Increasingly Spreading Across North America

It has recently become prominent in Mexico and, like other variants, exhibits a mutation in the coronavirus spike protein. The “Mexican variant” was identified by a research group from the University of Bologna.

A research group from the Department of Pharmacy and Biotechnology at the University of Bologna analyzed more than one million SARS-CoV-2 genome sequences. This analysis led to the identification of a new variant that has mainly spread in Mexico in recent weeks, but has also been found in Europe. Their paper, published in the Journal of Medical Virology, presented the so-called “Mexican variant”, whose scientific name is T478K. Like other strains, this shows a mutation in the Spike protein, which allows coronaviruses to attach to and penetrate their target cells.

“This variant is spreading more and more among people in North America, especially in Mexico. To date, this variant covers more than 50% of the existing viruses in this field. The speed and speed of the spread are reminiscent of that of the ‘British variant’”, explains Federico Giorgi, the study coordinator and professor at the Department of Pharmacy and Biotechnology at the University of Bologna. “The mutation of the Spike protein is structurally located in the region of interaction with the human receptor ACE2. Coronaviruses attach to this receptor to infect cells, spreading the infection more effectively.”

Until April 27, 2021, the researchers began analyzing nearly 1.2 million sequenced samples of the SARS-CoV-2 genome found in international databases. The new T478K variant was detected in 11435 samples. This is double the number of samples that presented the same variant a month earlier. Such an increase since early 2021 worries the researchers.

The “Mexican variant” spreads evenly across men and women and age groups. This variant represents 52.8% of all sequenced coronaviruses in Mexico, while in the United States it occurs in only 2.7% of sequenced samples. As for Europe, the “Mexican variety” has spread weakly in Germany, Sweden and Switzerland. In Italy it is virtually non-existent with only 4 reported cases.

The mutation that characterizes this variant is located in a region of the Spike protein that is responsible for its interaction with the human receptor ACE2, which is the mechanism by which coronaviruses gain access to the cells. Similar mutations occur in all variants that have been the center of attention in recent months. Indeed, recent coronavirus variants are distinguished by their high infection rates, making them widespread in many parts of the world.

Researchers tested the action of T478K Spike protein with in silico simulations and found that this mutated protein can alter the surface electrostatic charge. Consequently, it can not only alter the interaction with the human ACE2 protein, but also with the antibodies of the immune system and thus hinder the efficacy of drugs.

“Thanks to the large amount of data available in international databases, we can monitor the situation in near real time by monitoring the spread of coronavirus variants across different geographic areas,” Giorgi concludes. “It will be critical to continue this effort in the coming months to act quickly and with efficient resources.”

“Preliminary Report on SARS-CoV-2 Spike Mutation T478K” is the title of the study published in the Journal of Medical Virology. The authors are Simone di Giacomo, Daniele Mercatelli, Amir Rakhimov and Federico Giorgi, all from the Department of Pharmacy and Biotechnology at the University of Bologna.

Reference: “Preliminary Report on Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Spike Mutation T478K” by Simone Di Giacomo, Daniele Mercatelli, Amir Rakhimov, and Federico M. Giorgi, May 5, 2021, Journal of Medical Virology.
DOI: 10.1002 / jmv.27062