India’s new type of Covid appears to be the most contagious of all

A new subtype of Omicron, called BA.2.75which has been identified in India and already reported in several countries, including Japan, Germany, the United Kingdom, Canada, the United States, Australia and New Zealand, has several mutations that scientists fear may be the worst emerging of the COVID-19 pandemic.

According to experts, it will be a “second-generation variant” derived from the Omicron BA.2 subtype, which is characterized by new mutations at the level of the Spike protein, in addition to those already present in BA.2, Including the “G446S” and “R493Q” variants, They are of particular interest, as they would give the variant the ability to evade different antibodies and bind human cells with greater affinity. In other words, this antigen profile would allow the new BA.2.75 subvariant to escape from antibodies caused by previous infections and vaccination and have a greater potential to infect people who have been infected before, as well as those who have been vaccinated.

Thomas Peacock, a scientist at Imperial College London, said in a Twitter thread that the new sub-alternative was “worthy of attention”, as It can be particularly contagious It has a high ability to infect people who have been treated and vaccinated.

Molecular biologist Ulrich Elling of the Institute of Molecular Biotechnology (IMBA) of the Austrian Academy of Sciences agrees. “I do not like the observed mutations. Before we finish the wave caused by the variable BA.5, we may need to prepare for the next wavewrote on Twitter. The expert notes that the number of BA cases 2.75 in India is increasing rapidlyalthough so far no official data has been released either by the Indian government or by the SARS-CoV-2 Genome Consortium (INSACOG), the genome monitoring agency operating under the Ministry of Health.

What do we know about the Omicron BA.2.75 sub-variable?

As mentioned, this variant BA.2.75 has been named on the basis of investigations by scientists from the Indian states of Maharashtra, Karnataka and Jammu and Kashmir. INSACOG Scientist Al . said Times of India: “We studied how BA.2, which launched the third wave mainly in January, still caused infection and re-infection in June. This led to the discovery of BA 2.75, which has more than 80 mutations, while BA.2 has about 60. Now, when we re-analyze the ancient BA.2 samples for these newly identified mutations, we find that the viruses belong to the BA.2.74, BA.2.75 and BA.2.76 subfamilies. “

Rather, to describe the two mutations “G446S” and “R493Q” The Omicron BA.2.75 sub-variable was distinguished by the Bloom Laboratory of the Fred Hitch Research Institute in the United States, which highlighted the presence of an “appreciable antigenic change with respect to the original BA.2”. boom G446S is found at “one of the strongest antibody escape sites.” Because of current vaccines they still deviate from BA.2. Therefore, for immunity from vaccines or early infection, adding G446S to BA.2 will reduce neutralization, the lab said. However, G446S would have little effect on the antibodies of people with previous BA infection. Therefore, the antigenic advantage of BA.2.75 over BA.2 would be more pronounced in subjects who were not exposed to BA.1.” This means that “BA.2.75 will elude antibodies in a similar manner to BA.4 and BA.5 compared to with the current vaccine.

On the other hand, the R493Q . mutation It appears to increase the virus’s ability to bind to the ACE2 receptor, the protein on the surface of human cells that the virus uses to penetrate them. Libby Thukral, a scientist at the Council for Scientific and Industrial Research-Institute of Genomics and Integrative Biology (CSIR-IGIB) in Delhi, said, printing: “This proportions May require urgent attention Because most mutations are unique and [esso] It has also changed its physicochemical character greatlyIsraeli medical expert Dr. Shai Fleishon of the Central Virology Laboratory at the Sheba Medical Center in Tel Hashomer noted that the increase in cases associated with this sub variant is “to an unprecedented level with other second generation variants derived from other worrisome variants“.

In other words, compared to the second-generation variants identified so far only in a few cases within a region, BA.2.75 has already been detected in more countries. “The fact that such a second-generation variant can be successful among guests is troubling. Means that […] It may even improve over timeFleishon said.