variant of COVID-19, a new variant of the deadly virus has been detected. South African scientists have detected the new variant of SARS-CoV-2, the virus which causes COVID-19, known as C.1.2.

The new variant has been detected in South Africa and many other countries globally. It could be more transmissible and evade protection provided by vaccines, according to a yet-to-be peer-reviewed study posted on the preprint repository MedRxiv on August 24.

Scientists from National Institute for Communicable Diseases (NICD) and the KwaZulu-Natal Research Innovation and Sequencing Platform (KRISP) in South Africa have said that the potential variant of interest, C.1.2, was first detected in the country in May 2021.

Since then, it has been found in China, the Democratic Republic of the Congo, Mauritius, England, New Zealand, Portugal and Switzerland as of August 13, the researchers have said.

The most worrying part of this variant is that it has more mutations than other variants of concern (VOCs) or variants of interest (VOIs) detected worldwide so far. According to the study, C.1.2 lineage has a mutation rate of about 41.8 mutations per year, which is about twice as fast as the current global mutation rate of the other variants.

Before going into the details about the new variant C.1.2, let’s know about variants in detail:

Variants explained

Genetic variants of SARS-CoV-2 have been emerging and circulating around the world throughout the COVID-19 pandemic. Since the outbreak of the contagion, multiple variants of SARS-CoV-2 have emerged across the world.

Of all the forms of the virus that causes COVID-19, the Delta variant causes more infections and spreads faster.

Classification of variants

The variants of COVID-19 have been divided into three categories:

Variant of Interest (VOI): A variant with specific genetic markers that have been associated with changes to receptor binding, reduced neutralization by antibodies generated against previous infection or vaccination, reduced efficacy of treatments, potential diagnostic impact, or predicted increase in transmissibility or disease severity, according to US Centers for Disease Control and Prevention.

Variant of Concern (VOC): A variant for which there is evidence of an increase in transmissibility, more severe disease (like increment in hospitalizations, death rate, etc), a significant reduction in neutralization by antibodies generated during previous infection or vaccination, reduced effectiveness of treatments or vaccines, or diagnostic detection failures.

Variant of High Consequence (VOHC): A variant of high consequence has clear evidence that prevention measures or medical countermeasures (MCMs) have significantly reduced effectiveness relative to previously circulating variants.

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Types of Variants

- Alpha - B.1.1.7: First identified in the United Kingdom, this variant may potentially cause more people to get sicker and to die.

- Beta - B.1.351: First identified in South Africa, this variant does not cause more severe illness or death than other variants, as per the given data. However, it was believed to spread more easily than the original version of the coronavirus, leading some countries to restrict travel to and from South Africa.

- Gamma - P.1: First identified in Japan and Brazil, this variant also does not cause more severe illness or death than other variants, as per the given data.

- Delta - B.1.617.2: First identified in India, this variant spreads much faster than other variants. According to a new British study, people who get COVID-19 from the extra-contagious delta variant are about twice as likely to be hospitalised as those who caught an earlier version of the coronavirus. The study, carried out by Public Health England (PHE) and Cambridge University and published in 'The Lancet' journal on August 28 confirms previous reports that Delta first identified in India is more infectious than Alpha first identified in Kent, England.

Also read | Vaccine boosters are likely to increase protection against variants, new research shows

Now, a new variant of SARS-CoV-2 has emerged - C.1.2. Here are the key points to know about the new COVID-19 variant:

> The study found consistent increases in the number of C.1.2 genomes in South Africa each month, rising from 0.2 percent of genomes sequenced in May to 1.6 percent in June and then to 2 percent in July. This is similar to the increases seen with the Beta and Delta variants in the country during early detection, said the authors of the study.

> C.1.2 lineage has a mutation rate of about 41.8 mutations per year. This is about twice as fast as the current global mutation rate of the other variants.

> Over half of the C.1.2 sequences have 14 mutations, but additional variations have been noticed in some of the sequences. Though these mutations occur in the majority of C.1.2 viruses, there is additional variation within the spike region of this lineage, suggesting ongoing intra-lineage evolution, said the authors.

> About 52 percent of the mutations in the spike region of the C.1.2 sequences have previously been seen in other VOCs and VOIs. The spike protein is used by the SARS-CoV-2 virus to infect and enter human cells, and most vaccines target this region.

> The mutations N440K and Y449H, which have been associated with immune escape from certain antibodies, have also been noticed in C.1.2 sequences. While these mutations are not characteristic of current VOCs/VOIs, they have been associated with escape from certain class 3 neutralising antibodies, the authors wrote.

> These mutations are likely to help the virus evade antibodies and immune response, including in patients who have already developed antibodies for the Alpha or Beta variants, the study revealed.

> The variant is a result of numerous mutations accumulated in C.1.2 line in the spike protein, which makes it a lot different than the original virus that was identified in China’s Wuhan in 2019, virologist Upasana Ray from Kolkata's CSIR-Indian Institute of Chemical Biology told news agency PTI.