South African scientists monitor new variant of coronavirus

Since the coronavirus pandemic struck mankind, the scientific world has not only been concerned with understanding the dynamics of the circulation of the SARS-CoV-2 virus but also with detecting mutations that may complicate the fight for it. appease.

A group of researchers from The South African National Institute of Communicable Diseases and the KwaZulu-Natal Research Innovation and Sequencing Platform presented a new study in which a more mutated variant was detected compared to the parent virus., even proving to be the most mutated known to date.

A new variant of the coronavirus, C.1.2, has been detected in South Africa and several other countries over concerns that it is no longer infectious and that it will escape vaccines, research shows.

Scientists first detected C.1.2 in May 2021 and found it descended from C.1, which experts found surprising since C.1 was last detected in January. This line has “substantially mutated” from C.1 and is more distant from the original virus detected in the city of Wuhan, China.

The details of the investigation took into account any other variant of concern (VOC) or variant of interest (VOI) detected so far in the world.

Scientists consider that the number of C.1.2 sequences available may be an insufficient representation of the spread and frequency of the variant in South Africa and globally. The study found steady increases in the number of C.1.2 genomes in South Africa on a monthly basis, 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 Beta variants. Delta there.

According to genomic surveillance reports, and although it was first detected in South Africa, C.1.2 has since been found in England, China, Democratic Republic of Congo, Mauritius, New Zealand, Portugal and Switzerland.

Multiply the mutation rate by two

The South African National Institute of Communicable Diseases study, in prepress phase and not yet peer-reviewed, points out that this variant has “mutated considerably” compared to its original mutation.

Another big concern found is its mutation rate. It amounts to 41.8 mutations per year, almost twice as fast as the other variants. A mutation rate equivalent to this has already been observed in a short time in particularly virulent strains, such as Alpha, Beta or Gamma, explain the authors.

More than half of the C.1.2 sequences have 14 mutations, but additional mutations were seen in some of the sequences, suggesting that evolution within the lineage is underway, adds the article from South African practitioners.

Scientifically, it appears that more than half (about 52%) of the mutations in the tip region of C.1.2 sequences have already been observed in other variants of concern and variants of interest. The N440K and Y449H mutations, which have been associated with the leakage of certain antibodies, were also observed in the C.1.2 sequences.

With this in mind, the report makers point out that the combination of these mutations, along with changes in other parts of the virus, likely helps the virus escape antibodies and immune responses, even in patients who have already been infected. by the variants. Alpha or Beta.

Scientists have explained, however, that Further study is needed to understand the exact impact of these mutations and to see if they give the variant a competitive advantage over the Delta variant.

Vaccine efficacy

Although more data is lacking, the report specifically reflects “steady increases in C12 genomes in South Africa on a monthly basis, from 0.2% of genomes sequenced in May to 1.6% in June, then to 2%. % in July”.

The elements exposed, although insufficient, would suggest that the C.1.2 strain could escape immunization from COVID-19 vaccines. In addition, among the sequenced mutations of this variant, N440K and Y449H have already been associated with a risk of immune evasion.

The variant could be more resistant to vaccination but also to a previous infection caused by the Alpha or Beta variants due to the presence of these two mutations, underline the authors. However, having observed the variant mainly in a country with a low vaccination rate (9.3% of the South African population has a full vaccination schedule), it is still too early to draw conclusions about possible resistance to the vaccine.

To have conclusive definitions, the researchers say, it would be necessary to closely monitor the spread of the C.1.2 mutation in a widely vaccinated population.

Monitoring variants

The publication of this observation occurs when A doctor in Turkey has given indications that a new variant of the coronavirus has been detected in the country, with tests detecting mutations that were not found in the current variants named by the World Health Organization (WHO ).

Dr Lütfi Çamlı, president of the Izmir Medical Chamber, told Turkish media that doctors found a new variant unrelated to the other variants, reaching a rate of around 50-60% of cases in the northern province by Rize. For Çamlı, “It is not yet clear whether they actually found a new variant or if this was simply the result of false negativity in PCR tests.”

Last Wednesday, the WHO had identified four variants of concern (VOC) and four of interest (VOI). As of Thursday, the European Center for Disease Prevention and Control (ECDC) identified five and six respectively. All these, as well as those that can be detected, will be the subject of special monitoring.

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